2021-08-13 15:26:38

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 0/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and use in DRM

hi Jason, Greg, Daniel, dri-everyone,

drm_debug_enabled() is called a lot (by drm-debug api) to do unlikely
bit-tests to selectively enable debug printing; this is a good job for
DYNAMIC_DEBUG, IFF it is built with JUMP_LABEL.

This patchset enables the use of dynamic-debug to avoid those
drm_debug_enabled() overheads, if CONFIG_DRM_USE_DYNAMIC_DEBUG=y.

v5: much rework

- based on Daniel Vetter's feedback, not RFC anymore. (except last one)

- move POC bit_map callback code into dynamic_debug
add .data to struct kernel_param
add DEFINE_DYNAMIC_DEBUG_CATEGORIES :
a declarative interface for bits => control-queries
this is all new functionality.

- use DEFINE_DYNAMIC_DEBUG_CATEGORIES in i915, amdgpu
adds selectivity/control to existing categorizations

- DRM_USE_DYNAMIC_DEBUG
replace DRM_UT_<CAT> (an enum)
with DRM_CAT_<CAT> (a prefix string, cpp-prepended to format)
_UT_ still present, drm_debug_enabled() still used
todo:
change __drm_debug param-var to read DDD_CATEGORIES's param-var
might suffice to keep parallel schemes coherent.

- RFC add tracer func as syslog alternate
test_dynamic_debug.ko: uses tracer for observability, does selftest
has some misuse risk; calling pr_debug recursively.

v4: (brown-bagger, various fixes after snips)
v3: fixes missed SOB, && on BOL, commit-log tweaks
v2: https://lore.kernel.org/lkml/[email protected]/
v1: https://lore.kernel.org/lkml/[email protected]/

Doing so creates many new pr_debug callsites,
otherwise i915 has ~120 prdbgs, and drm has just 1;

bash-5.1# modprobe i915
dyndbg: 8 debug prints in module video
dyndbg: 305 debug prints in module drm
dyndbg: 207 debug prints in module drm_kms_helper
dyndbg: 2 debug prints in module ttm
dyndbg: 1720 debug prints in module i915

On amdgpu, enabling it adds ~3200 prdbgs, currently at 56 bytes each.
So CONFIG_DRM_USE_DYNAMIC_DEBUG=y affects resource requirements.
Im working on a diet-plan.

Im running this patchset bare-metal on an i7/i915 laptop & an
r9/amdgpu desktop (both as loadable modules). I booted the amdgpu box
with:

BOOT_IMAGE=(hd2,gpt2)/vmlinuz-5.14.0-rc4-d7a-00009-g5db471cba844 \
root=UUID=mumble ro \
rootflags=subvol=root00 rhgb \
dynamic_debug.verbose=3 main.dyndbg=+p \
amdgpu.debug=1 amdgpu.test=1 \
"amdgpu.dyndbg=format ^[ +p"

That last line enables ~1700 prdbg callsites with a format like '[DML'
etc at boot, and amdgpu.test=1 triggers 90 seconds of tests, yielding
~76k prdbgs in 409 seconds, before I turned them off with:

echo module amdgpu -p > /proc/dynamic_debug/control

Its worth noting, this changes the dyndbg-state underneath settings
applied with `echo > parameters/debug`; the latter is qualitatively
writeonly, maybe a param_get should return "NA" "-1"

this merged cleanly, on top of
commit d65ef4634e5c795a6a4df1d198992c70e9692fb3 (drm-tip/drm-tip)

Jim Cromie (9):
drm/print: fixup spelling in a comment
moduleparam: add data member to struct kernel_param
dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks
i915/gvt: remove spaces in pr_debug "gvt: core:" etc prefixes
i915/gvt: use DEFINE_DYNAMIC_DEBUG_CATEGORIES to create "gvt:core:"
etc categories
amdgpu: use DEFINE_DYNAMIC_DEBUG_CATEGORIES to control categorized
pr_debugs
drm_print: add choice to use dynamic debug in drm-debug
amdgpu_ucode: reduce number of pr_debug calls
dyndbg: RFC add tracer facility RFC

drivers/gpu/drm/Kconfig | 13 +
drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c | 293 ++++++++++--------
.../gpu/drm/amd/display/dc/core/dc_debug.c | 44 ++-
drivers/gpu/drm/drm_print.c | 49 ++-
drivers/gpu/drm/i915/gvt/Makefile | 4 +
drivers/gpu/drm/i915/gvt/debug.h | 18 +-
drivers/gpu/drm/i915/i915_params.c | 35 +++
include/drm/drm_print.h | 143 +++++++--
include/linux/dynamic_debug.h | 82 ++++-
include/linux/moduleparam.h | 11 +-
lib/Kconfig.debug | 10 +
lib/Makefile | 1 +
lib/dynamic_debug.c | 171 ++++++++--
lib/test_dynamic_debug.c | 247 +++++++++++++++
14 files changed, 901 insertions(+), 220 deletions(-)
create mode 100644 lib/test_dynamic_debug.c

--
2.31.1


2021-08-13 15:26:49

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 8/9] amdgpu_ucode: reduce number of pr_debug calls

There are blocks of DRM_DEBUG calls, consolidate their args into
single calls. With dynamic-debug in use, each callsite consumes 56
bytes of ro callsite data, and this patch removes about 65 calls, so
it saves ~3.5kb.

no functional changes.

Signed-off-by: Jim Cromie <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c | 293 ++++++++++++----------
1 file changed, 158 insertions(+), 135 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
index 2834981f8c08..14a9fef1f4c6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
@@ -30,17 +30,26 @@

static void amdgpu_ucode_print_common_hdr(const struct common_firmware_header *hdr)
{
- DRM_DEBUG("size_bytes: %u\n", le32_to_cpu(hdr->size_bytes));
- DRM_DEBUG("header_size_bytes: %u\n", le32_to_cpu(hdr->header_size_bytes));
- DRM_DEBUG("header_version_major: %u\n", le16_to_cpu(hdr->header_version_major));
- DRM_DEBUG("header_version_minor: %u\n", le16_to_cpu(hdr->header_version_minor));
- DRM_DEBUG("ip_version_major: %u\n", le16_to_cpu(hdr->ip_version_major));
- DRM_DEBUG("ip_version_minor: %u\n", le16_to_cpu(hdr->ip_version_minor));
- DRM_DEBUG("ucode_version: 0x%08x\n", le32_to_cpu(hdr->ucode_version));
- DRM_DEBUG("ucode_size_bytes: %u\n", le32_to_cpu(hdr->ucode_size_bytes));
- DRM_DEBUG("ucode_array_offset_bytes: %u\n",
- le32_to_cpu(hdr->ucode_array_offset_bytes));
- DRM_DEBUG("crc32: 0x%08x\n", le32_to_cpu(hdr->crc32));
+ DRM_DEBUG("size_bytes: %u\n"
+ "header_size_bytes: %u\n"
+ "header_version_major: %u\n"
+ "header_version_minor: %u\n"
+ "ip_version_major: %u\n"
+ "ip_version_minor: %u\n"
+ "ucode_version: 0x%08x\n"
+ "ucode_size_bytes: %u\n"
+ "ucode_array_offset_bytes: %u\n"
+ "crc32: 0x%08x\n",
+ le32_to_cpu(hdr->size_bytes),
+ le32_to_cpu(hdr->header_size_bytes),
+ le16_to_cpu(hdr->header_version_major),
+ le16_to_cpu(hdr->header_version_minor),
+ le16_to_cpu(hdr->ip_version_major),
+ le16_to_cpu(hdr->ip_version_minor),
+ le32_to_cpu(hdr->ucode_version),
+ le32_to_cpu(hdr->ucode_size_bytes),
+ le32_to_cpu(hdr->ucode_array_offset_bytes),
+ le32_to_cpu(hdr->crc32));
}

void amdgpu_ucode_print_mc_hdr(const struct common_firmware_header *hdr)
@@ -55,9 +64,9 @@ void amdgpu_ucode_print_mc_hdr(const struct common_firmware_header *hdr)
const struct mc_firmware_header_v1_0 *mc_hdr =
container_of(hdr, struct mc_firmware_header_v1_0, header);

- DRM_DEBUG("io_debug_size_bytes: %u\n",
- le32_to_cpu(mc_hdr->io_debug_size_bytes));
- DRM_DEBUG("io_debug_array_offset_bytes: %u\n",
+ DRM_DEBUG("io_debug_size_bytes: %u\n"
+ "io_debug_array_offset_bytes: %u\n",
+ le32_to_cpu(mc_hdr->io_debug_size_bytes),
le32_to_cpu(mc_hdr->io_debug_array_offset_bytes));
} else {
DRM_ERROR("Unknown MC ucode version: %u.%u\n", version_major, version_minor);
@@ -82,13 +91,17 @@ void amdgpu_ucode_print_smc_hdr(const struct common_firmware_header *hdr)
switch (version_minor) {
case 0:
v2_0_hdr = container_of(hdr, struct smc_firmware_header_v2_0, v1_0.header);
- DRM_DEBUG("ppt_offset_bytes: %u\n", le32_to_cpu(v2_0_hdr->ppt_offset_bytes));
- DRM_DEBUG("ppt_size_bytes: %u\n", le32_to_cpu(v2_0_hdr->ppt_size_bytes));
+ DRM_DEBUG("ppt_offset_bytes: %u\n"
+ "ppt_size_bytes: %u\n",
+ le32_to_cpu(v2_0_hdr->ppt_offset_bytes),
+ le32_to_cpu(v2_0_hdr->ppt_size_bytes));
break;
case 1:
v2_1_hdr = container_of(hdr, struct smc_firmware_header_v2_1, v1_0.header);
- DRM_DEBUG("pptable_count: %u\n", le32_to_cpu(v2_1_hdr->pptable_count));
- DRM_DEBUG("pptable_entry_offset: %u\n", le32_to_cpu(v2_1_hdr->pptable_entry_offset));
+ DRM_DEBUG("pptable_count: %u\n"
+ "pptable_entry_offset: %u\n",
+ le32_to_cpu(v2_1_hdr->pptable_count),
+ le32_to_cpu(v2_1_hdr->pptable_entry_offset));
break;
default:
break;
@@ -111,10 +124,12 @@ void amdgpu_ucode_print_gfx_hdr(const struct common_firmware_header *hdr)
const struct gfx_firmware_header_v1_0 *gfx_hdr =
container_of(hdr, struct gfx_firmware_header_v1_0, header);

- DRM_DEBUG("ucode_feature_version: %u\n",
- le32_to_cpu(gfx_hdr->ucode_feature_version));
- DRM_DEBUG("jt_offset: %u\n", le32_to_cpu(gfx_hdr->jt_offset));
- DRM_DEBUG("jt_size: %u\n", le32_to_cpu(gfx_hdr->jt_size));
+ DRM_DEBUG("ucode_feature_version: %u\n"
+ "jt_offset: %u\n"
+ "jt_size: %u\n",
+ le32_to_cpu(gfx_hdr->ucode_feature_version),
+ le32_to_cpu(gfx_hdr->jt_offset),
+ le32_to_cpu(gfx_hdr->jt_size));
} else {
DRM_ERROR("Unknown GFX ucode version: %u.%u\n", version_major, version_minor);
}
@@ -132,82 +147,88 @@ void amdgpu_ucode_print_rlc_hdr(const struct common_firmware_header *hdr)
const struct rlc_firmware_header_v1_0 *rlc_hdr =
container_of(hdr, struct rlc_firmware_header_v1_0, header);

- DRM_DEBUG("ucode_feature_version: %u\n",
- le32_to_cpu(rlc_hdr->ucode_feature_version));
- DRM_DEBUG("save_and_restore_offset: %u\n",
- le32_to_cpu(rlc_hdr->save_and_restore_offset));
- DRM_DEBUG("clear_state_descriptor_offset: %u\n",
- le32_to_cpu(rlc_hdr->clear_state_descriptor_offset));
- DRM_DEBUG("avail_scratch_ram_locations: %u\n",
- le32_to_cpu(rlc_hdr->avail_scratch_ram_locations));
- DRM_DEBUG("master_pkt_description_offset: %u\n",
+ DRM_DEBUG("ucode_feature_version: %u\n"
+ "save_and_restore_offset: %u\n"
+ "clear_state_descriptor_offset: %u\n"
+ "avail_scratch_ram_locations: %u\n"
+ "master_pkt_description_offset: %u\n",
+ le32_to_cpu(rlc_hdr->ucode_feature_version),
+ le32_to_cpu(rlc_hdr->save_and_restore_offset),
+ le32_to_cpu(rlc_hdr->clear_state_descriptor_offset),
+ le32_to_cpu(rlc_hdr->avail_scratch_ram_locations),
le32_to_cpu(rlc_hdr->master_pkt_description_offset));
+
} else if (version_major == 2) {
const struct rlc_firmware_header_v2_0 *rlc_hdr =
container_of(hdr, struct rlc_firmware_header_v2_0, header);

