Messages in this thread | | | Date | Tue, 6 Nov 2012 12:44:46 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2 14/16] perf tools: add new mem command for memory access profiling |
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Em Mon, Nov 05, 2012 at 02:51:01PM +0100, Stephane Eranian escreveu: > + > + if (strcmp(mem_operation, MEM_OPERATION_LOAD)) > + sprintf(event, "cpu/mem-stores/pp"); > + else > + sprintf(event, "cpu/mem-loads/pp"); > +
Fails for me on a Sandy Bridge notebook:
[root@sandy ~]# perf mem -t store record -a Error: 'precise' request may not be supported. Try removing 'p' modifier
So if I manually fall back to a less precise mode:
[root@sandy ~]# perf record -g -a -e cpu/mem-stores/p Error: 'precise' request may not be supported. Try removing 'p' modifier [root@sandy ~]#
Still can't, manually fall back a one more level:
[root@sandy ~]# perf record -g -a -e cpu/mem-stores/ ^C[ perf record: Woken up 25 times to write data ] [ perf record: Captured and wrote 7.419 MB perf.data (~324160 samples) ]
Yay, got some numbers.
smpboot: CPU0: Intel(R) Core(TM) i7-2920XM CPU @ 2.50GHz (fam: 06, model: 2a, stepping: 07) Performance Events: PEBS fmt1+, 16-deep LBR, SandyBridge events, Intel PMU driver. perf_event_intel: PEBS disabled due to CPU errata, please upgrade microcode ... version: 3 ... bit width: 48 ... generic registers: 4 ... value mask: 0000ffffffffffff ... max period: 000000007fffffff ... fixed-purpose events: 3 ... event mask: 000000070000000f Disabled fast string operations NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
Do you have any test program you use to test if the results make sense that you could share?
I could then try to shape it into a new 'perf test' entry that would test if requesting this event and then doing synthetic testing would produce the experted numbers or in a acceptable range.
One suggestion for such new features, examples of use with the resulting output looks great on changeset logs :-)
Ah, I recall seeing some, but that was on the patchset cover letter, that doesn't get inserted in the git changelog history, will look at those now.
- Arnaldo
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