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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-04-22 13:39:56 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-04-22 13:50:27 +0200 |
| commit | f4929bd37208540c2c6f416e9035ff1938f2dbc6 (patch) | |
| tree | 307e058a47993c91d806f8c7bb505e8afe778a27 /arch/x86 | |
| parent | 1ea5a6afd95a4803900c97ed63a47a883ebe7b3e (diff) | |
| download | linux-f4929bd37208540c2c6f416e9035ff1938f2dbc6.tar.gz linux-f4929bd37208540c2c6f416e9035ff1938f2dbc6.tar.bz2 linux-f4929bd37208540c2c6f416e9035ff1938f2dbc6.zip | |
perf, x86: Update/fix Intel Nehalem cache events
Change the Nehalem cache events to use retired memory instruction counters
(similar to Westmere), this greatly improves the provided stats.
Using:
main ()
{
int i;
for (i = 0; i < 1000000000; i++) {
asm("mov (%%rsp), %%rbx;"
"mov %%rbx, (%%rsp);" : : : "rbx");
}
}
We find:
$ perf stat --repeat 10 -e instructions:u -e l1-dcache-loads:u -e l1-dcache-stores:u ./loop_1b_loads+stores
Performance counter stats for './loop_1b_loads+stores' (10 runs):
4,000,081,056 instructions:u # 0.000 IPC ( +- 0.000% )
4,999,502,846 l1-dcache-loads:u ( +- 0.008% )
1,000,034,832 l1-dcache-stores:u ( +- 0.000% )
1.565184942 seconds time elapsed ( +- 0.005% )
The 5b is surprising - we'd expect 1b:
$ perf stat --repeat 10 -e instructions:u -e r10b:u -e l1-dcache-stores:u ./loop_1b_loads+stores
Performance counter stats for './loop_1b_loads+stores' (10 runs):
4,000,081,054 instructions:u # 0.000 IPC ( +- 0.000% )
1,000,021,961 r10b:u ( +- 0.000% )
1,000,030,951 l1-dcache-stores:u ( +- 0.000% )
1.565055422 seconds time elapsed ( +- 0.003% )
Which this patch thus fixes.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/n/tip-q9rtru7b7840tws75xzboapv@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 586cced12d1f..43fa20b13817 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -391,12 +391,12 @@ static __initconst const u64 nehalem_hw_cache_event_ids { [ C(L1D) ] = { [ C(OP_READ) ] = { - [ C(RESULT_ACCESS) ] = 0x0f40, /* L1D_CACHE_LD.MESI */ - [ C(RESULT_MISS) ] = 0x0140, /* L1D_CACHE_LD.I_STATE */ + [ C(RESULT_ACCESS) ] = 0x010b, /* MEM_INST_RETIRED.LOADS */ + [ C(RESULT_MISS) ] = 0x0151, /* L1D.REPL */ }, [ C(OP_WRITE) ] = { - [ C(RESULT_ACCESS) ] = 0x0f41, /* L1D_CACHE_ST.MESI */ - [ C(RESULT_MISS) ] = 0x0141, /* L1D_CACHE_ST.I_STATE */ + [ C(RESULT_ACCESS) ] = 0x020b, /* MEM_INST_RETURED.STORES */ + [ C(RESULT_MISS) ] = 0x0251, /* L1D.M_REPL */ }, [ C(OP_PREFETCH) ] = { [ C(RESULT_ACCESS) ] = 0x014e, /* L1D_PREFETCH.REQUESTS */ |