- DRM_DEBUG("ucode_feature_version: %u\n",
- le32_to_cpu(rlc_hdr->ucode_feature_version));
- DRM_DEBUG("jt_offset: %u\n", le32_to_cpu(rlc_hdr->jt_offset));
- DRM_DEBUG("jt_size: %u\n", le32_to_cpu(rlc_hdr->jt_size));
- DRM_DEBUG("save_and_restore_offset: %u\n",
- le32_to_cpu(rlc_hdr->save_and_restore_offset));
- DRM_DEBUG("clear_state_descriptor_offset: %u\n",
- le32_to_cpu(rlc_hdr->clear_state_descriptor_offset));
- DRM_DEBUG("avail_scratch_ram_locations: %u\n",
- le32_to_cpu(rlc_hdr->avail_scratch_ram_locations));
- DRM_DEBUG("reg_restore_list_size: %u\n",
- le32_to_cpu(rlc_hdr->reg_restore_list_size));
- DRM_DEBUG("reg_list_format_start: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_format_start));
- DRM_DEBUG("reg_list_format_separate_start: %u\n",
+ DRM_DEBUG("ucode_feature_version: %u\n"
+ "jt_offset: %u\n"
+ "jt_size: %u\n"
+ "save_and_restore_offset: %u\n"
+ "clear_state_descriptor_offset: %u\n"
+ "avail_scratch_ram_locations: %u\n"
+ "reg_restore_list_size: %u\n"
+ "reg_list_format_start: %u\n"
+ "reg_list_format_separate_start: %u\n",
+ le32_to_cpu(rlc_hdr->ucode_feature_version),
+ le32_to_cpu(rlc_hdr->jt_offset),
+ le32_to_cpu(rlc_hdr->jt_size),
+ le32_to_cpu(rlc_hdr->save_and_restore_offset),
+ le32_to_cpu(rlc_hdr->clear_state_descriptor_offset),
+ le32_to_cpu(rlc_hdr->avail_scratch_ram_locations),
+ le32_to_cpu(rlc_hdr->reg_restore_list_size),
+ le32_to_cpu(rlc_hdr->reg_list_format_start),
le32_to_cpu(rlc_hdr->reg_list_format_separate_start));
- DRM_DEBUG("starting_offsets_start: %u\n",
- le32_to_cpu(rlc_hdr->starting_offsets_start));
- DRM_DEBUG("reg_list_format_size_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_format_size_bytes));
- DRM_DEBUG("reg_list_format_array_offset_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_format_array_offset_bytes));
- DRM_DEBUG("reg_list_size_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_size_bytes));
- DRM_DEBUG("reg_list_array_offset_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_array_offset_bytes));
- DRM_DEBUG("reg_list_format_separate_size_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_format_separate_size_bytes));
- DRM_DEBUG("reg_list_format_separate_array_offset_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_format_separate_array_offset_bytes));
- DRM_DEBUG("reg_list_separate_size_bytes: %u\n",
- le32_to_cpu(rlc_hdr->reg_list_separate_size_bytes));
- DRM_DEBUG("reg_list_separate_array_offset_bytes: %u\n",
+
+ DRM_DEBUG("starting_offsets_start: %u\n"
+ "reg_list_format_size_bytes: %u\n"
+ "reg_list_format_array_offset_bytes: %u\n"
+ "reg_list_size_bytes: %u\n"
+ "reg_list_array_offset_bytes: %u\n"
+ "reg_list_format_separate_size_bytes: %u\n"
+ "reg_list_format_separate_array_offset_bytes: %u\n"
+ "reg_list_separate_size_bytes: %u\n"
+ "reg_list_separate_array_offset_bytes: %u\n",
+ le32_to_cpu(rlc_hdr->starting_offsets_start),
+ le32_to_cpu(rlc_hdr->reg_list_format_size_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_format_array_offset_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_size_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_array_offset_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_format_separate_size_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_format_separate_array_offset_bytes),
+ le32_to_cpu(rlc_hdr->reg_list_separate_size_bytes),
le32_to_cpu(rlc_hdr->reg_list_separate_array_offset_bytes));
+
if (version_minor == 1) {
const struct rlc_firmware_header_v2_1 *v2_1 =
container_of(rlc_hdr, struct rlc_firmware_header_v2_1, v2_0);
- DRM_DEBUG("reg_list_format_direct_reg_list_length: %u\n",
- le32_to_cpu(v2_1->reg_list_format_direct_reg_list_length));
- DRM_DEBUG("save_restore_list_cntl_ucode_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_cntl_ucode_ver));
- DRM_DEBUG("save_restore_list_cntl_feature_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_cntl_feature_ver));
- DRM_DEBUG("save_restore_list_cntl_size_bytes %u\n",
- le32_to_cpu(v2_1->save_restore_list_cntl_size_bytes));
- DRM_DEBUG("save_restore_list_cntl_offset_bytes: %u\n",
- le32_to_cpu(v2_1->save_restore_list_cntl_offset_bytes));
- DRM_DEBUG("save_restore_list_gpm_ucode_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_gpm_ucode_ver));
- DRM_DEBUG("save_restore_list_gpm_feature_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_gpm_feature_ver));
- DRM_DEBUG("save_restore_list_gpm_size_bytes %u\n",
- le32_to_cpu(v2_1->save_restore_list_gpm_size_bytes));
- DRM_DEBUG("save_restore_list_gpm_offset_bytes: %u\n",
- le32_to_cpu(v2_1->save_restore_list_gpm_offset_bytes));
- DRM_DEBUG("save_restore_list_srm_ucode_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_srm_ucode_ver));
- DRM_DEBUG("save_restore_list_srm_feature_ver: %u\n",
- le32_to_cpu(v2_1->save_restore_list_srm_feature_ver));
- DRM_DEBUG("save_restore_list_srm_size_bytes %u\n",
- le32_to_cpu(v2_1->save_restore_list_srm_size_bytes));
- DRM_DEBUG("save_restore_list_srm_offset_bytes: %u\n",
+
+ DRM_DEBUG("reg_list_format_direct_reg_list_length: %u\n"
+ "save_restore_list_cntl_ucode_ver: %u\n"
+ "save_restore_list_cntl_feature_ver: %u\n"
+ "save_restore_list_cntl_size_bytes %u\n"
+ "save_restore_list_cntl_offset_bytes: %u\n"
+ "save_restore_list_gpm_ucode_ver: %u\n"
+ "save_restore_list_gpm_feature_ver: %u\n"
+ "save_restore_list_gpm_size_bytes %u\n"
+ "save_restore_list_gpm_offset_bytes: %u\n"
+ "save_restore_list_srm_ucode_ver: %u\n"
+ "save_restore_list_srm_feature_ver: %u\n"
+ "save_restore_list_srm_size_bytes %u\n"
+ "save_restore_list_srm_offset_bytes: %u\n",
+ le32_to_cpu(v2_1->reg_list_format_direct_reg_list_length),
+ le32_to_cpu(v2_1->save_restore_list_cntl_ucode_ver),
+ le32_to_cpu(v2_1->save_restore_list_cntl_feature_ver),
+ le32_to_cpu(v2_1->save_restore_list_cntl_size_bytes),
+ le32_to_cpu(v2_1->save_restore_list_cntl_offset_bytes),
+ le32_to_cpu(v2_1->save_restore_list_gpm_ucode_ver),
+ le32_to_cpu(v2_1->save_restore_list_gpm_feature_ver),
+ le32_to_cpu(v2_1->save_restore_list_gpm_size_bytes),
+ le32_to_cpu(v2_1->save_restore_list_gpm_offset_bytes),
+ le32_to_cpu(v2_1->save_restore_list_srm_ucode_ver),
+ le32_to_cpu(v2_1->save_restore_list_srm_feature_ver),
+ le32_to_cpu(v2_1->save_restore_list_srm_size_bytes),
le32_to_cpu(v2_1->save_restore_list_srm_offset_bytes));
}
} else {
@@ -227,12 +248,14 @@ void amdgpu_ucode_print_sdma_hdr(const struct common_firmware_header *hdr)
const struct sdma_firmware_header_v1_0 *sdma_hdr =
container_of(hdr, struct sdma_firmware_header_v1_0, header);

- DRM_DEBUG("ucode_feature_version: %u\n",
- le32_to_cpu(sdma_hdr->ucode_feature_version));
- DRM_DEBUG("ucode_change_version: %u\n",
- le32_to_cpu(sdma_hdr->ucode_change_version));
- DRM_DEBUG("jt_offset: %u\n", le32_to_cpu(sdma_hdr->jt_offset));
- DRM_DEBUG("jt_size: %u\n", le32_to_cpu(sdma_hdr->jt_size));
+ DRM_DEBUG("ucode_feature_version: %u\n"
+ "ucode_change_version: %u\n"
+ "jt_offset: %u\n"
+ "jt_size: %u\n",
+ le32_to_cpu(sdma_hdr->ucode_feature_version),
+ le32_to_cpu(sdma_hdr->ucode_change_version),
+ le32_to_cpu(sdma_hdr->jt_offset),
+ le32_to_cpu(sdma_hdr->jt_size));
if (version_minor >= 1) {
const struct sdma_firmware_header_v1_1 *sdma_v1_1_hdr =
container_of(sdma_hdr, struct sdma_firmware_header_v1_1, v1_0);
@@ -256,36 +279,36 @@ void amdgpu_ucode_print_psp_hdr(const struct common_firmware_header *hdr)
const struct psp_firmware_header_v1_0 *psp_hdr =
container_of(hdr, struct psp_firmware_header_v1_0, header);

- DRM_DEBUG("ucode_feature_version: %u\n",
- le32_to_cpu(psp_hdr->sos.fw_version));
- DRM_DEBUG("sos_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr->sos.offset_bytes));
- DRM_DEBUG("sos_size_bytes: %u\n",
+ DRM_DEBUG("ucode_feature_version: %u\n"
+ "sos_offset_bytes: %u\n"
+ "sos_size_bytes: %u\n",
+ le32_to_cpu(psp_hdr->sos.fw_version),
+ le32_to_cpu(psp_hdr->sos.offset_bytes),
le32_to_cpu(psp_hdr->sos.size_bytes));
if (version_minor == 1) {
const struct psp_firmware_header_v1_1 *psp_hdr_v1_1 =
container_of(psp_hdr, struct psp_firmware_header_v1_1, v1_0);
- DRM_DEBUG("toc_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_1->toc.fw_version));
- DRM_DEBUG("toc_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_1->toc.offset_bytes));
- DRM_DEBUG("toc_size_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_1->toc.size_bytes));
- DRM_DEBUG("kdb_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_1->kdb.fw_version));
- DRM_DEBUG("kdb_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_1->kdb.offset_bytes));
- DRM_DEBUG("kdb_size_bytes: %u\n",
+ DRM_DEBUG("toc_header_version: %u\n"
+ "toc_offset_bytes: %u\n"
+ "toc_size_bytes: %u\n"
+ "kdb_header_version: %u\n"
+ "kdb_offset_bytes: %u\n"
+ "kdb_size_bytes: %u\n",
+ le32_to_cpu(psp_hdr_v1_1->toc.fw_version),
+ le32_to_cpu(psp_hdr_v1_1->toc.offset_bytes),
+ le32_to_cpu(psp_hdr_v1_1->toc.size_bytes),
+ le32_to_cpu(psp_hdr_v1_1->kdb.fw_version),
+ le32_to_cpu(psp_hdr_v1_1->kdb.offset_bytes),
le32_to_cpu(psp_hdr_v1_1->kdb.size_bytes));
}
if (version_minor == 2) {
const struct psp_firmware_header_v1_2 *psp_hdr_v1_2 =
container_of(psp_hdr, struct psp_firmware_header_v1_2, v1_0);
- DRM_DEBUG("kdb_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_2->kdb.fw_version));
- DRM_DEBUG("kdb_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_2->kdb.offset_bytes));
- DRM_DEBUG("kdb_size_bytes: %u\n",
+ DRM_DEBUG("kdb_header_version: %u\n"
+ "kdb_offset_bytes: %u\n"
+ "kdb_size_bytes: %u\n",
+ le32_to_cpu(psp_hdr_v1_2->kdb.fw_version),
+ le32_to_cpu(psp_hdr_v1_2->kdb.offset_bytes),
le32_to_cpu(psp_hdr_v1_2->kdb.size_bytes));
}
if (version_minor == 3) {
@@ -293,23 +316,23 @@ void amdgpu_ucode_print_psp_hdr(const struct common_firmware_header *hdr)
container_of(psp_hdr, struct psp_firmware_header_v1_1, v1_0);
const struct psp_firmware_header_v1_3 *psp_hdr_v1_3 =
container_of(psp_hdr_v1_1, struct psp_firmware_header_v1_3, v1_1);
- DRM_DEBUG("toc_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.toc.fw_version));
- DRM_DEBUG("toc_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.toc.offset_bytes));
- DRM_DEBUG("toc_size_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.toc.size_bytes));
- DRM_DEBUG("kdb_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.fw_version));
- DRM_DEBUG("kdb_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.offset_bytes));
- DRM_DEBUG("kdb_size_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.size_bytes));
- DRM_DEBUG("spl_header_version: %u\n",
- le32_to_cpu(psp_hdr_v1_3->spl.fw_version));
- DRM_DEBUG("spl_offset_bytes: %u\n",
- le32_to_cpu(psp_hdr_v1_3->spl.offset_bytes));
- DRM_DEBUG("spl_size_bytes: %u\n",
+ DRM_DEBUG("toc_header_version: %u\n"
+ "toc_offset_bytes: %u\n"
+ "toc_size_bytes: %u\n"
+ "kdb_header_version: %u\n"
+ "kdb_offset_bytes: %u\n"
+ "kdb_size_bytes: %u\n"
+ "spl_header_version: %u\n"
+ "spl_offset_bytes: %u\n"
+ "spl_size_bytes: %u\n",
+ le32_to_cpu(psp_hdr_v1_3->v1_1.toc.fw_version),
+ le32_to_cpu(psp_hdr_v1_3->v1_1.toc.offset_bytes),
+ le32_to_cpu(psp_hdr_v1_3->v1_1.toc.size_bytes),
+ le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.fw_version),
+ le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.offset_bytes),
+ le32_to_cpu(psp_hdr_v1_3->v1_1.kdb.size_bytes),
+ le32_to_cpu(psp_hdr_v1_3->spl.fw_version),
+ le32_to_cpu(psp_hdr_v1_3->spl.offset_bytes),
le32_to_cpu(psp_hdr_v1_3->spl.size_bytes));
}
} else {
@@ -330,9 +353,9 @@ void amdgpu_ucode_print_gpu_info_hdr(const struct common_firmware_header *hdr)
const struct gpu_info_firmware_header_v1_0 *gpu_info_hdr =
container_of(hdr, struct gpu_info_firmware_header_v1_0, header);

- DRM_DEBUG("version_major: %u\n",
- le16_to_cpu(gpu_info_hdr->version_major));
- DRM_DEBUG("version_minor: %u\n",
+ DRM_DEBUG("version_major: %u\n"
+ "version_minor: %u\n",
+ le16_to_cpu(gpu_info_hdr->version_major),
le16_to_cpu(gpu_info_hdr->version_minor));
} else {
DRM_ERROR("Unknown gpu_info ucode version: %u.%u\n", version_major, version_minor);
--
2.31.1

2021-08-13 15:27:02

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 3/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks

DEFINE_DYNAMIC_DEBUG_CATEGORIES(name, var, bitmap_desc, @bit_descs)
allows users to define a drm.debug style (bitmap) sysfs interface, and
to specify the desired mapping from bits[0-N] to the format-prefix'd
pr_debug()s to be controlled.

DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
"i915/gvt bitmap desc",
/**
* search-prefixes, passed to dd-exec_queries
* defines bits 0-N in order.
* leading ^ is tacitly inserted (by callback currently)
* trailing space used here excludes subcats.
* helper macro needs more work
* macro to autogen ++$i, 0x%x$i ?
*/
_DD_cat_("gvt:cmd: "),
_DD_cat_("gvt:core: "),
_DD_cat_("gvt:dpy: "),
_DD_cat_("gvt:el: "),
_DD_cat_("gvt:irq: "),
_DD_cat_("gvt:mm: "),
_DD_cat_("gvt:mmio: "),
_DD_cat_("gvt:render: "),
_DD_cat_("gvt:sched: "));

dynamic_debug.c: add 3 new elements:

- int param_set_dyndbg()
- int param_get_dyndbg()
- struct kernel_param_ops param_ops_dyndbg

Following the model of kernel/params.c STANDARD_PARAM_DEFS, All 3 are
non-static and exported.

dynamic_debug.h:

Add DEFINE_DYNAMIC_DEBUG_CATEGORIES() described above, and a do-nothing stub.

Note that it also calls MODULE_PARM_DESC for the user, but expects the
user to catenate all the bit-descriptions together (as is done in
drm.debug), and in the following uses in amdgpu, i915.

This in the hope that someone can offer an auto-incrementing
label-generating macro, producing "\tbit-4 0x10\t" etc, and can show
how to apply it to __VA_ARGS__.

Also extern the struct kernel_param param_ops_dyndbg symbol, as is
done in moduleparams.h for all the STANDARD params.

USAGE NOTES:

Using dyndbg to query on "format ^$prefix" requires that the prefix be
present in the compiled-in format string; where run-time prefixing is
used, that format would be "%s...", which is not usefully selectable.

Adding structural query terms (func,file,lineno) could help (module is
already done), but DEFINE_DYNAMIC_DEBUG_CATEGORIES can't do that now,
adding it needs a better reason imo.

Dyndbg is completely agnostic wrt the categorization scheme used, to
play well with any prefix convention already in use. Ad-hoc
categories and sub-categories are implicitly allowed, author
discipline and review is expected.

Here are some examples:

"1","2","3" 2 doesnt imply 1.
otherwize, sorta like printk levels
"1:","2:","3:" are better, avoiding [1-9]\d+ ambiguity
"hi:","mid:","low:" are reasonable, and imply independence
"todo:","rfc:" might be handy
"A:".."Z:" uhm, yeah

Hierarchical classes/categories are natural:

"drm:<CAT>:" is used in later commit
"drm:<CAT>:<SUB>:" is a natural extension.
"drm:atomic:fail:" has been proposed, sounds directly useful

Some properties of a hierarchical category deserve explication:

Trailing spaces matter !

With 1..3-space ("drm: ", "drm:atomic: ", "drm:atomic:fail: "), the
":" doesnt terminate the search-space, the trailing space does.
So a "drm:" search specification will match all DRM categories &
subcategories, and will not be useful in an interface where all
categories are controlled together. That said, "drm:atomic:" &
"drm:atomic: " are different, and both are useful in cases.

Ad-Hoc sub-categories:

These have a caveat wrt wrapper macros adding prefixes like
"drm:atomic: "; the trailing space in the prefix means that
drm_dbg("fail: ...") renders as "drm:atomic: fail: ", which obviously
isn't ideal wrt clear and simple bitmaps.

A possible solution is to have a FOO_() version of every FOO() macro
which (anti-mnemonically) elides the trailing space, which is normally
inserted by a modified FOO(). Doing this would enforce a policy
decision that "debug categories will be space terminated", with an
pressure-relief valve.

Summarizing:

- "drm:kms: " & "drm:kms:" are different
- "drm:kms" also different - includes drm:kms2:
- "drm:kms:\t" also different
- "drm:kms:*" doesnt work, no wildcard on format atm.

Order matters in DEFINE_DYNAMIC_DEBUG_CATEGORIES(... @bit_descs)

@bit_descs (array) position determines the bit mapping to the prefix,
so to keep a stable map, new categories or 3rd level categories must
be added to the end.

Since bits are/will-stay applied 0-N, the later bits can countermand
the earlier ones, but its tricky - consider;

DD_CATs(... "drm:atomic:", ""drm:atomic:fail:" ) // misleading

The 1st search-term is misleading, because it includes (modifies)
subcategories, but then 2nd overrides it. So don't do that.

There is still plenty of bikeshedding to do.

---
v4+:

. rename to DEFINE_DYNAMIC_DEBUG_CATEGORIES from DEFINE_DYNDBG_BITMAP
. in query, replace hardcoded "i915" w kp->mod->name
. static inline the stubs
. const *str in structs, const array. -Emil
. dyndbg: add do-nothing DEFINE_DYNAMIC_DEBUG_CATEGORIES if !DD_CORE
. call MOD_PARM_DESC(name, "$desc") for users
. simplify callback, remove bit-change detection
. config errs reported by <[email protected]>

ddh-helpers

Signed-off-by: Jim Cromie <[email protected]>
---
include/linux/dynamic_debug.h | 50 ++++++++++++++++++++++++++++
lib/dynamic_debug.c | 62 ++++++++++++++++++++++++++++++++++-
2 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index dce631e678dd..42cfb37d4870 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -52,6 +52,7 @@ struct _ddebug {
} __attribute__((aligned(8)));


+struct kernel_param;

#if defined(CONFIG_DYNAMIC_DEBUG_CORE)

@@ -181,6 +182,9 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
KERN_DEBUG, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii)

+int param_set_dyndbg(const char *instr, const struct kernel_param *kp);
+int param_get_dyndbg(char *buffer, const struct kernel_param *kp);
+
#else /* !CONFIG_DYNAMIC_DEBUG_CORE */

#include <linux/string.h>
@@ -227,6 +231,52 @@ static inline int dynamic_debug_exec_queries(const char *query, const char *modn
return 0;
}

+static inline int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
+{ return 0; }
+static inline int param_get_dyndbg(char *buffer, const struct kernel_param *kp)
+{ return 0; }
+
#endif /* !CONFIG_DYNAMIC_DEBUG_CORE */

+struct dyndbg_bitdesc {
+ /* bitpos is inferred from index in containing array */
+ const char *prefix;
+ const char *help;
+};
+
+#if defined(CONFIG_DYNAMIC_DEBUG) || \
+ (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
+/**
+ * DEFINE_DYNAMIC_DEBUG_CATEGORIES() - define debug categories, bitmap, sysfs-knob
+ * @fsname: parameter basename under /sys
+ * @var: C-identifier holding state
+ * @_desc: string summarizing the controls provided
+ * @...: list of struct dyndbg_bitdesc initializations
+ *
+ * Defines /sys/modules/$modname/parameters/@fsname, and @bit_descs,
+ * which maps bits 0-N to categories of pr_debugs to be controlled.
+ * This is effectively write only, because controlled callsites can be
+ * further modified via >control.
+ *
+ * Also calls MODULE_PARM_DESC(fsname, _desc), with the intent to
+ * generate the bit_legend and apply it to the given bit_descs
+ */
+#define DEFINE_DYNAMIC_DEBUG_CATEGORIES(fsname, var, _desc, ...) \
+ MODULE_PARM_DESC(fsname, _desc); \
+ static struct dyndbg_bitdesc const dyndbg_cats_##fsname[] = \
+ { __VA_ARGS__, { NULL, NULL } }; \
+ module_param_cbd(fsname, &param_ops_dyndbg, &var, 0644, \
+ &dyndbg_cats_##fsname);
+
+#define _DD_cat_(pfx) { .prefix = pfx, .help = "help for " pfx }
+#define _DD_cat_help_(pfx) "\t " pfx "\t- help for " pfx "\n"
+
+extern const struct kernel_param_ops param_ops_dyndbg;
+#else
+#define DEFINE_DYNAMIC_DEBUG_CATEGORIES(fsname, var, bitmap_desc, ...) \
+ MODULE_PARM_DESC(fsname, "auto: " bitmap_desc);
+#define _DD_cat_(pfx)
+#define _DD_cat_help_(pfx)
+#endif
+
#endif
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index cb5abb42c16a..6bc645a663e7 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -529,7 +529,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
if (!query || !*query || *query == '#')
continue;

- vpr_info("query %d: \"%s\"\n", i, query);
+ vpr_info("query %d: \"%s\" %s\n", i, query, (modname) ? modname : "");

rc = ddebug_exec_query(query, modname);
if (rc < 0) {
@@ -1154,3 +1154,63 @@ early_initcall(dynamic_debug_init);

/* Debugfs setup must be done later */
fs_initcall(dynamic_debug_init_control);
+
+#include <linux/moduleparam.h>
+
+#define OUR_QUERY_SIZE 128 /* typically need <40 */
+
+/**
+ * param_set_dyndbg() - drm.debug style bitmap to format-prefix categories
+ * @instr: string echo>d to sysfs
+ * @kp: struct kernel_param* ->data has bitmap
+ * Exported to support DEFINE_DYNAMIC_DEBUG_CATEGORIES
+ */
+int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
+{
+ unsigned long inbits;
+ int rc, i, chgct = 0, totct = 0;
+ char query[OUR_QUERY_SIZE];
+ struct dyndbg_bitdesc *bitmap = (struct dyndbg_bitdesc *) kp->data;
+
+ rc = kstrtoul(instr, 0, &inbits);
+ if (rc) {
+ pr_err("set_dyndbg: failed\n");
+ return -EINVAL;
+ }
+ vpr_info("set_dyndbg: input 0x%lx\n", inbits);
+
+ for (i = 0; !!bitmap[i].prefix; i++) {
+
+ sprintf(query, "format '^%s' %cp", bitmap[i].prefix,
+ test_bit(i, &inbits) ? '+' : '-');
+
+ chgct = dynamic_debug_exec_queries(query, kp->mod->name);
+
+ v2pr_info("bit-%d: %d changes by '%s'\n", i, chgct, query);
+ totct += chgct;
+ }
+ vpr_info("total changes: %d\n", totct);
+ return 0;
+}
+EXPORT_SYMBOL(param_set_dyndbg);
+
+/**
+ * param_get_dyndbg() - drm.debug style bitmap to format-prefix categories
+ * @buffer: string returned to user via sysfs
+ * @kp: struct kernel_param*
+ * Exported to support DEFINE_DYNAMIC_DEBUG_CATEGORIES interfaces, not
+ * useful; pr_debugs may be altered after setting via >control
+ */
+int param_get_dyndbg(char *buffer, const struct kernel_param *kp)
+{
+ return scnprintf(buffer, PAGE_SIZE, "%u\n",
+ *((unsigned int *)kp->arg));
+}
+EXPORT_SYMBOL(param_get_dyndbg);
+
+const struct kernel_param_ops param_ops_dyndbg = {
+ .set = param_set_dyndbg,
+ .get = param_get_dyndbg,
+};
+/* support DEFINE_DYNAMIC_DEBUG_CATEGORIES users */
+EXPORT_SYMBOL(param_ops_dyndbg);
--
2.31.1

2021-08-13 15:28:31

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 2/9] moduleparam: add data member to struct kernel_param

Add a const void* data member to the struct, to allow attaching
private data that will be used soon by a setter method (via kp->data)
to perform more elaborate actions.

To attach the data at compile time, add new macros:

module_param_cbd() derives from module_param_cb(), adding data param,
and latter is redefined to use former.

It calls __module_param_call_wdata(), which accepts a new data param
and inits .data with it. Re-define __module_param_call() to use it.

Use of this new data member will be rare, it might be worth redoing
this as a separate/sub-type to de-bloat the base case.

