Subject: [PATCH 0/10] oprofile and ftrace: some trivial patches

The following patch set contains some cleanups, code reworks and fixes
for oprofile. Additional there are 2 trivial patches for ftrace
too. This patch set is in preparation of a follow on patch set that
ports to the new ring buffer.

Patches are also here:

git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile.git next

-Robert



Subject: [PATCH 04/10] oprofile: fix typo

Signed-off-by: Robert Richter <[email protected]>
---
drivers/oprofile/buffer_sync.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index b55cd23..774b081 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -272,7 +272,7 @@ static void increment_tail(struct oprofile_cpu_buffer *b)
{
unsigned long new_tail = b->tail_pos + 1;

- rmb(); /* be sure fifo pointers are synchromized */
+ rmb(); /* be sure fifo pointers are synchronized */

if (new_tail < b->buffer_size)
b->tail_pos = new_tail;
--
1.6.0.1

Subject: [PATCH 01/10] oprofile: comment cleanup

This fixes the coding style of some comments.

Signed-off-by: Robert Richter <[email protected]>
---
arch/x86/oprofile/op_model_amd.c | 31 ++++++++++++++++---------------
drivers/oprofile/cpu_buffer.c | 25 ++++++++++++++++---------
2 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 5095137..fb67e19 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -65,8 +65,10 @@ static unsigned long reset_value[NUM_COUNTERS];
#define IBS_FETCH_BEGIN 3
#define IBS_OP_BEGIN 4

-/* The function interface needs to be fixed, something like add
- data. Should then be added to linux/oprofile.h. */
+/*
+ * The function interface needs to be fixed, something like add
+ * data. Should then be added to linux/oprofile.h.
+ */
extern void
oprofile_add_ibs_sample(struct pt_regs *const regs,
unsigned int *const ibs_sample, int ibs_code);
@@ -106,7 +108,7 @@ struct ibs_op_sample {

/*
* unitialize the APIC for the IBS interrupts if needed on AMD Family10h+
-*/
+ */
static void clear_ibs_nmi(void);

static int ibs_allowed; /* AMD Family10h and later */
@@ -223,7 +225,7 @@ op_amd_handle_ibs(struct pt_regs * const regs,
(unsigned int *)&ibs_fetch,
IBS_FETCH_BEGIN);

- /*reenable the IRQ */
+ /* reenable the IRQ */
rdmsr(MSR_AMD64_IBSFETCHCTL, low, high);
high &= ~IBS_FETCH_HIGH_VALID_BIT;
high |= IBS_FETCH_HIGH_ENABLE;
@@ -331,8 +333,10 @@ static void op_amd_stop(struct op_msrs const * const msrs)
unsigned int low, high;
int i;

- /* Subtle: stop on all counters to avoid race with
- * setting our pm callback */
+ /*
+ * Subtle: stop on all counters to avoid race with setting our
+ * pm callback
+ */
for (i = 0 ; i < NUM_COUNTERS ; ++i) {
if (!reset_value[i])
continue;
@@ -343,13 +347,15 @@ static void op_amd_stop(struct op_msrs const * const msrs)

#ifdef CONFIG_OPROFILE_IBS
if (ibs_allowed && ibs_config.fetch_enabled) {
- low = 0; /* clear max count and enable */
+ /* clear max count and enable */
+ low = 0;
high = 0;
wrmsr(MSR_AMD64_IBSFETCHCTL, low, high);
}

if (ibs_allowed && ibs_config.op_enabled) {
- low = 0; /* clear max count and enable */
+ /* clear max count and enable */
+ low = 0;
high = 0;
wrmsr(MSR_AMD64_IBSOPCTL, low, high);
}
@@ -443,10 +449,7 @@ static int pfm_amd64_setup_eilvt(void)
return 0;
}

-/*
- * initialize the APIC for the IBS interrupts
- * if available (AMD Family10h rev B0 and later)
- */
+/* initialize the APIC for the IBS interrupts if available */
static void setup_ibs(void)
{
ibs_allowed = boot_cpu_has(X86_FEATURE_IBS);
@@ -463,9 +466,7 @@ static void setup_ibs(void)
}


