Messages in this thread | | | Date | Tue, 6 Nov 2012 16:49:26 +0100 | Subject | Re: [PATCH v2 14/16] perf tools: add new mem command for memory access profiling | From | Stephane Eranian <> |
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On Tue, Nov 6, 2012 at 4:44 PM, Arnaldo Carvalho de Melo <acme@redhat.com> wrote: > 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: > That's because you need to update the microcode.
$ sudo modprobe microcode $ cat /proc/cpuinfo
Line with microcode needs to say: microcode : 0x28
update the microcode package or install directly from intel download center.
> [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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