---
v4+:
. const void* data - <[email protected]>

Signed-off-by: Jim Cromie <[email protected]>
---
include/linux/moduleparam.h | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index eed280fae433..878387e0b2d9 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -78,6 +78,7 @@ struct kernel_param {
const struct kparam_string *str;
const struct kparam_array *arr;
};
+ const void *data;
};

extern const struct kernel_param __start___param[], __stop___param[];
@@ -175,6 +176,9 @@ struct kparam_array
#define module_param_cb(name, ops, arg, perm) \
__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)

+#define module_param_cbd(name, ops, arg, perm, data) \
+ __module_param_call_wdata(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0, data)
+
#define module_param_cb_unsafe(name, ops, arg, perm) \
__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
KERNEL_PARAM_FL_UNSAFE)
@@ -284,14 +288,17 @@ struct kparam_array

/* This is the fundamental function for registering boot/module
parameters. */
-#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
+#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
+ __module_param_call_wdata(prefix, name, ops, arg, perm, level, flags, NULL)
+
+#define __module_param_call_wdata(prefix, name, ops, arg, perm, level, flags, data) \
/* Default value instead of permissions? */ \
static const char __param_str_##name[] = prefix #name; \
static struct kernel_param __moduleparam_const __param_##name \
__used __section("__param") \
__aligned(__alignof__(struct kernel_param)) \
= { __param_str_##name, THIS_MODULE, ops, \
- VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } }
+ VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg }, data }

/* Obsolete - use module_param_cb() */
#define module_param_call(name, _set, _get, arg, perm) \
--
2.31.1

2021-08-13 15:29:12

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 9/9] dyndbg: RFC add tracer facility RFC

Sean Paul [email protected] proposed, in
https://patchwork.freedesktop.org/series/78133/
drm/trace: Mirror DRM debug logs to tracefs

That patchset's goal is to be able to duplicate the debug stream to a
tracing destination, by splitting drm_debug_enabled() into syslog &
trace flavors, and enabling them separately. That clashes rather
deeply with this patchset's goal; to avoid drm_debug_enabled() using
dyndbg.

Instead, this puts the print-to-trace decision in dyndbg, after the
is-it-enabled test (which is a noop), so it has near zero additional
cost (other than memory increase); the print-to-trace test is only
done on enabled callsites.

The basic elements:

- add a new struct _ddebug member: (*tracer)(char *format, ...)
- add a new T flag to enable tracer
- adjust the static-key-enable/disable condition for (p|T)
- if (p) before printk, since T enables too.
- if (T) call tracer if its true

= int dynamic_debug_register_tracer(query, modname, tracer);
= int dynamic_debug_unregister_tracer(query, modname, cookie);

This new interface lets clients set/unset a tracer function on each
callsite matching the query, for example: "drm:atomic:fail:".

Clients are expected to unregister the same callsites they register (a
cookie), allowing protection of each client's dyndbg-state setup
against overwrites by others.

Intended Behavior: (things are in flux, RFC)

- register sets empty slot, doesnt overwrite
the query selects callsites, and sets +T (grammar requires +-action)

- register allows same-tracer over-set wo warn
2nd register can then enable superset, subset, disjoint set

- unregister clears slot if it matches cookie/tracer
query selects set, -T (as tested)
tolerates over-clears

- dd-exec-queries(+/-T) can modify the enablements
not sure its needed, but it falls out..

The code is currently in-line in ddebug_change(), to be moved to
separate fn, rc determines flow, may also veto/alter changes by
altering flag-settings - tbd.

TBD: Im not sure what happens when exec-queries(+T) hits a site wo a
tracer (silence I think. maybe not ideal).

internal call-chain gets a tracer param:
New arg:
public: dynamic_debug_exec_queries
ro-string copy moved ...
1 ddebug_exec_queries tracer=NULL
... to here
2 ddebug_exec_query tracer=NULL

call-chain gets (re)used: with !NULL

public: dynamic_debug_register_tracer tracer=client's
w ro-string
1 ddebug_exec_queries tracer
...

SELFTEST: test_dynamic_debug.ko:

Uses the tracer facility to do a selftest:

- A custom tracer counts the number of calls (of T-enabled pr_debugs),
- do_debugging(x) calls a set of categorized pr_debugs x times

- test registers the tracer on the function,
then iteratively:
manipulates dyndbg states via query-cmds
runs do_debugging()
counts enabled callsite executions
reports mismatches

- modprobe test_dynamic_debug use_bad_tracer=1
attaches a bad/recursive tracer
Bad Things Happen.
has thrown me interesting panics.

NOTES:

This needs more work. RFC.

ERRORS (or WARNINGS):

It should be an error to +T a callsite which has no aux_print set (ie
already registered with a query that selected that callsite). This
tacitly enforces registration.

Then +T,-T can toggle those aux_print callsites (or subsets of them)
to tailor the debug-stream for the purpose. Controlling flow is the
best work limiter.

---
v4+: (this patch sent after (on top of) v4)

. fix "too many arguments to function", and name the args:
int (*aux_print)(const char *fmt, char *prefix, char *label, void *);
prefix : is a slot for dynamic_emit_prefix, or for custom buffer insert
label : for builtin-caller used by drm-trace-print
void* : vaf, add type constraint later.

. fix printk (to syslog) needs if (+p), since +T also enables
. add prototypes for un/register_aux_print
. change iface names: s/aux_print/tracer/
. also s/trace_print/tracer/
. struct va_format *vaf - tighten further ?

Signed-off-by: Jim Cromie <[email protected]>
---
include/linux/dynamic_debug.h | 32 ++++-
lib/Kconfig.debug | 10 ++
lib/Makefile | 1 +
lib/dynamic_debug.c | 109 +++++++++++----
lib/test_dynamic_debug.c | 247 ++++++++++++++++++++++++++++++++++
5 files changed, 372 insertions(+), 27 deletions(-)
create mode 100644 lib/test_dynamic_debug.c

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 42cfb37d4870..cbcb1c94cec3 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -20,6 +20,7 @@ struct _ddebug {
const char *function;
const char *filename;
const char *format;
+ int (*tracer)(const char *fmt, char *prefix, char *label, struct va_format *vaf);
unsigned int lineno:18;
/*
* The flags field controls the behaviour at the callsite.
@@ -27,7 +28,11 @@ struct _ddebug {
* writes commands to <debugfs>/dynamic_debug/control
*/
#define _DPRINTK_FLAGS_NONE 0
-#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
+#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message */
+#define _DPRINTK_FLAGS_PRINT_TRACE (1<<5) /* call (*tracer) */
+
+#define _DPRINTK_ENABLED (_DPRINTK_FLAGS_PRINT | _DPRINTK_FLAGS_PRINT_TRACE)
+
#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
@@ -279,4 +284,29 @@ extern const struct kernel_param_ops param_ops_dyndbg;
#define _DD_cat_help_(pfx)
#endif

+/**
+ * dynamic_debug_register_tracer - register a "printer" function
+ * @query: query-command string to select callsites getting the function
+ * @tracer: &vprintf-ish accepting 3 char* ptrs & a vaf
+ *
+ * Attach a printer function to callsites selected by query.
+ * If another printer is already attached, warn and skip, applying the
+ * rest of the query. This protects existing setups, while allowing
+ * maximal coexistence of (mostly) non-competing listeners. RFC.
+ */
+int dynamic_debug_register_tracer(const char *query, const char *mod,
+ int (*tracer) (const char *fmt, char *prefix, char *label, struct va_format *vaf));
+/**
+ * dynamic_debug_unregister_tracer - unregister your "printer" function
+ * @query: query-command string to select callsites to reset
+ * @cookie: reserved to validate unregisters against pirates
+ *
+ * Detach this printer function (@cookie) from callsites selected by
+ * the query, when @cookie == callsite. This protects existing
+ * setups, while allowing maximal coexistence of (mostly)
+ * non-competing listeners. RFC.
+ */
+int dynamic_debug_unregister_tracer(const char *query, const char *mod,
+ int (*cookie) (const char *fmt, char *prefix, char *label, struct va_format *vaf));
+
#endif
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5ddd575159fb..5038f81d3fc6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2486,6 +2486,16 @@ config TEST_STATIC_KEYS

If unsure, say N.

+config TEST_DYNAMIC_DEBUG
+ tristate "Test DYNAMIC_DEBUG"
+ depends on m
+ depends on DYNAMIC_DEBUG
+ help
+ Test the print_aux registration with a counting fn,
+ then test expected counts during the execution.
+
+ If unsure, say N.
+
config TEST_KMOD
tristate "kmod stress tester"
depends on m
diff --git a/lib/Makefile b/lib/Makefile
index 5efd1b435a37..01c3c76980ba 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o
obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
+obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
obj-$(CONFIG_TEST_PRINTF) += test_printf.o
obj-$(CONFIG_TEST_SCANF) += test_scanf.o
obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6bc645a663e7..9ba180976636 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -85,6 +85,7 @@ static inline const char *trim_prefix(const char *path)

static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_PRINT, 'p' },
+ { _DPRINTK_FLAGS_PRINT_TRACE, 'T' },
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
@@ -146,7 +147,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
* logs the changes. Takes ddebug_lock.
*/
static int ddebug_change(const struct ddebug_query *query,
- struct flag_settings *modifiers)
+ struct flag_settings *modifiers,
+ int (*tracer)(const char *, char *, char *, struct va_format *))
{
int i;
struct ddebug_table *dt;
@@ -205,11 +207,43 @@ static int ddebug_change(const struct ddebug_query *query,
newflags = (dp->flags & modifiers->mask) | modifiers->flags;
if (newflags == dp->flags)
continue;
+
+ /* handle T flag */
+ if (newflags & _DPRINTK_FLAGS_PRINT_TRACE) {
+ if (!tracer)
+ v2pr_info("tracer enable\n");
+ else {
+ /* register attempt */
+ if (!dp->tracer) {
+ v2pr_info("register tracer\n");
+ dp->tracer = tracer;
+ }
+ else if (tracer == dp->tracer)
+ v2pr_info("tracer equal, ok\n");
+ else
+ pr_warn("tracer register error\n");
+ }
+ } else if (dp->flags & _DPRINTK_FLAGS_PRINT_TRACE) {
+ if (!tracer)
+ v2pr_info("ok: disabling\n");
+ else {
+ /* only unregister has a !!tracer */
+ if (!dp->tracer)
+ pr_warn("nok: tracer already unset\n");
+
+ else if (dp->tracer == tracer) {
+ v2pr_info("ok: cookie match, unregistering\n");
+ dp->tracer = NULL;
+ }
+ else
+ pr_warn("nok: tracer cookie match fail\n");
+ }
+ }
#ifdef CONFIG_JUMP_LABEL
- if (dp->flags & _DPRINTK_FLAGS_PRINT) {
- if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
+ if (dp->flags & _DPRINTK_ENABLED) {
+ if (!(modifiers->flags & _DPRINTK_ENABLED))
static_branch_disable(&dp->key.dd_key_true);
- } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
+ } else if (modifiers->flags & _DPRINTK_ENABLED)
static_branch_enable(&dp->key.dd_key_true);
#endif
dp->flags = newflags;
@@ -482,7 +516,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
return 0;
}

-static int ddebug_exec_query(char *query_string, const char *modname)
+static int ddebug_exec_query(char *query_string, const char *modname, void *tracer)
{
struct flag_settings modifiers = {};
struct ddebug_query query = {};
@@ -505,7 +539,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
return -EINVAL;
}
/* actually go and implement the change */
- nfound = ddebug_change(&query, &modifiers);
+ nfound = ddebug_change(&query, &modifiers, tracer);
vpr_info_dq(&query, nfound ? "applied" : "no-match");

return nfound;
@@ -515,10 +549,19 @@ static int ddebug_exec_query(char *query_string, const char *modname)
last error or number of matching callsites. Module name is either
in param (for boot arg) or perhaps in query string.
*/
-static int ddebug_exec_queries(char *query, const char *modname)
+static int ddebug_exec_queries(const char *query_in, const char *modname, void *tracer)
{
char *split;
int i, errs = 0, exitcode = 0, rc, nfound = 0;
+ char *query; /* writable copy of query_in */
+
+ if (!query_in) {
+ pr_err("non-null query/command string expected\n");
+ return -EINVAL;
+ }
+ query = kstrndup(query_in, PAGE_SIZE, GFP_KERNEL);
+ if (!query)
+ return -ENOMEM;

for (i = 0; query; query = split) {
split = strpbrk(query, ";\n");
@@ -531,7 +574,7 @@ static int ddebug_exec_queries(char *query, const char *modname)

vpr_info("query %d: \"%s\" %s\n", i, query, (modname) ? modname : "");

- rc = ddebug_exec_query(query, modname);
+ rc = ddebug_exec_query(query, modname, tracer);
if (rc < 0) {
errs++;
exitcode = rc;
@@ -540,6 +583,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
}
i++;
}
+ kfree(query);
vpr_info("processed %d queries, with %d matches, %d errs\n",
i, nfound, errs);

@@ -560,20 +604,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
*/
int dynamic_debug_exec_queries(const char *query, const char *modname)
{
- int rc;
- char *qry; /* writable copy of query */
-
- if (!query) {
- pr_err("non-null query/command string expected\n");
- return -EINVAL;
- }
- qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
- if (!qry)
- return -ENOMEM;
-
- rc = ddebug_exec_queries(qry, modname);
- kfree(qry);
- return rc;
+ return ddebug_exec_queries(query, modname, NULL);
}
EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);

@@ -637,8 +668,20 @@ void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
vaf.fmt = fmt;
vaf.va = &args;

- printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
+ if (descriptor->flags & _DPRINTK_ENABLED)
+ dynamic_emit_prefix(descriptor, buf);
+
+ if (descriptor->flags & _DPRINTK_FLAGS_PRINT)
+ printk(KERN_DEBUG "%s%pV", buf, &vaf);

