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| author | Madhavan Srinivasan <maddy@linux.vnet.ibm.com> | 2017-02-12 20:03:14 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-02-17 13:48:54 +0300 |
| commit | 356d8ce3d0a4a1d7c8448c4d234121736ad3d471 (patch) | |
| tree | 5f35c712ee9a717caae8fc863f1381cf3a440cc4 /arch | |
| parent | 8a088542c8f8d0bb458e4db2c01a2534f1adaf47 (diff) | |
| download | linux-356d8ce3d0a4a1d7c8448c4d234121736ad3d471.tar.xz | |
powerpc/perf: Use Instruction Counter value
Since PM_INST_DISP include speculative instruction,
based on the workload the dispatch count could vary
considerably. Hence as an alternative, for completed
instruction counting, program the PM_INST_DISP event
to the MMCR* but use Instruction Counter register value.
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 270eb9b74e2e..87d17a1f7168 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -57,6 +57,7 @@ struct cpu_hw_events { void *bhrb_context; struct perf_branch_stack bhrb_stack; struct perf_branch_entry bhrb_entries[BHRB_MAX_ENTRIES]; + u64 ic_init; }; static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); @@ -127,6 +128,10 @@ static inline void power_pmu_bhrb_disable(struct perf_event *event) {} static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) {} static inline void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) {} static void pmao_restore_workaround(bool ebb) { } +static bool use_ic(u64 event) +{ + return false; +} #endif /* CONFIG_PPC32 */ static bool regs_use_siar(struct pt_regs *regs) @@ -688,6 +693,15 @@ static void pmao_restore_workaround(bool ebb) mtspr(SPRN_PMC5, pmcs[4]); mtspr(SPRN_PMC6, pmcs[5]); } + +static bool use_ic(u64 event) +{ + if (cpu_has_feature(CPU_FTR_POWER9_DD1) && + (event == 0x200f2 || event == 0x300f2)) + return true; + + return false; +} #endif /* CONFIG_PPC64 */ static void perf_event_interrupt(struct pt_regs *regs); @@ -1007,6 +1021,7 @@ static u64 check_and_compute_delta(u64 prev, u64 val) static void power_pmu_read(struct perf_event *event) { s64 val, delta, prev; + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); if (event->hw.state & PERF_HES_STOPPED) return; @@ -1016,6 +1031,13 @@ static void power_pmu_read(struct perf_event *event) if (is_ebb_event(event)) { val = read_pmc(event->hw.idx); + if (use_ic(event->attr.config)) { + val = mfspr(SPRN_IC); + if (val > cpuhw->ic_init) + val = val - cpuhw->ic_init; + else + val = val + (0 - cpuhw->ic_init); + } local64_set(&event->hw.prev_count, val); return; } @@ -1029,6 +1051,13 @@ static void power_pmu_read(struct perf_event *event) prev = local64_read(&event->hw.prev_count); barrier(); val = read_pmc(event->hw.idx); + if (use_ic(event->attr.config)) { + val = mfspr(SPRN_IC); + if (val > cpuhw->ic_init) + val = val - cpuhw->ic_init; + else + val = val + (0 - cpuhw->ic_init); + } delta = check_and_compute_delta(prev, val); if (!delta) return; @@ -1466,6 +1495,13 @@ nocheck: event->attr.branch_sample_type); } + /* + * Workaround for POWER9 DD1 to use the Instruction Counter + * register value for instruction counting + */ + if (use_ic(event->attr.config)) + cpuhw->ic_init = mfspr(SPRN_IC); + perf_pmu_enable(event->pmu); local_irq_restore(flags); return ret; |