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* perf tools: remove option --tail-synthesize ?
@ 2018-11-21  7:45 Song Liu
  2018-11-21 10:47 ` Jiri Olsa
  2018-11-21 13:11 ` Arnaldo Carvalho de Melo
  0 siblings, 2 replies; 7+ messages in thread
From: Song Liu @ 2018-11-21  7:45 UTC (permalink / raw)
  To: lkml; +Cc: acme, Jiri Olsa, Peter Zijlstra, wangnan0, Kernel Team

Hi,

I found perf-record --tail-synthesize without --overwrite breaks symbols
for perf-script, perf-report, etc. For example:

[root@]# ~/perf record -ag --tail-synthesize -- sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
[root@]# ~/perf script | head
swapper     0 [000] 1250675.051971:          1 cycles:ppp:
        ffffffff81009e15 [unknown] ([unknown])
        ffffffff81196b19 [unknown] ([unknown])
        ffffffff81196579 [unknown] ([unknown])
        ffffffff81110ca7 [unknown] ([unknown])
        ffffffff81a01f4a [unknown] ([unknown])
        ffffffff81a017bf [unknown] ([unknown])
        ffffffff8180e17a [unknown] ([unknown])

perf-record with --overwrite does NOT have this issue.

After digging into this, I found this issue is introduced by commit
a73e24d240bc136619d382b1268f34d75c9d25ce.

Reverting this commit does fix this issue. However, on a second thought,
I feel it is probably better just drop --tail-synthesize, as it doesn't
make much sense without --overwrite. All we need is to do tail_synthesize
when --overwrite is set.

Thoughts?

Thanks,
Song

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-21  7:45 perf tools: remove option --tail-synthesize ? Song Liu
@ 2018-11-21 10:47 ` Jiri Olsa
  2018-11-21 17:56   ` Song Liu
  2018-11-21 13:11 ` Arnaldo Carvalho de Melo
  1 sibling, 1 reply; 7+ messages in thread
From: Jiri Olsa @ 2018-11-21 10:47 UTC (permalink / raw)
  To: Song Liu; +Cc: lkml, acme, Jiri Olsa, Peter Zijlstra, wangnan0, Kernel Team

On Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu wrote:
> Hi,
> 
> I found perf-record --tail-synthesize without --overwrite breaks symbols
> for perf-script, perf-report, etc. For example:
> 
> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
> [root@]# ~/perf script | head
> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
>         ffffffff81009e15 [unknown] ([unknown])
>         ffffffff81196b19 [unknown] ([unknown])
>         ffffffff81196579 [unknown] ([unknown])
>         ffffffff81110ca7 [unknown] ([unknown])
>         ffffffff81a01f4a [unknown] ([unknown])
>         ffffffff81a017bf [unknown] ([unknown])
>         ffffffff8180e17a [unknown] ([unknown])
> 
> perf-record with --overwrite does NOT have this issue.

actualy I think that now it works properly, if you turn on
task and mmap events, you'll see the samples get resolved
right after aux events are processed:

	[root@krava perf]# ./perf script --show-info --show-task-events --show-mmap-events
	...
	swapper     0 [007] 620566.187355:      64821 cycles:ppp:
		ffffffffab0b4d7c [unknown] ([unknown])
		ffffffffaba01b1f [unknown] ([unknown])
		ffffffffab75d567 [unknown] ([unknown])
		ffffffffab0e1f56 [unknown] ([unknown])
		ffffffffab0e216f [unknown] ([unknown])
		ffffffffab050dc7 [unknown] ([unknown])
		ffffffffab0000d5 [unknown] ([unknown])

	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffab000000(0x152c8000) @ 0xffffffffab000000]: x [kernel.kallsyms]_text
	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffc02c8000(0x4000) @ 0]: x /lib/modules/4.18.17-200.fc28.x86_64/kernel/drivers/thermal/int340x_thermal/int3403_thermal.ko.xz
	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffc02cd000(0x4000) @ 0]: x /lib/modules/4.18.17-200.fc28.x86_64/kernel/drivers/thermal/intel_pch_thermal.ko.xz
	...
	ext4-rsv-conver     0 [000]     0.000000: PERF_RECORD_COMM: ext4-rsv-conver:989/989
	perf 20063 [005] 620566.187438:    1056712 cycles:ppp:
		ffffffffab1f605d filemap_map_pages+0x9d (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
		ffffffffab23aaa8 __handle_mm_fault+0x1018 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
		ffffffffab23ae7a handle_mm_fault+0xda (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
		ffffffffab06ac90 __do_page_fault+0x240 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
		ffffffffab06af62 do_page_fault+0x32 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
		ffffffffaba010ee page_fault+0x1e (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
	...