-/*
- * unitialize the APIC for the IBS interrupts if needed on AMD Family10h
- * rev B0 and later */
+/* uninitialize the APIC for the IBS interrupts if needed */
static void clear_ibs_nmi(void)
{
if (ibs_allowed)
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 01d38e7..3958107 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -127,9 +127,10 @@ void end_cpu_work(void)
/* Resets the cpu buffer to a sane state. */
void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf)
{
- /* reset these to invalid values; the next sample
- * collected will populate the buffer with proper
- * values to initialize the buffer
+ /*
+ * reset these to invalid values; the next sample collected
+ * will populate the buffer with proper values to initialize
+ * the buffer
*/
cpu_buf->last_is_kernel = -1;
cpu_buf->last_task = NULL;
@@ -151,8 +152,10 @@ static void increment_head(struct oprofile_cpu_buffer *b)
{
unsigned long new_head = b->head_pos + 1;

- /* Ensure anything written to the slot before we
- * increment is visible */
+ /*
+ * Ensure anything written to the slot before we increment is
+ * visible
+ */
wmb();

if (new_head < b->buffer_size)
@@ -253,8 +256,10 @@ void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
if (!oprofile_begin_trace(cpu_buf))
return;

- /* if log_sample() fail we can't backtrace since we lost the source
- * of this event */
+ /*
+ * if log_sample() fail we can't backtrace since we lost the
+ * source of this event
+ */
if (log_sample(cpu_buf, pc, is_kernel, event))
oprofile_ops.backtrace(regs, backtrace_depth);
oprofile_end_trace(cpu_buf);
@@ -338,8 +343,10 @@ void oprofile_add_trace(unsigned long pc)
return;
}

- /* broken frame can give an eip with the same value as an escape code,
- * abort the trace if we get it */
+ /*
+ * broken frame can give an eip with the same value as an
+ * escape code, abort the trace if we get it
+ */
if (pc == ESCAPE_CODE) {
cpu_buf->tracing = 0;
cpu_buf->backtrace_aborted++;
--
1.6.0.1

Subject: [PATCH 10/10] ftrace: remove unused function arg in trace_iterator_increment()

This removes the unused cpu function parameter.

Cc: Steven Rostedt <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
---
kernel/trace/trace.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d86e325..a96b335 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -914,7 +914,7 @@ enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
};

-static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
+static void trace_iterator_increment(struct trace_iterator *iter)
{
/* Don't allow ftrace to trace into the ring buffers */
ftrace_disable_cpu();
@@ -993,7 +993,7 @@ static void *find_next_entry_inc(struct trace_iterator *iter)
iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);

if (iter->ent)
- trace_iterator_increment(iter, iter->cpu);
+ trace_iterator_increment(iter);

return iter->ent ? iter : NULL;
}
--
1.6.0.1

Subject: [PATCH 03/10] oprofile: whitspace changes only

Signed-off-by: Robert Richter <[email protected]>
---
arch/x86/oprofile/op_model_amd.c | 4 ++--
drivers/oprofile/cpu_buffer.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index fb67e19..f71bd21 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -70,8 +70,8 @@ static unsigned long reset_value[NUM_COUNTERS];
* data. Should then be added to linux/oprofile.h.
*/
extern void
-oprofile_add_ibs_sample(struct pt_regs *const regs,
- unsigned int *const ibs_sample, int ibs_code);
+oprofile_add_ibs_sample(struct pt_regs * const regs,
+ unsigned int * const ibs_sample, int ibs_code);

struct ibs_fetch_sample {
/* MSRC001_1031 IBS Fetch Linear Address Register */
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 3958107..2c4d541 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -277,8 +277,8 @@ void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)

#define MAX_IBS_SAMPLE_SIZE 14

-void oprofile_add_ibs_sample(struct pt_regs *const regs,
- unsigned int *const ibs_sample, int ibs_code)
+void oprofile_add_ibs_sample(struct pt_regs * const regs,
+ unsigned int * const ibs_sample, int ibs_code)
{
int is_kernel = !user_mode(regs);
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(cpu_buffer);
--
1.6.0.1

Subject: [PATCH 08/10] oprofile: set values to default when creating oprofilefs

This patch restores default values for:

/dev/oprofile/cpu_buffer_size
/dev/oprofile/buffer_watershed
/dev/oprofile/buffer_size

when creating the oprofilefs:

# opcontrol --deinit
# opcontrol --init
# cat /dev/oprofile/cpu_buffer_size
8192
# echo 5123 > /dev/oprofile/cpu_buffer_size
# cat /dev/oprofile/cpu_buffer_size
5123
# opcontrol --deinit
# opcontrol --init
# cat /dev/oprofile/cpu_buffer_size
8192
# opcontrol --deinit

This sets the values in a defined state. Before, there was no way to
restore the defaults without rebooting the system or reloading the
module.