+ if (descriptor->flags & _DPRINTK_FLAGS_PRINT_TRACE) {
+
+ if (descriptor->tracer) {
+ (*descriptor->tracer)("%s:%ps %pV", buf,
+ __builtin_return_address(0), &vaf);
+ }
+ /* else shouldnt matter, but maybe for consistency */
+ }
va_end(args);
}
EXPORT_SYMBOL(__dynamic_pr_debug);
@@ -783,7 +826,7 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
return PTR_ERR(tmpbuf);
vpr_info("read %d bytes from userspace\n", (int)len);

- ret = ddebug_exec_queries(tmpbuf, NULL);
+ ret = ddebug_exec_queries(tmpbuf, NULL, NULL);
kfree(tmpbuf);
if (ret < 0)
return ret;
@@ -989,7 +1032,7 @@ static int ddebug_dyndbg_param_cb(char *param, char *val,
if (strcmp(param, "dyndbg"))
return on_err; /* determined by caller */

- ddebug_exec_queries((val ? val : "+p"), modname);
+ ddebug_exec_queries((val ? val : "+p"), modname, NULL);

return 0; /* query failure shouldn't stop module load */
}
@@ -1124,7 +1167,7 @@ static int __init dynamic_debug_init(void)
/* apply ddebug_query boot param, dont unload tables on err */
if (ddebug_setup_string[0] != '\0') {
pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
- ret = ddebug_exec_queries(ddebug_setup_string, NULL);
+ ret = ddebug_exec_queries(ddebug_setup_string, NULL, NULL);
if (ret < 0)
pr_warn("Invalid ddebug boot param %s\n",
ddebug_setup_string);
@@ -1214,3 +1257,17 @@ const struct kernel_param_ops param_ops_dyndbg = {
};
/* support DEFINE_DYNAMIC_DEBUG_CATEGORIES users */
EXPORT_SYMBOL(param_ops_dyndbg);
+
+int dynamic_debug_register_tracer(const char *query, const char *mod,
+ int (*tracer) (const char *fmt, char *prefix, char *label, struct va_format *vaf))
+{
+ return ddebug_exec_queries(query, mod, tracer);
+}
+EXPORT_SYMBOL(dynamic_debug_register_tracer);
+
+int dynamic_debug_unregister_tracer(const char *query, const char *mod,
+ int (*tracer) (const char *fmt, char *prefix, char *label, struct va_format *vaf))
+{
+ return ddebug_exec_queries(query, mod, tracer);
+}
+EXPORT_SYMBOL(dynamic_debug_unregister_tracer);
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
new file mode 100644
index 000000000000..e837398bd885
--- /dev/null
+++ b/lib/test_dynamic_debug.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kernel module for testing dynamic_debug
+ *
+ * Authors:
+ * Jim Cromie <[email protected]>
+ */
+
+/*
+ * test-setup: use trace_print attachment interface as a test harness,
+ * define a custom trace_printer which counts invocations, and a
+ * pr_debug event generator function which calls a set of categorized
+ * pr_debugs.
+ * test-run: manipulate the pr_debug's enablement, run the event
+ * generator, and check for the expected side effects.
+ */
+
+#include <linux/module.h>
+
+static int __bad_tracer;
+
+static int trace_ct = 0;
+static int test_ct = 0;
+static int errors = 0;
+static int verbose = 0;
+
+
+module_param_named(use_bad_tracer, __bad_tracer, int, 0644);
+MODULE_PARM_DESC(use_bad_tracer,
+ "use broken tracer, recursing with pr_debug\n"
+ "\tonly works at modprobe time\n");
+
+static int (*my_tracer)(const char *decorator, char *prefix, char *label, struct va_format *vaf);
+
+static int good_tracer(const char *decorator, char *prefix, char *label, struct va_format *vaf)
+{
+ trace_ct++;
+ if (verbose)
+ pr_notice("my_tracer: %pV", vaf);
+ return 0;
+}
+
+static int bad_tracer(const char *decorator, char *prefix, char *label, struct va_format *vaf)
+{
+ /* dont try pr_debug, it recurses back here */
+ pr_debug("oops! recursion, crash?\n");
+ return 0;
+}
+
+static void pick_tracer(void)
+{
+ if (__bad_tracer)
+ my_tracer = bad_tracer;
+ else
+ my_tracer = good_tracer;
+}
+
+static int expect_count(int want, const char *story)
+{
+ test_ct++;
+ if (want != trace_ct) {
+ pr_err("expect_count: want %d, got %d: %s\n", want, trace_ct, story);
+ errors++;
+ trace_ct = 0;
+ return 1;
+ }
+ pr_info("pass %d, hits %d, on \"%s\"\n", test_ct, want, story);
+ trace_ct = 0;
+ return 0;
+}
+
+/* call pr_debug (4 * reps) + 2 times, for tracer side-effects */
+static void do_debugging(int reps)
+{
+ int i;
+
+ pr_debug("Entry:\n");
+ pr_info(" do_debugging %d time(s)\n", reps);
+ for (i = 0; i < reps; i++) {
+ pr_debug("hi: %d\n", i);
+ pr_debug("mid: %d\n", i);
+ pr_debug("low: %d\n", i);
+ pr_debug("low:lower: %d subcategory test\n", i);
+ }
+ pr_debug("Exit:\n");
+}
+
+static void expect_matches(int want, int got, const char *story)
+{
+ // todo: got <0 are errors, bubbled up
+ if (got != want)
+ pr_warn(" match_count wrong: want %d got %d on \"%s\"\n", want, got, story);
+ else
+ pr_info(" ok: %d matches by \"%s\"\n", want, story);
+
+ // ? count errs ? separately ?
+}
+
+static int report(char *who)
+{
+ if (errors)
+ pr_err("%s failed %d of %d tests\n", who, errors, test_ct);
+ else
+ pr_info("%s passed %d tests\n", who, test_ct);
+ return errors;
+}
+
+struct exec_test {
+ int matches;
+ int loops;
+ int hits;
+ const char *mod;
+ const char *qry;
+};
+
+static void do_exec_test(struct exec_test *tst)
+{
+ int match_count;
+
+ match_count = dynamic_debug_exec_queries(tst->qry, tst->mod);
+ expect_matches(tst->matches, match_count, tst->qry);
+ do_debugging(tst->loops);
+ expect_count(tst->hits, tst->qry);
+}
+
+static const char my_mod[] = "test_dynamic_debug";
+
+/* these tests rely on register stuff having been done ?? */
+struct exec_test exec_tests[] = {
+
+ /* standard use is my_mod, for `modprobe $module dyndbg=+p` */
+
+ /* no modification probe */
+ { 6, 2, 0, my_mod, "func do_debugging +_" },
+
+ /* use original single string query style */
+ { 6, 3, 0, NULL, "module test_dynamic_debug func do_debugging -T" },
+
+ /* this is mildly preferred */
+ { 6, 3, 0, my_mod, "func do_debugging -T" },
+
+ /* enable all DUT */
+ { 6, 4, 18, my_mod, "func do_debugging +T" },
+
+ /* disable 1 call */
+ { 1, 4, 14, my_mod, "format '^hi:' -T" },
+
+ /* disable 1 call */
+ { 1, 4, 10, my_mod, "format '^mid:' -T" },
+
+ /* repeat same disable */
+ { 1, 4, 10, my_mod, "format '^mid:' -T" },
+
+ /* repeat same disable, diff run ct */
+ { 1, 5, 12, my_mod, "format '^mid:' -T" },
+
+ /* include subclass */
+ { 2, 4, 2, my_mod, "format '^low:' -T" },
+
+ /* re-disable, exclude subclass */
+ { 1, 4, 2, my_mod, "format '^low: ' -T" },
+
+ /* enable, exclude subclass */
+ { 1, 4, 6, my_mod, "format '^low: ' +T" },
+
+ /* enable the subclass */
+ { 1, 4, 10, my_mod, "format '^low:lower:' +T" },
+
+ /* enable the subclass */
+ { 1, 6, 14, my_mod, "format '^low:lower:' +T" },
+};
+
+struct register_test {
+ int matches;
+ int loops;
+ int hits;
+ const char *mod;
+ const char *qry;
+};
+
+static void do_register_test(struct register_test *tst)
+{
+ int match_count;
+
+ match_count = dynamic_debug_register_tracer(tst->qry, tst->mod, my_tracer);
+ expect_matches(tst->matches, match_count, tst->qry);
+ do_debugging(tst->loops);
+ expect_count(tst->hits, tst->qry);
+}
+
+struct register_test register_tests[] = {
+
+ { 6, 3, 14, my_mod, "func do_debugging +T" },
+
+ { 10, 3, 0, my_mod, "+_" }, //, my_tracer },
+ { 11, 3, 0, my_mod, "+T" }, //, my_tracer },
+};
+
+static int __init test_dynamic_debug_init(void)
+{
+ int match_count; /* rc from ddebug_exec_queries. meh. */
+ int i;
+
+ pick_tracer();
+
+ pr_debug("Entry:\n");
+ do_debugging(3);
+ expect_count(0, "nothing unless dyndbg=+T at modprobe");
+
+ for (i = 0; i < ARRAY_SIZE(register_tests); i++)
+ do_register_test(&register_tests[i]);
+
+ do_debugging(2);
+ expect_count(10, "do_debugging 2 times after +T");
+
+ for (i = 0; i < ARRAY_SIZE(exec_tests); i++)
+ do_exec_test(&exec_tests[i]);
+
+ match_count = dynamic_debug_unregister_tracer(
+ "func do_debugging -T", "test_dynamic_debug", my_tracer);
+
+ expect_matches(6, match_count,
+ "unregister do_debugging()s tracers");
+ do_debugging(4);
+ expect_count(0, "everything is off");
+
+ match_count = dynamic_debug_unregister_tracer(
+ "func do_debugging -T", "test_dynamic_debug", my_tracer);
+
+ expect_matches(6, match_count,
+ "re-unregister, same count, not a change count");
+ report("init");
+ pr_debug("Exit:\n");
+ return 0;
+}
+
+static void __exit test_dynamic_debug_exit(void)
+{
+ report("exit");
+ pr_debug("Exit:");
+}
+
+module_init(test_dynamic_debug_init);
+module_exit(test_dynamic_debug_exit);
+
+MODULE_AUTHOR("Jim Cromie <[email protected]>");
+MODULE_LICENSE("GPL");
--
2.31.1

2021-08-13 15:29:20

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 1/9] drm/print: fixup spelling in a comment

s/prink/printk/ - no functional changes

Signed-off-by: Jim Cromie <[email protected]>
---
include/drm/drm_print.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 9b66be54dd16..15a089a87c22 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -327,7 +327,7 @@ static inline bool drm_debug_enabled(enum drm_debug_category category)
/*
* struct device based logging
*
- * Prefer drm_device based logging over device or prink based logging.
+ * Prefer drm_device based logging over device or printk based logging.
*/

__printf(3, 4)
--
2.31.1

2021-08-13 15:29:21

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 5/9] i915/gvt: use DEFINE_DYNAMIC_DEBUG_CATEGORIES to create "gvt:core:" etc categories

The gvt component of this driver has ~120 pr_debugs, in 9 categories
quite similar to those in DRM. Following the interface model of
drm.debug, add a parameter to map bits to these categorizations.

DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
"dyndbg bitmap desc",
{ "gvt:cmd: ", "command processing" },
{ "gvt:core: ", "core help" },
{ "gvt:dpy: ", "display help" },
{ "gvt:el: ", "help" },
{ "gvt:irq: ", "help" },
{ "gvt:mm: ", "help" },
{ "gvt:mmio: ", "help" },
{ "gvt:render: ", "help" },
{ "gvt:sched: " "help" });

The actual patch has a few details different, cmd_help() macro emits
the initialization construct.

if CONFIG_DRM_USE_DYNAMIC_DEBUG, then -DDYNAMIC_DEBUG_MODULE is added
cflags, by gvt/Makefile.

---
v4+:
. static decl of vector of bit->class descriptors - Emil.V
. relocate gvt-makefile chunk from elsewhere

Signed-off-by: Jim Cromie <[email protected]>
---
drivers/gpu/drm/i915/gvt/Makefile | 4 ++++
drivers/gpu/drm/i915/i915_params.c | 35 ++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile
index ea8324abc784..846ba73b8de6 100644
--- a/drivers/gpu/drm/i915/gvt/Makefile
+++ b/drivers/gpu/drm/i915/gvt/Makefile
@@ -7,3 +7,7 @@ GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \

ccflags-y += -I $(srctree)/$(src) -I $(srctree)/$(src)/$(GVT_DIR)/
i915-y += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))
+
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+ccflags-y += -DDYNAMIC_DEBUG_MODULE
+#endif
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index e07f4cfea63a..683e942a074e 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -265,3 +265,38 @@ void i915_params_free(struct i915_params *params)
I915_PARAMS_FOR_EACH(FREE);
#undef FREE
}
+
+#ifdef DRM_USE_DYNAMIC_DEBUG
+/* todo: needs DYNAMIC_DEBUG_MODULE in some cases */
+
+unsigned long __gvt_debug;
+EXPORT_SYMBOL(__gvt_debug);
+
+#define _help(key) "\t \"" key "\"\t: help for " key "\n"
+
+#define I915_GVT_CATEGORIES(name) \
+ " Enable debug output via /sys/module/i915/parameters/" #name \
+ ", where each bit enables a debug category.\n" \
+ _help("gvt:cmd:") \
+ _help("gvt:core:") \
+ _help("gvt:dpy:") \
+ _help("gvt:el:") \
+ _help("gvt:irq:") \
+ _help("gvt:mm:") \
+ _help("gvt:mmio:") \
+ _help("gvt:render:") \
+ _help("gvt:sched:")
+
+DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
+ I915_GVT_CATEGORIES(debug_gvt),
+ _DD_cat_("gvt:cmd:"),
+ _DD_cat_("gvt:core:"),
+ _DD_cat_("gvt:dpy:"),
+ _DD_cat_("gvt:el:"),
+ _DD_cat_("gvt:irq:"),
+ _DD_cat_("gvt:mm:"),
+ _DD_cat_("gvt:mmio:"),
+ _DD_cat_("gvt:render:"),
+ _DD_cat_("gvt:sched:"));
+
+#endif
--
2.31.1

2021-08-13 15:30:38

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 6/9] amdgpu: use DEFINE_DYNAMIC_DEBUG_CATEGORIES to control categorized pr_debugs

logger_types.h defines many DC_LOG_*() categorized debug wrappers.
Most of these use DRM debug API, so are controllable using drm.debug,
but others use bare pr_debug("$prefix: .."), each with a different
class-prefix matching "^\[\w+\]:"

Use DEFINE_DYNAMIC_DEBUG_CATEGORIES to create a /sys debug_dc
parameter, modinfos, and to specify a map from bits -> categorized
pr_debugs to be controlled.

