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SubjectRe: [PATCH v2 14/16] perf tools: add new mem command for memory access profiling
Em Tue, Nov 06, 2012 at 04:57:59PM +0100, Stephane Eranian escreveu:
> On Tue, Nov 6, 2012 at 4:50 PM, Arnaldo Carvalho de Melo
> <acme@ghostprotocols.net> wrote:
> > Em Tue, Nov 06, 2012 at 12:44:46PM -0300, Arnaldo Carvalho de Melo escreveu:
> >> [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.
> >
> > But then the results out of:
> >
> > $ perf mem -t load rep --stdio
> >
> > Are bogus at least on the callchains:
> >
> I think it's because we are not using the period in the hist_entry but
> the cost and there
> is no cost for stores.
>
> I think you should start with loads and no callchain. I am interested
> in your toughts on how to
> fix the data symbol resolution problem in perf. In V2, I modified the
> kernel to at least
> help perf distinguish MAP__FUNCTION from MAP__VARIABLE. But there is
> still something
> wrong.

Yeah, I saw that, now that I'm playing with this patchset I'll work on
that, after lunch.

>
> > # ========
> > # captured on: Tue Nov 6 12:46:21 2012
> > # hostname : sandy.ghostprotocols.net
> > # os release : 3.7.0-rc2+
> > # perf version : 3.7.rc4.gfaa41f
> > # arch : x86_64
> > # nrcpus online : 8
> > # nrcpus avail : 8
> > # cpudesc : Intel(R) Core(TM) i7-2920XM CPU @ 2.50GHz
> > # cpuid : GenuineIntel,6,42,7
> > # total memory : 16220228 kB
> > # cmdline : /home/acme/bin/perf record -g -a -e cpu/mem-stores/
> > # event : name = cpu/mem-stores/, type = 4, config = 0x2cd, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, excl_ho
> > # HEADER_CPU_TOPOLOGY info available, use -I to display
> > # HEADER_NUMA_TOPOLOGY info available, use -I to display
> > # pmu mappings: cpu = 4, software = 1, tracepoint = 2, uncore_cbox_0 = 6, uncore_cbox_1 = 7, uncore_cbox_2 = 8, uncore_cbox_3
> > # ========
> > #
> > # Samples: 98 of event 'cpu/mem-stores/'
> > # Total cost : 98
> > # Sort order : cost,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked
> > #
> > # Overhead Samples Cost Memory access Symbol Share
> > # ........ ........... ....... ........................ .............................................. ..................
> > #
> > 19.39% 19 N/A [k] csd_unlock [kernel.kallsyms]
> > |
> > --- csd_unlock
> > |
> > |--6242.11%-- generic_smp_call_function_single_interrupt
> > | smp_call_function_single_interrupt
> > | call_function_single_interrupt
> > | cpuidle_enter
> > | cpuidle_enter_state
> > | cpuidle_idle_call
> > | cpu_idle
> > | |
> > | |--85.08%-- start_secondary
> > | |
> > | --14.92%-- rest_init
> > | start_kernel
> > | x86_64_start_reservations
> > | x86_64_start_kernel
> > |
> > |--100.00%-- smp_call_function_single_interrupt
> > | call_function_single_interrupt
> > | cpuidle_enter
> > | cpuidle_enter_state
> > | cpuidle_idle_call
> > | cpu_idle
> > | start_secondary
> > --97088126703734472704.00%-- [...]
> >
> > 5.10% 5 N/A [k] _raw_spin_lock_irqsave [kernel.kallsyms]
> > |
> >
> >
> >
> > Ideas?
> >
> > - Arnaldo


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