if you record with --overwrite and --tail-synthesize the aux events
will go to the top of the perf.data, so all's good

> 
> After digging into this, I found this issue is introduced by commit
> a73e24d240bc136619d382b1268f34d75c9d25ce.

right, we got rid of that, because it will store the 'current/live'
server mmaps for report/script, which is not what you want

> Reverting this commit does fix this issue. However, on a second thought,
> I feel it is probably better just drop --tail-synthesize, as it doesn't
> make much sense without --overwrite. All we need is to do tail_synthesize
> when --overwrite is set.
> 
> Thoughts?

maybe we should make --tail-synthesize non optionable for --overwrite,
and get rid of that option completely.. Wang, any idea?

but definitelly not allow that for non overwrite

thanks,
jirka

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-21  7:45 perf tools: remove option --tail-synthesize ? Song Liu
  2018-11-21 10:47 ` Jiri Olsa
@ 2018-11-21 13:11 ` Arnaldo Carvalho de Melo
  2018-11-22  1:50   ` Wangnan (F)
  1 sibling, 1 reply; 7+ messages in thread
From: Arnaldo Carvalho de Melo @ 2018-11-21 13:11 UTC (permalink / raw)
  To: Wang Nan; +Cc: Song Liu, lkml, Jiri Olsa, Peter Zijlstra, Kernel Team

Em Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu escreveu:
> Hi,
> 
> I found perf-record --tail-synthesize without --overwrite breaks symbols
> for perf-script, perf-report, etc. For example:
> 
> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
> [root@]# ~/perf script | head
> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
>         ffffffff81009e15 [unknown] ([unknown])
>         ffffffff81196b19 [unknown] ([unknown])
>         ffffffff81196579 [unknown] ([unknown])
>         ffffffff81110ca7 [unknown] ([unknown])
>         ffffffff81a01f4a [unknown] ([unknown])
>         ffffffff81a017bf [unknown] ([unknown])
>         ffffffff8180e17a [unknown] ([unknown])
> 
> perf-record with --overwrite does NOT have this issue.
> 
> After digging into this, I found this issue is introduced by commit
> a73e24d240bc136619d382b1268f34d75c9d25ce.
> 
> Reverting this commit does fix this issue. However, on a second thought,
> I feel it is probably better just drop --tail-synthesize, as it doesn't
> make much sense without --overwrite. All we need is to do tail_synthesize
> when --overwrite is set.
> 
> Thoughts?

Wang, wdyt?

- Arnaldo

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-21 10:47 ` Jiri Olsa
@ 2018-11-21 17:56   ` Song Liu
  0 siblings, 0 replies; 7+ messages in thread
From: Song Liu @ 2018-11-21 17:56 UTC (permalink / raw)
  To: Jiri Olsa; +Cc: lkml, acme, Jiri Olsa, Peter Zijlstra, wangnan0, Kernel Team



> On Nov 21, 2018, at 2:47 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu wrote:
>> Hi,
>> 
>> I found perf-record --tail-synthesize without --overwrite breaks symbols
>> for perf-script, perf-report, etc. For example:
>> 
>> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
>> [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
>> [root@]# ~/perf script | head
>> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
>>        ffffffff81009e15 [unknown] ([unknown])
>>        ffffffff81196b19 [unknown] ([unknown])
>>        ffffffff81196579 [unknown] ([unknown])
>>        ffffffff81110ca7 [unknown] ([unknown])
>>        ffffffff81a01f4a [unknown] ([unknown])
>>        ffffffff81a017bf [unknown] ([unknown])
>>        ffffffff8180e17a [unknown] ([unknown])
>> 
>> perf-record with --overwrite does NOT have this issue.
> 
> actualy I think that now it works properly, if you turn on
> task and mmap events, you'll see the samples get resolved
> right after aux events are processed:
> 
> 	[root@krava perf]# ./perf script --show-info --show-task-events --show-mmap-events
> 	...
> 	swapper     0 [007] 620566.187355:      64821 cycles:ppp:
> 		ffffffffab0b4d7c [unknown] ([unknown])
> 		ffffffffaba01b1f [unknown] ([unknown])
> 		ffffffffab75d567 [unknown] ([unknown])
> 		ffffffffab0e1f56 [unknown] ([unknown])
> 		ffffffffab0e216f [unknown] ([unknown])
> 		ffffffffab050dc7 [unknown] ([unknown])
> 		ffffffffab0000d5 [unknown] ([unknown])
> 
> 	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffab000000(0x152c8000) @ 0xffffffffab000000]: x [kernel.kallsyms]_text
> 	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffc02c8000(0x4000) @ 0]: x /lib/modules/4.18.17-200.fc28.x86_64/kernel/drivers/thermal/int340x_thermal/int3403_thermal.ko.xz
> 	swapper     0 [000]     0.000000: PERF_RECORD_MMAP -1/0: [0xffffffffc02cd000(0x4000) @ 0]: x /lib/modules/4.18.17-200.fc28.x86_64/kernel/drivers/thermal/intel_pch_thermal.ko.xz
> 	...
> 	ext4-rsv-conver     0 [000]     0.000000: PERF_RECORD_COMM: ext4-rsv-conver:989/989
> 	perf 20063 [005] 620566.187438:    1056712 cycles:ppp:
> 		ffffffffab1f605d filemap_map_pages+0x9d (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 		ffffffffab23aaa8 __handle_mm_fault+0x1018 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 		ffffffffab23ae7a handle_mm_fault+0xda (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 		ffffffffab06ac90 __do_page_fault+0x240 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 		ffffffffab06af62 do_page_fault+0x32 (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 		ffffffffaba010ee page_fault+0x1e (/usr/lib/debug/lib/modules/4.18.17-200.fc28.x86_64/vmlinux)
> 	...
> 
> if you record with --overwrite and --tail-synthesize the aux events
> will go to the top of the perf.data, so all's good
> 
>> 
>> After digging into this, I found this issue is introduced by commit
>> a73e24d240bc136619d382b1268f34d75c9d25ce.
> 
> right, we got rid of that, because it will store the 'current/live'
> server mmaps for report/script, which is not what you want