Signed-off-by: Robert Richter <[email protected]>
---
drivers/oprofile/oprofile_files.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c
index cc106d5..d820199 100644
--- a/drivers/oprofile/oprofile_files.c
+++ b/drivers/oprofile/oprofile_files.c
@@ -14,9 +14,13 @@
#include "oprofile_stats.h"
#include "oprof.h"

-unsigned long fs_buffer_size = 131072;
-unsigned long fs_cpu_buffer_size = 8192;
-unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
+#define FS_BUFFER_SIZE_DEFAULT 131072
+#define FS_CPU_BUFFER_SIZE_DEFAULT 8192
+#define FS_BUFFER_WATERSHED_DEFAULT 32768 /* FIXME: tune */
+
+unsigned long fs_buffer_size;
+unsigned long fs_cpu_buffer_size;
+unsigned long fs_buffer_watershed;

static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
@@ -120,6 +124,11 @@ static const struct file_operations dump_fops = {

void oprofile_create_files(struct super_block *sb, struct dentry *root)
{
+ /* reinitialize default values */
+ fs_buffer_size = FS_BUFFER_SIZE_DEFAULT;
+ fs_cpu_buffer_size = FS_CPU_BUFFER_SIZE_DEFAULT;
+ fs_buffer_watershed = FS_BUFFER_WATERSHED_DEFAULT;
+
oprofilefs_create_file(sb, root, "enable", &enable_fops);
oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
--
1.6.0.1

Subject: [PATCH 09/10] ring_buffer: update description for ring_buffer_alloc()

Trivial patch.

Cc: Steven Rostedt <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
---
kernel/trace/ring_buffer.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 668bbb5..c8996d2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -381,7 +381,7 @@ extern int ring_buffer_page_too_big(void);

/**
* ring_buffer_alloc - allocate a new ring_buffer
- * @size: the size in bytes that is needed.
+ * @size: the size in bytes per cpu that is needed.
* @flags: attributes to set for the ring buffer.
*
* Currently the only flag that is available is the RB_FL_OVERWRITE
--
1.6.0.1

Subject: [PATCH 02/10] oprofile: update comment for oprofile_add_sample()

The cpu argument is no longer part of the parameter list.

Signed-off-by: Robert Richter <[email protected]>
---
include/linux/oprofile.h | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h
index 5231861..1ce9fe5 100644
--- a/include/linux/oprofile.h
+++ b/include/linux/oprofile.h
@@ -86,8 +86,7 @@ int oprofile_arch_init(struct oprofile_operations * ops);
void oprofile_arch_exit(void);

/**
- * Add a sample. This may be called from any context. Pass
- * smp_processor_id() as cpu.
+ * Add a sample. This may be called from any context.
*/
void oprofile_add_sample(struct pt_regs * const regs, unsigned long event);

--
1.6.0.1

Subject: [PATCH 06/10] x86/oprofile: cleanup IBS init/exit functions in op_model_amd.c

Implementation of pairwise init/exit funcions for IBS and IBS NMI
setup. There are also some function renames and the removal of forward
function declarations.

Signed-off-by: Robert Richter <[email protected]>
---
arch/x86/oprofile/op_model_amd.c | 32 +++++++++++++++++---------------
1 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 8ff657b..98658f2 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -106,11 +106,6 @@ struct ibs_op_sample {
unsigned int ibs_dc_phys_high;
};

-/*
- * unitialize the APIC for the IBS interrupts if needed on AMD Family10h+
- */
-static void clear_ibs_nmi(void);
-
static int ibs_allowed; /* AMD Family10h and later */

struct op_ibs_config {
@@ -390,7 +385,7 @@ static inline void apic_clear_ibs_nmi_per_cpu(void *arg)
setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_FIX, 1);
}

-static int pfm_amd64_setup_eilvt(void)
+static int init_ibs_nmi(void)
{
#define IBSCTL_LVTOFFSETVAL (1 << 8)
#define IBSCTL 0x1cc
@@ -438,15 +433,22 @@ static int pfm_amd64_setup_eilvt(void)
return 0;
}

+/* uninitialize the APIC for the IBS interrupts if needed */
+static void clear_ibs_nmi(void)
+{
+ if (ibs_allowed)
+ on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1);
+}
+
/* initialize the APIC for the IBS interrupts if available */
-static void setup_ibs(void)
+static void ibs_init(void)
{
ibs_allowed = boot_cpu_has(X86_FEATURE_IBS);

if (!ibs_allowed)
return;