Signed-off-by: Jim Cromie <[email protected]>
---
.../gpu/drm/amd/display/dc/core/dc_debug.c | 44 ++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_debug.c b/drivers/gpu/drm/amd/display/dc/core/dc_debug.c
index 21be2a684393..69e68d721512 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_debug.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_debug.c
@@ -36,8 +36,50 @@

#include "resource.h"

-#define DC_LOGGER_INIT(logger)
+#ifdef DRM_USE_DYNAMIC_DEBUG
+/* define a drm.debug style dyndbg pr-debug control point */
+#include <linux/dynamic_debug.h>
+
+unsigned long __debug_dc;
+EXPORT_SYMBOL(__debug_dc);
+
+#define _help_(key) "\t " key "\t- help for " key "\n"
+
+/* Id like to do these inside DEFINE_DYNAMIC_DEBUG_CATEGORIES, if possible */
+#define DC_DYNDBG_BITMAP_DESC(name) \
+ "Control pr_debugs via /sys/module/amdgpu/parameters/" #name \
+ ", where each bit controls a debug category.\n" \
+ _help_("[SURFACE]:") \
+ _help_("[CURSOR]:") \
+ _help_("[PFLIP]:") \
+ _help_("[VBLANK]:") \
+ _help_("[HW_LINK_TRAINING]:") \
+ _help_("[HW_AUDIO]:") \
+ _help_("[SCALER]:") \
+ _help_("[BIOS]:") \
+ _help_("[BANDWIDTH_CALCS]:") \
+ _help_("[DML]:") \
+ _help_("[IF_TRACE]:") \
+ _help_("[GAMMA]:") \
+ _help_("[SMU_MSG]:")
+
+DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_dc, __debug_dc,
+ DC_DYNDBG_BITMAP_DESC(debug_dc),
+ _DD_cat_("[CURSOR]:"),
+ _DD_cat_("[PFLIP]:"),
+ _DD_cat_("[VBLANK]:"),
+ _DD_cat_("[HW_LINK_TRAINING]:"),
+ _DD_cat_("[HW_AUDIO]:"),
+ _DD_cat_("[SCALER]:"),
+ _DD_cat_("[BIOS]:"),
+ _DD_cat_("[BANDWIDTH_CALCS]:"),
+ _DD_cat_("[DML]:"),
+ _DD_cat_("[IF_TRACE]:"),
+ _DD_cat_("[GAMMA]:"),
+ _DD_cat_("[SMU_MSG]:"));
+#endif

+#define DC_LOGGER_INIT(logger)

#define SURFACE_TRACE(...) do {\
if (dc->debug.surface_trace) \
--
2.31.1

2021-08-13 15:46:02

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v5 2/9] moduleparam: add data member to struct kernel_param

On Fri, Aug 13, 2021 at 09:17:10AM -0600, Jim Cromie wrote:
> Add a const void* data member to the struct, to allow attaching
> private data that will be used soon by a setter method (via kp->data)
> to perform more elaborate actions.
>
> To attach the data at compile time, add new macros:
>
> module_param_cbd() derives from module_param_cb(), adding data param,
> and latter is redefined to use former.
>
> It calls __module_param_call_wdata(), which accepts a new data param
> and inits .data with it. Re-define __module_param_call() to use it.
>
> Use of this new data member will be rare, it might be worth redoing
> this as a separate/sub-type to de-bloat the base case.

...

> +#define module_param_cbd(name, ops, arg, perm, data) \
> + __module_param_call_wdata(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0, data)

Cryptic name. Moreover, inconsistent with the rest.
What about module_param_cb_data() ?

> #define module_param_cb_unsafe(name, ops, arg, perm) \
> __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
> KERNEL_PARAM_FL_UNSAFE)

(above left for the above comment)

...

> +#define __module_param_call_wdata(prefix, name, ops, arg, perm, level, flags, data) \

Similar __module_param_call_with_data()

--
With Best Regards,
Andy Shevchenko


2021-08-13 15:54:13

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v5 3/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks

On Fri, Aug 13, 2021 at 09:17:11AM -0600, Jim Cromie wrote:
> DEFINE_DYNAMIC_DEBUG_CATEGORIES(name, var, bitmap_desc, @bit_descs)
> allows users to define a drm.debug style (bitmap) sysfs interface, and
> to specify the desired mapping from bits[0-N] to the format-prefix'd
> pr_debug()s to be controlled.
>
> DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
> "i915/gvt bitmap desc",
> /**
> * search-prefixes, passed to dd-exec_queries
> * defines bits 0-N in order.
> * leading ^ is tacitly inserted (by callback currently)
> * trailing space used here excludes subcats.
> * helper macro needs more work
> * macro to autogen ++$i, 0x%x$i ?
> */
> _DD_cat_("gvt:cmd: "),
> _DD_cat_("gvt:core: "),
> _DD_cat_("gvt:dpy: "),
> _DD_cat_("gvt:el: "),
> _DD_cat_("gvt:irq: "),
> _DD_cat_("gvt:mm: "),
> _DD_cat_("gvt:mmio: "),
> _DD_cat_("gvt:render: "),
> _DD_cat_("gvt:sched: "));
>
> dynamic_debug.c: add 3 new elements:
>
> - int param_set_dyndbg()
> - int param_get_dyndbg()
> - struct kernel_param_ops param_ops_dyndbg
>
> Following the model of kernel/params.c STANDARD_PARAM_DEFS, All 3 are
> non-static and exported.
>
> dynamic_debug.h:
>
> Add DEFINE_DYNAMIC_DEBUG_CATEGORIES() described above, and a do-nothing stub.
>
> Note that it also calls MODULE_PARM_DESC for the user, but expects the
> user to catenate all the bit-descriptions together (as is done in
> drm.debug), and in the following uses in amdgpu, i915.
>
> This in the hope that someone can offer an auto-incrementing
> label-generating macro, producing "\tbit-4 0x10\t" etc, and can show
> how to apply it to __VA_ARGS__.
>
> Also extern the struct kernel_param param_ops_dyndbg symbol, as is
> done in moduleparams.h for all the STANDARD params.
>
> USAGE NOTES:
>
> Using dyndbg to query on "format ^$prefix" requires that the prefix be
> present in the compiled-in format string; where run-time prefixing is
> used, that format would be "%s...", which is not usefully selectable.
>
> Adding structural query terms (func,file,lineno) could help (module is
> already done), but DEFINE_DYNAMIC_DEBUG_CATEGORIES can't do that now,
> adding it needs a better reason imo.
>
> Dyndbg is completely agnostic wrt the categorization scheme used, to
> play well with any prefix convention already in use. Ad-hoc
> categories and sub-categories are implicitly allowed, author
> discipline and review is expected.
>
> Here are some examples:
>
> "1","2","3" 2 doesnt imply 1.
> otherwize, sorta like printk levels
> "1:","2:","3:" are better, avoiding [1-9]\d+ ambiguity
> "hi:","mid:","low:" are reasonable, and imply independence
> "todo:","rfc:" might be handy
> "A:".."Z:" uhm, yeah
>
> Hierarchical classes/categories are natural:
>
> "drm:<CAT>:" is used in later commit
> "drm:<CAT>:<SUB>:" is a natural extension.
> "drm:atomic:fail:" has been proposed, sounds directly useful
>
> Some properties of a hierarchical category deserve explication:
>
> Trailing spaces matter !
>
> With 1..3-space ("drm: ", "drm:atomic: ", "drm:atomic:fail: "), the
> ":" doesnt terminate the search-space, the trailing space does.
> So a "drm:" search specification will match all DRM categories &
> subcategories, and will not be useful in an interface where all
> categories are controlled together. That said, "drm:atomic:" &
> "drm:atomic: " are different, and both are useful in cases.
>
> Ad-Hoc sub-categories:
>
> These have a caveat wrt wrapper macros adding prefixes like
> "drm:atomic: "; the trailing space in the prefix means that
> drm_dbg("fail: ...") renders as "drm:atomic: fail: ", which obviously
> isn't ideal wrt clear and simple bitmaps.
>
> A possible solution is to have a FOO_() version of every FOO() macro
> which (anti-mnemonically) elides the trailing space, which is normally
> inserted by a modified FOO(). Doing this would enforce a policy
> decision that "debug categories will be space terminated", with an
> pressure-relief valve.
>
> Summarizing:
>
> - "drm:kms: " & "drm:kms:" are different
> - "drm:kms" also different - includes drm:kms2:
> - "drm:kms:\t" also different
> - "drm:kms:*" doesnt work, no wildcard on format atm.
>
> Order matters in DEFINE_DYNAMIC_DEBUG_CATEGORIES(... @bit_descs)
>
> @bit_descs (array) position determines the bit mapping to the prefix,
> so to keep a stable map, new categories or 3rd level categories must
> be added to the end.
>
> Since bits are/will-stay applied 0-N, the later bits can countermand
> the earlier ones, but its tricky - consider;
>
> DD_CATs(... "drm:atomic:", ""drm:atomic:fail:" ) // misleading
>
> The 1st search-term is misleading, because it includes (modifies)
> subcategories, but then 2nd overrides it. So don't do that.
>
> There is still plenty of bikeshedding to do.

> ---
> v4+:
>
> . rename to DEFINE_DYNAMIC_DEBUG_CATEGORIES from DEFINE_DYNDBG_BITMAP
> . in query, replace hardcoded "i915" w kp->mod->name
> . static inline the stubs
> . const *str in structs, const array. -Emil
> . dyndbg: add do-nothing DEFINE_DYNAMIC_DEBUG_CATEGORIES if !DD_CORE
> . call MOD_PARM_DESC(name, "$desc") for users
> . simplify callback, remove bit-change detection
> . config errs reported by <[email protected]>
>
> ddh-helpers

> Signed-off-by: Jim Cromie <[email protected]>

So, it is signed or not? I didn't get (perhaps due to misplaced changlog?).

...

> } __attribute__((aligned(8)));
>
>

Do we need two blank lines here?

> +struct kernel_param;

...

> +int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
> +{
> + unsigned long inbits;
> + int rc, i, chgct = 0, totct = 0;
> + char query[OUR_QUERY_SIZE];
> + struct dyndbg_bitdesc *bitmap = (struct dyndbg_bitdesc *) kp->data;

So you need space after ')' ?

> + rc = kstrtoul(instr, 0, &inbits);
> + if (rc) {
> + pr_err("set_dyndbg: failed\n");

> + return -EINVAL;

Why not to return rc?

> + }
> + vpr_info("set_dyndbg: input 0x%lx\n", inbits);
> +
> + for (i = 0; !!bitmap[i].prefix; i++) {

Hmm... Why not simply

for (bitmap = ...; bitmap->prefix; bitmap++) {

?

> +

Redundant blank line.

> + sprintf(query, "format '^%s' %cp", bitmap[i].prefix,
> + test_bit(i, &inbits) ? '+' : '-');

snprintf() ?

> +
> + chgct = dynamic_debug_exec_queries(query, kp->mod->name);
> +
> + v2pr_info("bit-%d: %d changes by '%s'\n", i, chgct, query);
> + totct += chgct;
> + }
> + vpr_info("total changes: %d\n", totct);
> + return 0;
> +}

...

> + return scnprintf(buffer, PAGE_SIZE, "%u\n",
> + *((unsigned int *)kp->arg));

One line.

--
With Best Regards,
Andy Shevchenko


2021-08-13 17:05:20

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 4/9] i915/gvt: remove spaces in pr_debug "gvt: core:" etc prefixes

Taking embedded spaces out of existing prefixes makes them better
class-prefixes; simplifying the nested quoting needed otherwise:

$> echo "format '^gvt: core:' +p" >control

Dropping the internal spaces means any trailing space in a query will
more clearly terminate the prefix being searched for.

Consider a generic drm-debug example:

# turn off ATOMIC reports
echo format "^drm:atomic: " -p > control

# turn off all ATOMIC:* reports, including any sub-categories
echo format "^drm:atomic:" -p > control

# turn on ATOMIC:FAIL: reports
echo format "^drm:atomic:fail: " +p > control

Removing embedded spaces in the class-prefixes simplifies the
corresponding match-prefix. This means that "quoted" match-prefixes
are only needed when the trailing space is desired, in order to
exclude explicitly sub-categorized pr-debugs; in this example,
"drm:atomic:fail:".

RFC: maybe the prefix catenation should paste in the " " class-prefix
terminator explicitly. A pr_debug_() flavor could exclude the " ",
allowing ad-hoc sub-categorization by appending for example, "fail:"
to "drm:atomic:".