Agreed.

>> Reverting this commit does fix this issue. However, on a second thought,
>> I feel it is probably better just drop --tail-synthesize, as it doesn't
>> make much sense without --overwrite. All we need is to do tail_synthesize
>> when --overwrite is set.
>> 
>> Thoughts?
> 
> maybe we should make --tail-synthesize non optionable for --overwrite,
> and get rid of that option completely.. Wang, any idea?
> 
> but definitelly not allow that for non overwrite
> 

--overwrite forces tail-synthesize already:

        if (record.opts.overwrite)
                record.opts.tail_synthesize = true;

So I guess all we need is to remove --tail-synthesize. If we all agree 
with this direction, I can draft patch for it. 

Thanks,
Song



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-21 13:11 ` Arnaldo Carvalho de Melo
@ 2018-11-22  1:50   ` Wangnan (F)
  2018-11-22  9:03     ` Jiri Olsa
  2018-11-22 18:18     ` Song Liu
  0 siblings, 2 replies; 7+ messages in thread
From: Wangnan (F) @ 2018-11-22  1:50 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Song Liu, lkml, Jiri Olsa, Peter Zijlstra, Kernel Team



On 2018/11/21 21:11, Arnaldo Carvalho de Melo wrote:
> Em Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu escreveu:
>> Hi,
>>
>> I found perf-record --tail-synthesize without --overwrite breaks symbols
>> for perf-script, perf-report, etc. For example:
>>
>> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
>> [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
>> [root@]# ~/perf script | head
>> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
>>         ffffffff81009e15 [unknown] ([unknown])
>>         ffffffff81196b19 [unknown] ([unknown])
>>         ffffffff81196579 [unknown] ([unknown])
>>         ffffffff81110ca7 [unknown] ([unknown])
>>         ffffffff81a01f4a [unknown] ([unknown])
>>         ffffffff81a017bf [unknown] ([unknown])
>>         ffffffff8180e17a [unknown] ([unknown])
>>
>> perf-record with --overwrite does NOT have this issue.
>>
>> After digging into this, I found this issue is introduced by commit
>> a73e24d240bc136619d382b1268f34d75c9d25ce.
>>
>> Reverting this commit does fix this issue. However, on a second thought,
>> I feel it is probably better just drop --tail-synthesize, as it doesn't
>> make much sense without --overwrite. All we need is to do tail_synthesize
>> when --overwrite is set.
>>

Some cases we use --overwrite without --tail-synthesize. How about setting
--tail-synthesize when selecting --overwrite by default, throw a warning
when --overwrite is not set and leave a --no-tail-synthesize option?

Thank you.