- if (pfm_amd64_setup_eilvt()) {
+ if (init_ibs_nmi()) {
ibs_allowed = 0;
return;
}
@@ -454,12 +456,12 @@ static void setup_ibs(void)
printk(KERN_INFO "oprofile: AMD IBS detected\n");
}

-
-/* uninitialize the APIC for the IBS interrupts if needed */
-static void clear_ibs_nmi(void)
+static void ibs_exit(void)
{
- if (ibs_allowed)
- on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1);
+ if (!ibs_allowed)
+ return;
+
+ clear_ibs_nmi();
}

static int (*create_arch_files)(struct super_block *sb, struct dentry *root);
@@ -509,7 +511,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)

static int op_amd_init(struct oprofile_operations *ops)
{
- setup_ibs();
+ ibs_init();
create_arch_files = ops->create_files;
ops->create_files = setup_ibs_files;
return 0;
@@ -517,7 +519,7 @@ static int op_amd_init(struct oprofile_operations *ops)

static void op_amd_exit(void)
{
- clear_ibs_nmi();
+ ibs_exit();
}

#else
--
1.6.0.1

Subject: [PATCH 05/10] x86/oprofile: reordering IBS code in op_model_amd.c

This is part of the cpu buffer rework.

Signed-off-by: Robert Richter <[email protected]>
---
arch/x86/oprofile/op_model_amd.c | 26 +++++++++++++-------------
1 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index f71bd21..8ff657b 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -376,18 +376,7 @@ static void op_amd_shutdown(struct op_msrs const * const msrs)
}
}

-#ifndef CONFIG_OPROFILE_IBS
-
-/* no IBS support */
-
-static int op_amd_init(struct oprofile_operations *ops)
-{
- return 0;
-}
-
-static void op_amd_exit(void) {}
-
-#else
+#ifdef CONFIG_OPROFILE_IBS

static u8 ibs_eilvt_off;

@@ -531,7 +520,18 @@ static void op_amd_exit(void)
clear_ibs_nmi();
}

-#endif
+#else
+
+/* no IBS support */
+
+static int op_amd_init(struct oprofile_operations *ops)
+{
+ return 0;
+}
+
+static void op_amd_exit(void) {}
+
+#endif /* CONFIG_OPROFILE_IBS */

struct op_x86_model_spec const op_amd_spec = {
.init = op_amd_init,
--
1.6.0.1

Subject: [PATCH 07/10] oprofile: implement switch/case in buffer_sync.c

Signed-off-by: Robert Richter <[email protected]>
---
drivers/oprofile/buffer_sync.c | 22 ++++++++++++++--------
1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 774b081..7d61ae8 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -561,6 +561,7 @@ void sync_buffer(int cpu)
{
struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
struct mm_struct *mm = NULL;
+ struct mm_struct *oldmm;
struct task_struct *new;
unsigned long cookie = 0;
int in_kernel = 1;
@@ -586,34 +587,39 @@ void sync_buffer(int cpu)
struct op_sample *s = &cpu_buf->buffer[cpu_buf->tail_pos];

if (is_code(s->eip)) {
- if (s->event <= CPU_IS_KERNEL) {
+ switch (s->event) {
+ case 0:
+ case CPU_IS_KERNEL:
/* kernel/userspace switch */
in_kernel = s->event;
if (state == sb_buffer_start)
state = sb_sample_start;
add_kernel_ctx_switch(s->event);
- } else if (s->event == CPU_TRACE_BEGIN) {
+ break;
+ case CPU_TRACE_BEGIN:
state = sb_bt_start;
add_trace_begin();
+ break;
#ifdef CONFIG_OPROFILE_IBS
- } else if (s->event == IBS_FETCH_BEGIN) {
+ case IBS_FETCH_BEGIN:
state = sb_bt_start;
add_ibs_begin(cpu_buf, IBS_FETCH_CODE, mm);
- } else if (s->event == IBS_OP_BEGIN) {
+ break;
+ case IBS_OP_BEGIN:
state = sb_bt_start;
add_ibs_begin(cpu_buf, IBS_OP_CODE, mm);
+ break;
#endif
- } else {
- struct mm_struct *oldmm = mm;
-
+ default:
/* userspace context switch */
+ oldmm = mm;
new = (struct task_struct *)s->event;
-
release_mm(oldmm);
mm = take_tasks_mm(new);
if (mm != oldmm)
cookie = get_exec_dcookie(mm);
add_user_ctx_switch(new, cookie);
+ break;
}
} else if (state >= sb_bt_start &&
!add_sample(mm, s, in_kernel)) {
--
1.6.0.1