Signed-off-by: Jim Cromie <[email protected]>
---
drivers/gpu/drm/i915/gvt/debug.h | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/debug.h b/drivers/gpu/drm/i915/gvt/debug.h
index c6027125c1ec..b4021f41c546 100644
--- a/drivers/gpu/drm/i915/gvt/debug.h
+++ b/drivers/gpu/drm/i915/gvt/debug.h
@@ -36,30 +36,30 @@ do { \
} while (0)

#define gvt_dbg_core(fmt, args...) \
- pr_debug("gvt: core: "fmt, ##args)
+ pr_debug("gvt:core: "fmt, ##args)

#define gvt_dbg_irq(fmt, args...) \
- pr_debug("gvt: irq: "fmt, ##args)
+ pr_debug("gvt:irq: "fmt, ##args)

#define gvt_dbg_mm(fmt, args...) \
- pr_debug("gvt: mm: "fmt, ##args)
+ pr_debug("gvt:mm: "fmt, ##args)

#define gvt_dbg_mmio(fmt, args...) \
- pr_debug("gvt: mmio: "fmt, ##args)
+ pr_debug("gvt:mmio: "fmt, ##args)

#define gvt_dbg_dpy(fmt, args...) \
- pr_debug("gvt: dpy: "fmt, ##args)
+ pr_debug("gvt:dpy: "fmt, ##args)

#define gvt_dbg_el(fmt, args...) \
- pr_debug("gvt: el: "fmt, ##args)
+ pr_debug("gvt:el: "fmt, ##args)

#define gvt_dbg_sched(fmt, args...) \
- pr_debug("gvt: sched: "fmt, ##args)
+ pr_debug("gvt:sched: "fmt, ##args)

#define gvt_dbg_render(fmt, args...) \
- pr_debug("gvt: render: "fmt, ##args)
+ pr_debug("gvt:render: "fmt, ##args)

#define gvt_dbg_cmd(fmt, args...) \
- pr_debug("gvt: cmd: "fmt, ##args)
+ pr_debug("gvt:cmd: "fmt, ##args)

#endif
--
2.31.1

2021-08-13 17:05:22

by Jim Cromie

[permalink] [raw]
Subject: [PATCH v5 7/9] drm_print: add choice to use dynamic debug in drm-debug

drm's debug system writes 10 distinct categories of messages to syslog
using a small API[1]: drm_dbg*(10 names), DRM_DEBUG*(8 names),
DRM_DEV_DEBUG*(3 names). There are thousands of these callsites, each
categorized by their authors.

These callsites can be enabled at runtime by their category, each
controlled by a bit in drm.debug (/sys/modules/drm/parameter/debug).
In the current "basic" implementation, drm_debug_enabled() tests these
bits in __drm_debug each time an API[1] call is executed; while cheap
individually, the costs accumulate.

This patch uses dynamic-debug with jump-label to patch enabled calls
onto their respective NOOP slots, avoiding all runtime bit-checks of
__drm_debug.

Dynamic debug has no concept of category, but we can emulate one by
replacing enum categories with a set of prefix-strings; "drm:core:",
"drm:kms:" "drm:driver:" etc, and prepend them (at compile time) to
the given formats.

Then we can use:
`echo module drm format "^drm:core: " +p > control`

to enable the whole category with one query.

This conversion yields ~2100 new callsites on my i7/i915 laptop:

dyndbg: 195 debug prints in module drm_kms_helper
dyndbg: 298 debug prints in module drm
dyndbg: 1630 debug prints in module i915

CONFIG_DRM_USE_DYNAMIC_DEBUG enables this, and is available if
CONFIG_DYNAMIC_DEBUG or CONFIG_DYNAMIC_DEBUG_CORE is chosen, and if
CONFIG_JUMP_LABEL is enabled; this because its required to get the
promised optimizations.

The "basic" -> "dyndbg" switchover is layered into the macro scheme

A. use DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug, __drm_debug,
"DRM debug category-per-bit control",
{ "drm:core:", "enable CORE debug messages" },
{ "drm:kms:", "enable KMS debug messages" }, ...);

B. A "classy" version of DRM_UT_<CATs> map, named DRM_DBG_CAT_<CATs>

DRM_DBG_CLASS_<CATs> was proposed, I had agreed, but reconsidered;
CATEGORY is already DRM's term-of-art, and adding a near-synonym
'CLASS' only adds ambiguity.

"basic": DRM_DBG_CAT_<CATs> <=== DRM_UT_<CATs>. Identity map.
"dyndbg":
#define DRM_DBG_CAT_KMS "drm:kms: "
#define DRM_DBG_CAT_PRIME "drm:prime: "
#define DRM_DBG_CAT_ATOMIC "drm:atomic: "

DRM_UT_* are preserved, since theyre used elsewhere.
We can probably reduce its use further, but thats a separate thing.

C. drm_dev_dbg() & drm_debug() are interposed with macros

basic: forward to renamed fn, with args preserved
enabled: redirect to pr_debug, dev_dbg, with CATEGORY # format

this is where drm_debug_enabled() is avoided.
prefix is prepended at compile-time, no category at runtime.

D. API[1] uses DRM_DBG_CAT_<CAT>s
these already use (C), now they use (B) too,
to get the correct token type for "basic" and "dyndbg" configs.

NOTES:

Code Review is expected to catch lack of correspondence between
bit=>prefix definitions (the selector) and the prefixes used in the
API[1] layer above pr_debug()

I've coded the search-prefixes/categories with a trailing space, which
excludes any sub-categories added later. This convention protects any
"drm:atomic:fail:" callsites from getting stomped on by `echo 0 > debug`.
Other categories could differ, but we need some default.

Dyndbg requires that the prefix be in the compiled-in format string;
run-time prefixing evades callsite selection by category.

pr_debug("%s: ...", __func__, ...) // not ideal

With "lineno X" in a query, its possible to enable single callsites,
but it is tedious, and useless in a category context.

Unfortunately __func__ is not a macro, and cannot be catenated at
preprocess/compile time.

pr_debug("Entry: ...") // +fml gives useful log-info
pr_debug("Exit: ...") // hard to catch them all

But "func foo" added to query-command would work, should it be useful
enough to justify extending the declarative interface.

---
v4+:

. use DEFINE_DYNAMIC_DEBUG_CATEGORIES in drm_print.c
. s/DRM_DBG_CLASS_/DRM_DBG_CAT_/ - dont need another term
. default=y in KBuild entry - per @DanVet
. move some commit-log prose to dyndbg commit
. add-prototyes to (param_get/set)_dyndbg
. more wrinkles found by <[email protected]>
. relocate ratelimit chunk from elsewhere
. add kernel doc

Signed-off-by: Jim Cromie <[email protected]>
---
drivers/gpu/drm/Kconfig | 13 ++++
drivers/gpu/drm/drm_print.c | 49 +++++++++----
include/drm/drm_print.h | 141 ++++++++++++++++++++++++++++--------
3 files changed, 159 insertions(+), 44 deletions(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 7ff89690a976..97e38d86fd27 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -57,6 +57,19 @@ config DRM_DEBUG_MM

If in doubt, say "N".

+config DRM_USE_DYNAMIC_DEBUG
+ bool "use dynamic debug to implement drm.debug"
+ default y
+ depends on DRM
+ depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+ depends on JUMP_LABEL
+ help
+ The "basic" drm.debug facility does a lot of unlikely
+ bit-field tests at runtime; while cheap individually, the
+ cost accumulates. DYNAMIC_DEBUG patches pr_debug()s in/out
+ of the running kernel, so avoids those bit-test overheads,
+ and is therefore recommended.
+
config DRM_DEBUG_SELFTEST
tristate "kselftests for DRM"
depends on DRM
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index 111b932cf2a9..72b940a30779 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -28,6 +28,7 @@
#include <stdarg.h>

#include <linux/io.h>
+#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
@@ -43,16 +44,36 @@
unsigned int __drm_debug;
EXPORT_SYMBOL(__drm_debug);

-MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
-"\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
-"\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
-"\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
-"\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
-"\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
-"\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n"
-"\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n"
-"\t\tBit 8 (0x100) will enable DP messages (displayport code)");
+#define DRM_DEBUG_DESC \
+"Enable debug output, where each bit enables a debug category.\n" \
+"\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n" \
+"\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n" \
+"\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n" \
+"\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n" \
+"\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n" \
+"\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n" \
+"\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n" \
+"\t\tBit 8 (0x100) will enable DP messages (displayport code)."
+
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+#include <linux/dynamic_debug.h>
+DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug, __drm_debug,
+ DRM_DEBUG_DESC,
+ _DD_cat_(DRM_DBG_CAT_CORE),
+ _DD_cat_(DRM_DBG_CAT_DRIVER),
+ _DD_cat_(DRM_DBG_CAT_KMS),
+ _DD_cat_(DRM_DBG_CAT_PRIME),
+ _DD_cat_(DRM_DBG_CAT_ATOMIC),
+ _DD_cat_(DRM_DBG_CAT_VBL),
+ _DD_cat_(DRM_DBG_CAT_STATE),
+ _DD_cat_(DRM_DBG_CAT_LEASE),
+ _DD_cat_(DRM_DBG_CAT_DP),
+ _DD_cat_(DRM_DBG_CAT_DRMRES));
+
+#else
+MODULE_PARM_DESC(debug, DRM_DEBUG_DESC);
module_param_named(debug, __drm_debug, int, 0600);
+#endif

void __drm_puts_coredump(struct drm_printer *p, const char *str)
{
@@ -256,8 +277,8 @@ void drm_dev_printk(const struct device *dev, const char *level,
}
EXPORT_SYMBOL(drm_dev_printk);

-void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
- const char *format, ...)
+void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
+ const char *format, ...)
{
struct va_format vaf;
va_list args;
@@ -278,9 +299,9 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,

va_end(args);
}
-EXPORT_SYMBOL(drm_dev_dbg);
+EXPORT_SYMBOL(__drm_dev_dbg);

-void __drm_dbg(enum drm_debug_category category, const char *format, ...)
+void ___drm_dbg(enum drm_debug_category category, const char *format, ...)
{
struct va_format vaf;
va_list args;
@@ -297,7 +318,7 @@ void __drm_dbg(enum drm_debug_category category, const char *format, ...)

va_end(args);
}
-EXPORT_SYMBOL(__drm_dbg);
+EXPORT_SYMBOL(___drm_dbg);

void __drm_err(const char *format, ...)
{
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 15a089a87c22..aca56b456277 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -252,15 +252,15 @@ static inline struct drm_printer drm_err_printer(const char *prefix)
/**
* enum drm_debug_category - The DRM debug categories
*
- * Each of the DRM debug logging macros use a specific category, and the logging
- * is filtered by the drm.debug module parameter. This enum specifies the values
- * for the interface.
+ * The drm.debug logging API[1] has 10 enumerated categories of
+ * messages, issued by 3 families of macros: 10 drm_dbg_<CATs>, 8
+ * DRM_DEBUG_<CATs>, and 3 DRM_DEV_DEBUG_<CATs>.
*
* Each DRM_DEBUG_<CATEGORY> macro logs to DRM_UT_<CATEGORY> category, except
* DRM_DEBUG() logs to DRM_UT_CORE.
*
- * Enabling verbose debug messages is done through the drm.debug parameter, each
- * category being enabled by a bit:
+ * Enabling categories of debug messages is done through the drm.debug
+ * parameter, each category being enabled by a bit:
*
* - drm.debug=0x1 will enable CORE messages
* - drm.debug=0x2 will enable DRIVER messages
@@ -319,6 +319,85 @@ enum drm_debug_category {
DRM_UT_DRMRES = 0x200,
};