>> Thoughts?
> 
> Wang, wdyt?
> 
> - Arnaldo
> 


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-22  1:50   ` Wangnan (F)
@ 2018-11-22  9:03     ` Jiri Olsa
  2018-11-22 18:18     ` Song Liu
  1 sibling, 0 replies; 7+ messages in thread
From: Jiri Olsa @ 2018-11-22  9:03 UTC (permalink / raw)
  To: Wangnan (F)
  Cc: Arnaldo Carvalho de Melo, Song Liu, lkml, Jiri Olsa,
	Peter Zijlstra, Kernel Team

On Thu, Nov 22, 2018 at 09:50:15AM +0800, Wangnan (F) wrote:
> 
> 
> On 2018/11/21 21:11, Arnaldo Carvalho de Melo wrote:
> > Em Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu escreveu:
> >> Hi,
> >>
> >> I found perf-record --tail-synthesize without --overwrite breaks symbols
> >> for perf-script, perf-report, etc. For example:
> >>
> >> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
> >> [ perf record: Woken up 1 times to write data ]
> >> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
> >> [root@]# ~/perf script | head
> >> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
> >>         ffffffff81009e15 [unknown] ([unknown])
> >>         ffffffff81196b19 [unknown] ([unknown])
> >>         ffffffff81196579 [unknown] ([unknown])
> >>         ffffffff81110ca7 [unknown] ([unknown])
> >>         ffffffff81a01f4a [unknown] ([unknown])
> >>         ffffffff81a017bf [unknown] ([unknown])
> >>         ffffffff8180e17a [unknown] ([unknown])
> >>
> >> perf-record with --overwrite does NOT have this issue.
> >>
> >> After digging into this, I found this issue is introduced by commit
> >> a73e24d240bc136619d382b1268f34d75c9d25ce.
> >>
> >> Reverting this commit does fix this issue. However, on a second thought,
> >> I feel it is probably better just drop --tail-synthesize, as it doesn't
> >> make much sense without --overwrite. All we need is to do tail_synthesize
> >> when --overwrite is set.
> >>
> 
> Some cases we use --overwrite without --tail-synthesize. How about setting
> --tail-synthesize when selecting --overwrite by default, throw a warning
> when --overwrite is not set and leave a --no-tail-synthesize option?

sounds good to me

thanks,
jirka

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: perf tools: remove option --tail-synthesize ?
  2018-11-22  1:50   ` Wangnan (F)
  2018-11-22  9:03     ` Jiri Olsa
@ 2018-11-22 18:18     ` Song Liu
  1 sibling, 0 replies; 7+ messages in thread
From: Song Liu @ 2018-11-22 18:18 UTC (permalink / raw)
  To: Wangnan (F)
  Cc: Arnaldo Carvalho de Melo, lkml, Jiri Olsa, Peter Zijlstra, Kernel Team



> On Nov 21, 2018, at 5:50 PM, Wangnan (F) <wangnan0@huawei.com> wrote:
> 
> 
> 
> On 2018/11/21 21:11, Arnaldo Carvalho de Melo wrote:
>> Em Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu escreveu:
>>> Hi,
>>> 
>>> I found perf-record --tail-synthesize without --overwrite breaks symbols
>>> for perf-script, perf-report, etc. For example:
>>> 
>>> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1
>>> [ perf record: Woken up 1 times to write data ]
>>> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ]
>>> [root@]# ~/perf script | head
>>> swapper     0 [000] 1250675.051971:          1 cycles:ppp:
>>>        ffffffff81009e15 [unknown] ([unknown])
>>>        ffffffff81196b19 [unknown] ([unknown])
>>>        ffffffff81196579 [unknown] ([unknown])
>>>        ffffffff81110ca7 [unknown] ([unknown])
>>>        ffffffff81a01f4a [unknown] ([unknown])
>>>        ffffffff81a017bf [unknown] ([unknown])
>>>        ffffffff8180e17a [unknown] ([unknown])
>>> 
>>> perf-record with --overwrite does NOT have this issue.
>>> 
>>> After digging into this, I found this issue is introduced by commit
>>> a73e24d240bc136619d382b1268f34d75c9d25ce.
>>> 
>>> Reverting this commit does fix this issue. However, on a second thought,
>>> I feel it is probably better just drop --tail-synthesize, as it doesn't
>>> make much sense without --overwrite. All we need is to do tail_synthesize
>>> when --overwrite is set.
>>> 
> 
> Some cases we use --overwrite without --tail-synthesize. How about setting
> --tail-synthesize when selecting --overwrite by default, throw a warning
> when --overwrite is not set and leave a --no-tail-synthesize option?
> 

--overwrite implies --tail-synthesize. So with --overwrite, it is always
tail-synthesize. Do we really need --overwrite and --no-tail-synthesize? 
If not, we can probably just drop --tail-synthesize (or mark it as 
deprecated)? 

Thanks,
Song

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2018-11-22 18:18 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-11-21  7:45 perf tools: remove option --tail-synthesize ? Song Liu
2018-11-21 10:47 ` Jiri Olsa
2018-11-21 17:56   ` Song Liu
2018-11-21 13:11 ` Arnaldo Carvalho de Melo
2018-11-22  1:50   ` Wangnan (F)
2018-11-22  9:03     ` Jiri Olsa
2018-11-22 18:18     ` Song Liu

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