perfctr ppc64 ABI update:
- <asm-ppc64/perfctr.h>: In user-visible state, make start fields
64 bits (for future-proofing the ABI). Remove map field from
pmc[] array to avoid underutilised cache lines.
- ppc64.c: retrieve mapping from ->control.pmc_map[].
- ppc64: Add sampling counter to user-visible state, and
increment it in perfctr_cpu_resume() and perfctr_cpu_sample().
Signed-off-by: Mikael Pettersson <[email protected]>
drivers/perfctr/ppc64.c | 16 ++++++++--------
include/asm-ppc64/perfctr.h | 13 ++++++++-----
2 files changed, 16 insertions(+), 13 deletions(-)
diff -rupN linux-2.6.12-rc2-mm2/drivers/perfctr/ppc64.c linux-2.6.12-rc2-mm2.perfctr-ppc64-update/drivers/perfctr/ppc64.c
--- linux-2.6.12-rc2-mm2/drivers/perfctr/ppc64.c 2005-04-08 13:14:23.000000000 +0200
+++ linux-2.6.12-rc2-mm2.perfctr-ppc64-update/drivers/perfctr/ppc64.c 2005-04-09 14:04:32.000000000 +0200
@@ -244,7 +244,7 @@ static void perfctr_cpu_read_counters(st
ctrs->tsc = mftb() & 0xffffffff;
for (i = 0; i < perfctr_cstatus_nractrs(cstatus); ++i) {
- pmc = state->user.pmc[i].map;
+ pmc = state->control.pmc_map[i];
ctrs->pmc[i] = read_pmc(pmc);
}
}
@@ -260,7 +260,7 @@ static void perfctr_cpu_isuspend(struct
cstatus = state->user.cstatus;
nrctrs = perfctr_cstatus_nrctrs(cstatus);
for (i = perfctr_cstatus_nractrs(cstatus); i < nrctrs; ++i) {
- unsigned int pmc = state->user.pmc[i].map;
+ unsigned int pmc = state->control.pmc_map[i];
unsigned int now = read_pmc(pmc);
state->user.pmc[i].sum += now - state->user.pmc[i].start;
@@ -299,7 +299,7 @@ static void perfctr_cpu_iresume(const st
cstatus = state->user.cstatus;
nrctrs = perfctr_cstatus_nrctrs(cstatus);
for (i = perfctr_cstatus_nractrs(cstatus); i < nrctrs; ++i) {
- write_pmc(state->user.pmc[i].map, state->user.pmc[i].start);
+ write_pmc(state->control.pmc_map[i], state->user.pmc[i].start);
}
}
@@ -334,7 +334,7 @@ unsigned int perfctr_cpu_identify_overfl
* amd unused PMCs as well as the ones we actually care
* about. */
for (i = 0; i < nractrs; ++i) {
- int pmc = state->user.pmc[i].map;
+ int pmc = state->control.pmc_map[i];
unsigned int val = read_pmc(pmc);
/* For actrs, force a sample if they overflowed */
@@ -347,7 +347,7 @@ unsigned int perfctr_cpu_identify_overfl
}
for (; i < nrctrs; ++i) {
if ((int)state->user.pmc[i].start < 0) { /* PPC64-specific */
- int pmc = state->user.pmc[i].map;
+ int pmc = state->control.pmc_map[i];
/* XXX: "+=" to correct for overshots */
state->user.pmc[i].start = state->control.ireset[pmc];
pmc_mask |= (1 << i);
@@ -376,7 +376,7 @@ static inline int check_ireset(struct pe
i = state->control.header.nractrs;
nrctrs = i + state->control.header.nrictrs;
for(; i < nrctrs; ++i) {
- unsigned int pmc = state->user.pmc[i].map;
+ unsigned int pmc = state->control.pmc_map[i];
if ((int)state->control.ireset[pmc] < 0) /* PPC64-specific */
return -EINVAL;
state->user.pmc[i].start = state->control.ireset[pmc];
@@ -406,7 +406,6 @@ static int check_control(struct perfctr_
pmc_mask = 0;
for (i = 0; i < nrctrs; ++i) {
pmc = state->control.pmc_map[i];
- state->user.pmc[i].map = pmc;
if (pmc >= nr_pmcs || (pmc_mask & (1<<pmc)))
return -EINVAL;
pmc_mask |= (1<<pmc);
@@ -571,7 +570,7 @@ void perfctr_cpu_resume(struct perfctr_c
for (i = 0; i < perfctr_cstatus_nractrs(cstatus); ++i)
state->user.pmc[i].start = now.pmc[i];
- /* XXX: if (SMP && start.tsc == now.tsc) ++now.tsc; */
+ ++state->user.samplecnt;
}
void perfctr_cpu_sample(struct perfctr_cpu_state *state)
@@ -590,6 +589,7 @@ void perfctr_cpu_sample(struct perfctr_c
state->user.pmc[i].sum += now.pmc[i] - state->user.pmc[i].start;
state->user.pmc[i].start = now.pmc[i];
}
+ ++state->user.samplecnt;
}
static void perfctr_cpu_clear_counters(void)
diff -rupN linux-2.6.12-rc2-mm2/include/asm-ppc64/perfctr.h linux-2.6.12-rc2-mm2.perfctr-ppc64-update/include/asm-ppc64/perfctr.h
--- linux-2.6.12-rc2-mm2/include/asm-ppc64/perfctr.h 2005-04-08 13:14:24.000000000 +0200
+++ linux-2.6.12-rc2-mm2.perfctr-ppc64-update/include/asm-ppc64/perfctr.h 2005-04-09 14:04:32.000000000 +0200
@@ -22,13 +22,16 @@ struct perfctr_cpu_control_header {
struct perfctr_cpu_state_user {
__u32 cstatus;
- /* The two tsc fields must be inlined. Placing them in a
- sub-struct causes unwanted internal padding on x86-64. */
- __u32 tsc_start;
+ /* 'samplecnt' is incremented every time the 'start'
+ fields have been updated by a sampling operation.
+ Unfortunately the PPC timebase (tsc_start) has too
+ low frequency for it to be a reliable context-switch
+ indicator for user-space. */
+ __u32 samplecnt;
+ __u64 tsc_start;
__u64 tsc_sum;
struct {
- __u32 map;
- __u32 start;
+ __u64 start;
__u64 sum;
} pmc[8]; /* the size is not part of the user ABI */
};