Re: [PATCH V8 08/25] perf tools: Add Intel BTS support
From: Adrian Hunter
Date: Tue Aug 18 2015 - 02:42:56 EST
On 17/08/15 22:58, Arnaldo Carvalho de Melo wrote:
> Em Mon, Aug 17, 2015 at 10:09:26PM +0300, Adrian Hunter escreveu:
>> On 17/08/2015 8:58 p.m., Arnaldo Carvalho de Melo wrote:
>>> Em Mon, Aug 17, 2015 at 08:43:09PM +0300, Adrian Hunter escreveu:
>>>> On 17/08/2015 6:52 p.m., Arnaldo Carvalho de Melo wrote:
>>>>> 1.92% usleep [unknown] [.] 0x00007fa0ff695086
>>>>> 1.60% usleep [unknown] [.] 0xffffffff811c91d0
>>>>> 1.48% usleep [unknown] [.] 0x00007fa0ffb3030d
>>>>> 1.24% usleep [unknown] [.] 0x00007fa0ff6950c7
>>>
>>>> It is very weird that it doesn't know the dso.
>>>
>>>> I presume there is nothing unusual about the environment e.g. in a chroot or anything
>>>
>>>> What if you try a different event e.g. perf record --per-thread -e cycles sleep 1
>>>
>>> [root@zoo ~]# perf record --per-thread -e cycles sleep 1
>>> [ perf record: Woken up 1 times to write data ]
>>> [ perf record: Captured and wrote 0.014 MB perf.data (9 samples) ]
>>> [root@zoo ~]# perf report | grep -v ^# | head -5
>>> 42.57% sleep libc-2.20.so [.] malloc_hook_ini
>>> 41.81% sleep [kernel.vmlinux] [k] filemap_fault
>>> 14.35% sleep [kernel.vmlinux] [k] flush_tlb_mm_range
>>> 1.18% sleep [kernel.vmlinux] [k] strlcpy
>>> 0.09% sleep [kernel.vmlinux] [k] native_write_msr_safe
>>> [root@zoo ~]#
>>>
>>> [root@zoo ~]# perf report --dsos libc-2.20.so | grep -v '^[#]'
>>> 42.57% sleep [.] malloc_hook_ini
>>>
>>> [root@zoo ~]#
>>>
>>> [root@zoo ~]# perf record --per-thread -e intel_bts// usleep 1
>>> [ perf record: Woken up 1 times to write data ]
>>> [ perf record: Captured and wrote 1.825 MB perf.data ]
>>> [root@zoo ~]# perf report | grep -v ^# | head -5
>>> Warning:
>>> 79074 instruction trace errors
>>> 2.80% usleep [unknown] [.] 0x00007f48888aa061
>>> [root@zoo ~]#
>>
>> Running out of ideas. Can you somehow share or send me the offending perf.data file?
>
> http://vger.kernel.org/~acme/perf/perf.data.intel_bts-4.2.0-rc5+.xz
Says: You don't have permission to access
/~acme/perf/perf.data.intel_bts-4.2.0-rc5+.xz on this server.
>
> It works if I use a tip/master kernel:
>
> [root@perf4 ~]# uname -r
> 4.2.0-rc7+
> [root@perf4 ~]# uname -r
> 4.2.0-rc7+
> [root@perf4 ~]# perf record --per-thread -e intel_bts// usleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.785 MB perf.data ]
> [root@perf4 ~]# dmesg | grep Performance
> [ 0.188477] Performance Events: PEBS fmt2+, 16-deep LBR, Broadwell
> events, full-width counters, Intel PMU driver.
> [root@perf4 ~]# perf report --stdio | grep -v ^# | head -10
>
>
>
>
> 10.81% usleep libc-2.17.so [.] _dl_addr
> 6.56% usleep [kernel.kallsyms] [.] unmap_single_vma
> 3.33% usleep ld-2.17.so [.] strcmp
> 2.53% usleep [kernel.kallsyms] [.] mem_cgroup_begin_page_stat
> 2.49% usleep ld-2.17.so [.] _dl_lookup_symbol_x
> 2.39% usleep ld-2.17.so [.] _dl_relocate_object
> [root@perf4 ~]#
>
> Probably some fix for the kernel driver is missing?
Works for me though.
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