2008-12-16 09:32:54

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 08/10] oprofile: set values to default when creating oprofilefs

On Thu, 11 Dec 2008 16:04:44 +0100 Robert Richter <[email protected]> wrote:

> This patch restores default values for:
>
> /dev/oprofile/cpu_buffer_size
> /dev/oprofile/buffer_watershed
> /dev/oprofile/buffer_size
>
> when creating the oprofilefs:
>
> # opcontrol --deinit
> # opcontrol --init
> # cat /dev/oprofile/cpu_buffer_size
> 8192
> # echo 5123 > /dev/oprofile/cpu_buffer_size
> # cat /dev/oprofile/cpu_buffer_size
> 5123
> # opcontrol --deinit
> # opcontrol --init
> # cat /dev/oprofile/cpu_buffer_size
> 8192
> # opcontrol --deinit
>
> This sets the values in a defined state. Before, there was no way to
> restore the defaults without rebooting the system or reloading the
> module.
>
> Signed-off-by: Robert Richter <[email protected]>
> ---
> drivers/oprofile/oprofile_files.c | 15 ++++++++++++---
> 1 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c
> index cc106d5..d820199 100644
> --- a/drivers/oprofile/oprofile_files.c
> +++ b/drivers/oprofile/oprofile_files.c
> @@ -14,9 +14,13 @@
> #include "oprofile_stats.h"
> #include "oprof.h"
>
> -unsigned long fs_buffer_size = 131072;
> -unsigned long fs_cpu_buffer_size = 8192;
> -unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
> +#define FS_BUFFER_SIZE_DEFAULT 131072
> +#define FS_CPU_BUFFER_SIZE_DEFAULT 8192
> +#define FS_BUFFER_WATERSHED_DEFAULT 32768 /* FIXME: tune */
> +
> +unsigned long fs_buffer_size;
> +unsigned long fs_cpu_buffer_size;
> +unsigned long fs_buffer_watershed;

These were poorly chosen kernel-wide identifiers.

> static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
> {
> @@ -120,6 +124,11 @@ static const struct file_operations dump_fops = {
>
> void oprofile_create_files(struct super_block *sb, struct dentry *root)
> {
> + /* reinitialize default values */
> + fs_buffer_size = FS_BUFFER_SIZE_DEFAULT;
> + fs_cpu_buffer_size = FS_CPU_BUFFER_SIZE_DEFAULT;
> + fs_buffer_watershed = FS_BUFFER_WATERSHED_DEFAULT;
> +
> oprofilefs_create_file(sb, root, "enable", &enable_fops);
> oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
> oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);

afacit oprofile_create_files() only gets run when the module is loaded,
so this patch is a no-op?

Subject: Re: [PATCH 08/10] oprofile: set values to default when creating oprofilefs

On 16.12.08 01:32:25, Andrew Morton wrote:
> > +unsigned long fs_buffer_size;
> > +unsigned long fs_cpu_buffer_size;
> > +unsigned long fs_buffer_watershed;
>
> These were poorly chosen kernel-wide identifiers.

Right, didn't notice that. Will change this.

> > static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
> > {
> > @@ -120,6 +124,11 @@ static const struct file_operations dump_fops = {
> >
> > void oprofile_create_files(struct super_block *sb, struct dentry *root)
> > {
> > + /* reinitialize default values */
> > + fs_buffer_size = FS_BUFFER_SIZE_DEFAULT;
> > + fs_cpu_buffer_size = FS_CPU_BUFFER_SIZE_DEFAULT;
> > + fs_buffer_watershed = FS_BUFFER_WATERSHED_DEFAULT;
> > +
> > oprofilefs_create_file(sb, root, "enable", &enable_fops);
> > oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
> > oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
>
> afacit oprofile_create_files() only gets run when the module is loaded,
> so this patch is a no-op?

This code runs when oprofilefs is mounted. This happens typically in
an opcontrol --init/--deinit sequence. Before, the previous values
would have been used after mounting again. Now, default values are
restored.

-Robert

--
Advanced Micro Devices, Inc.
Operating System Research Center
email: [email protected]