+/**
+ * DOC: DRM_USE_DYNAMIC_DEBUG - using dyndbg in drm.debug
+ *
+ * In the "basic" drm.debug implementation outlined above, each time a
+ * drm-debug API[1] call is executed, drm_debug_enabled(cat) tests
+ * drm.debug vs cat before printing.
+ *
+ * DYNAMIC_DEBUG (aka: dyndbg) patches pr_debug()s in^out of the
+ * running kernel, so it can avoid drm_debug_enabled() and skip lots
+ * of unlikely bit tests.
+ *
+ * dyndbg has no concept of category, but we can prepend a
+ * class-prefix string: "drm:core: ", "drm:kms: ", "drm:driver: " etc,
+ * to pr_debug's format (at compile time).
+ *
+ * Then control the category
+ * `echo module drm format "^drm:core: " +p > control`
+ * `dynamic_debug_exec_queries("format '^drm:core: ' +p", "drm");`
+ *
+ * To do this for "basic" | "dyndbg", adaptation adds some macro indirection:
+ *
+ * 0. use dyndbg support to define the bits => prefixes map, attach callback.
+ *
+ * DYNDBG_BITMAP_DESC(debug, __drm_debug,
+ * "drm.debug - overview",
+ * { "drm:core:", "enable CORE debug messages" },
+ * { "drm:kms:", "enable KMS debug messages" }, ...);
+ *
+ * 1. DRM_DBG_CAT_<CAT>
+ *
+ * This set of symbols replaces DRM_UT_<CAT> in the drm-debug API; it
+ * is either a copy of DRM_UT_<CAT>, or the class-prefix strings.
+ *
+ * 2. drm_dev_dbg & drm_debug are called by drm.debug API
+ *
+ * These are now macros, either forwarding to renamed functions, or
+ * prepending the class string to the format, and invoking pr_debug
+ * directly. Since the API is all macros, dyndbg remembers
+ * per-pr_debug: module,file,func,line,format and uses that to find
+ * and enable them.
+ */
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+
+#define __drm_dbg(cls, fmt, ...) \
+ ___drm_dbg(cls, fmt, ##__VA_ARGS__)
+#define drm_dev_dbg(dev, cls, fmt, ...) \
+ __drm_dev_dbg(dev, cls, fmt, ##__VA_ARGS__)
+
+#define DRM_DBG_CAT_CORE DRM_UT_CORE
+#define DRM_DBG_CAT_DRIVER DRM_UT_DRIVER
+#define DRM_DBG_CAT_KMS DRM_UT_KMS
+#define DRM_DBG_CAT_PRIME DRM_UT_PRIME
+#define DRM_DBG_CAT_ATOMIC DRM_UT_ATOMIC
+#define DRM_DBG_CAT_VBL DRM_UT_VBL
+#define DRM_DBG_CAT_STATE DRM_UT_STATE
+#define DRM_DBG_CAT_LEASE DRM_UT_LEASE
+#define DRM_DBG_CAT_DP DRM_UT_DP
+#define DRM_DBG_CAT_DRMRES DRM_UT_DRMRES
+
+#else /* !CONFIG_DRM_USE_DYNAMIC_DEBUG */
+
+#define __drm_dbg(cls, fmt, ...) \
+ pr_debug(cls # fmt, ##__VA_ARGS__)
+#define drm_dev_dbg(dev, cls, fmt, ...) \
+ dev_dbg(dev, cls # fmt, ##__VA_ARGS__)
+
+#define DRM_DBG_CAT_CORE "drm:core: "
+#define DRM_DBG_CAT_DRIVER "drm:drvr: "
+#define DRM_DBG_CAT_KMS "drm:kms: "
+#define DRM_DBG_CAT_PRIME "drm:prime: "
+#define DRM_DBG_CAT_ATOMIC "drm:atomic: "
+#define DRM_DBG_CAT_VBL "drm:vbl: "
+#define DRM_DBG_CAT_STATE "drm:state: "
+#define DRM_DBG_CAT_LEASE "drm:lease: "
+#define DRM_DBG_CAT_DP "drm:dp: "
+#define DRM_DBG_CAT_DRMRES "drm:res "
+
+#endif /* !CONFIG_DRM_USE_DYNAMIC_DEBUG */
+
static inline bool drm_debug_enabled(enum drm_debug_category category)
{
return unlikely(__drm_debug & category);
@@ -334,8 +413,8 @@ __printf(3, 4)
void drm_dev_printk(const struct device *dev, const char *level,
const char *format, ...);
__printf(3, 4)
-void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
- const char *format, ...);
+void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
+ const char *format, ...);

/**
* DRM_DEV_ERROR() - Error output.
@@ -383,7 +462,7 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
* @fmt: printf() like format string.
*/
#define DRM_DEV_DEBUG(dev, fmt, ...) \
- drm_dev_dbg(dev, DRM_UT_CORE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(dev, DRM_DBG_CAT_CORE, fmt, ##__VA_ARGS__)
/**
* DRM_DEV_DEBUG_DRIVER() - Debug output for vendor specific part of the driver
*
@@ -391,7 +470,7 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
* @fmt: printf() like format string.
*/
#define DRM_DEV_DEBUG_DRIVER(dev, fmt, ...) \
- drm_dev_dbg(dev, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(dev, DRM_DBG_CAT_DRIVER, fmt, ##__VA_ARGS__)
/**
* DRM_DEV_DEBUG_KMS() - Debug output for modesetting code
*
@@ -399,7 +478,7 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
* @fmt: printf() like format string.
*/
#define DRM_DEV_DEBUG_KMS(dev, fmt, ...) \
- drm_dev_dbg(dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(dev, DRM_DBG_CAT_KMS, fmt, ##__VA_ARGS__)

/*
* struct drm_device based logging
@@ -443,25 +522,25 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,


#define drm_dbg_core(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_CORE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_CORE, fmt, ##__VA_ARGS__)
#define drm_dbg(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_DRIVER, fmt, ##__VA_ARGS__)
#define drm_dbg_kms(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_KMS, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_KMS, fmt, ##__VA_ARGS__)
#define drm_dbg_prime(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_PRIME, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_PRIME, fmt, ##__VA_ARGS__)
#define drm_dbg_atomic(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_ATOMIC, fmt, ##__VA_ARGS__)
#define drm_dbg_vbl(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_VBL, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_VBL, fmt, ##__VA_ARGS__)
#define drm_dbg_state(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_STATE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_STATE, fmt, ##__VA_ARGS__)
#define drm_dbg_lease(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_LEASE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_LEASE, fmt, ##__VA_ARGS__)
#define drm_dbg_dp(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DP, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_DP, fmt, ##__VA_ARGS__)
#define drm_dbg_drmres(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRMRES, fmt, ##__VA_ARGS__)
+ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_DRMRES, fmt, ##__VA_ARGS__)


/*
@@ -471,7 +550,7 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
*/

__printf(2, 3)
-void __drm_dbg(enum drm_debug_category category, const char *format, ...);
+void ___drm_dbg(enum drm_debug_category category, const char *format, ...);
__printf(1, 2)
void __drm_err(const char *format, ...);

@@ -500,29 +579,30 @@ void __drm_err(const char *format, ...);
#define DRM_ERROR_RATELIMITED(fmt, ...) \
DRM_DEV_ERROR_RATELIMITED(NULL, fmt, ##__VA_ARGS__)

+
#define DRM_DEBUG(fmt, ...) \
- __drm_dbg(DRM_UT_CORE, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_CORE, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_DRIVER(fmt, ...) \
- __drm_dbg(DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_DRIVER, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_KMS(fmt, ...) \
- __drm_dbg(DRM_UT_KMS, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_KMS, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_PRIME(fmt, ...) \
- __drm_dbg(DRM_UT_PRIME, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_PRIME, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_ATOMIC(fmt, ...) \
- __drm_dbg(DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_ATOMIC, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_VBL(fmt, ...) \
- __drm_dbg(DRM_UT_VBL, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_VBL, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_LEASE(fmt, ...) \
- __drm_dbg(DRM_UT_LEASE, fmt, ##__VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_LEASE, fmt, ##__VA_ARGS__)

#define DRM_DEBUG_DP(fmt, ...) \
- __drm_dbg(DRM_UT_DP, fmt, ## __VA_ARGS__)
+ __drm_dbg(DRM_DBG_CAT_DP, fmt, ## __VA_ARGS__)

#define __DRM_DEFINE_DBG_RATELIMITED(category, drm, fmt, ...) \
({ \
@@ -530,7 +610,8 @@ void __drm_err(const char *format, ...);
const struct drm_device *drm_ = (drm); \
\
if (drm_debug_enabled(DRM_UT_ ## category) && __ratelimit(&rs_)) \
- drm_dev_printk(drm_ ? drm_->dev : NULL, KERN_DEBUG, fmt, ## __VA_ARGS__); \
+ drm_dev_dbg((drm_) ? (drm_)->dev : NULL, \
+ DRM_DBG_CAT_ ## category, fmt, ##__VA_ARGS__); \
})

#define drm_dbg_kms_ratelimited(drm, fmt, ...) \
--
2.31.1

2021-08-13 17:06:10

by Matthew Wilcox

[permalink] [raw]
Subject: Re: [PATCH v5 3/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks

On Fri, Aug 13, 2021 at 06:51:05PM +0300, Andy Shevchenko wrote:
> On Fri, Aug 13, 2021 at 09:17:11AM -0600, Jim Cromie wrote:
> > +int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
> > +{
> > + unsigned long inbits;
> > + int rc, i, chgct = 0, totct = 0;
> > + char query[OUR_QUERY_SIZE];
> > + struct dyndbg_bitdesc *bitmap = (struct dyndbg_bitdesc *) kp->data;
>
> So you need space after ')' ?

More importantly, if ->data is of type 'void *', it is bad style to
cast the pointer at all. I can't tell what type 'data' has; if it
is added to kernel_param as part of this series, I wasn't cc'd on
the patch that did that.

2021-08-13 17:18:34

by Jim Cromie

[permalink] [raw]
Subject: Re: [PATCH v5 2/9] moduleparam: add data member to struct kernel_param

On Fri, Aug 13, 2021 at 9:44 AM Andy Shevchenko
<[email protected]> wrote:
>
> On Fri, Aug 13, 2021 at 09:17:10AM -0600, Jim Cromie wrote:
> > Add a const void* data member to the struct, to allow attaching
> > private data that will be used soon by a setter method (via kp->data)
> > to perform more elaborate actions.
> >
> > To attach the data at compile time, add new macros:
> >
> > module_param_cbd() derives from module_param_cb(), adding data param,
> > and latter is redefined to use former.
> >
> > It calls __module_param_call_wdata(), which accepts a new data param
> > and inits .data with it. Re-define __module_param_call() to use it.
> >
> > Use of this new data member will be rare, it might be worth redoing
> > this as a separate/sub-type to de-bloat the base case.
>
> ...
>
> > +#define module_param_cbd(name, ops, arg, perm, data) \
> > + __module_param_call_wdata(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0, data)
>
> Cryptic name. Moreover, inconsistent with the rest.
> What about module_param_cb_data() ?
>
> > #define module_param_cb_unsafe(name, ops, arg, perm) \
> > __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
> > KERNEL_PARAM_FL_UNSAFE)
>
> (above left for the above comment)
>
> ...
>
> > +#define __module_param_call_wdata(prefix, name, ops, arg, perm, level, flags, data) \
>
> Similar __module_param_call_with_data()
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

yes to all renames, revised.
thanks

2021-08-13 17:56:35

by Jim Cromie

[permalink] [raw]
Subject: Re: [PATCH v5 3/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks

> >
> > There is still plenty of bikeshedding to do.
>
> > ---
> > v4+:
> >
> > . rename to DEFINE_DYNAMIC_DEBUG_CATEGORIES from DEFINE_DYNDBG_BITMAP
> > . in query, replace hardcoded "i915" w kp->mod->name
> > . static inline the stubs
> > . const *str in structs, const array. -Emil
> > . dyndbg: add do-nothing DEFINE_DYNAMIC_DEBUG_CATEGORIES if !DD_CORE
> > . call MOD_PARM_DESC(name, "$desc") for users
> > . simplify callback, remove bit-change detection
> > . config errs reported by <[email protected]>
> >
> > ddh-helpers
>
> > Signed-off-by: Jim Cromie <[email protected]>
>
> So, it is signed or not? I didn't get (perhaps due to misplaced changlog?).
>

It might be my --- snip, and reliance on format-patch -s

would it work if I used -- 2char snip ?

> ...
>
> > } __attribute__((aligned(8)));
> >
> >
>
> Do we need two blank lines here?
>
> > +struct kernel_param;
>
> ...
>
> > +int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
> > +{
> > + unsigned long inbits;
> > + int rc, i, chgct = 0, totct = 0;
> > + char query[OUR_QUERY_SIZE];
> > + struct dyndbg_bitdesc *bitmap = (struct dyndbg_bitdesc *) kp->data;
>
> So you need space after ')' ?
>
> > + rc = kstrtoul(instr, 0, &inbits);
> > + if (rc) {
> > + pr_err("set_dyndbg: failed\n");
>
> > + return -EINVAL;
>
> Why not to return rc?
>
> > + }
> > + vpr_info("set_dyndbg: input 0x%lx\n", inbits);
> > +
> > + for (i = 0; !!bitmap[i].prefix; i++) {
>
> Hmm... Why not simply
>
> for (bitmap = ...; bitmap->prefix; bitmap++) {
>
> ?
>
> > +
>
> Redundant blank line.
>
> > + sprintf(query, "format '^%s' %cp", bitmap[i].prefix,
> > + test_bit(i, &inbits) ? '+' : '-');
>
> snprintf() ?
>
> > +
> > + chgct = dynamic_debug_exec_queries(query, kp->mod->name);
> > +
> > + v2pr_info("bit-%d: %d changes by '%s'\n", i, chgct, query);
> > + totct += chgct;
> > + }
> > + vpr_info("total changes: %d\n", totct);
> > + return 0;
> > +}
>
> ...
>
> > + return scnprintf(buffer, PAGE_SIZE, "%u\n",
> > + *((unsigned int *)kp->arg));
>
> One line.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

2021-08-13 19:37:27

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v5 3/9] dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks

On Fri, Aug 13, 2021 at 8:54 PM <[email protected]> wrote:
> > > There is still plenty of bikeshedding to do.
> >
> > > ---
> > > v4+:
> > >
> > > . rename to DEFINE_DYNAMIC_DEBUG_CATEGORIES from DEFINE_DYNDBG_BITMAP
> > > . in query, replace hardcoded "i915" w kp->mod->name
> > > . static inline the stubs
> > > . const *str in structs, const array. -Emil
> > > . dyndbg: add do-nothing DEFINE_DYNAMIC_DEBUG_CATEGORIES if !DD_CORE
> > > . call MOD_PARM_DESC(name, "$desc") for users
> > > . simplify callback, remove bit-change detection
> > > . config errs reported by <[email protected]>
> > >
> > > ddh-helpers
> >
> > > Signed-off-by: Jim Cromie <[email protected]>
> >
> > So, it is signed or not? I didn't get (perhaps due to misplaced changlog?).
> >
>
> It might be my --- snip, and reliance on format-patch -s
>
> would it work if I used -- 2char snip ?

The right thing to do is to have

SoB ...
'--- ' line
Changelog is _here_


--
With Best Regards,
Andy Shevchenko