linux-kernel - Re: [PATCHSET 00/12] perf tools: Apply percent-limit to callchains

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Message-ID: <20160126155417.GC6506@danjae.kornet>
Date:	Wed, 27 Jan 2016 00:54:17 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Jiri Olsa <jolsa@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>,
	David Ahern <dsahern@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Wang Nan <wangnan0@...wei.com>
Subject: Re: [PATCHSET 00/12] perf tools: Apply percent-limit to callchains

On Tue, Jan 26, 2016 at 04:41:16PM +0100, Jiri Olsa wrote:
> On Tue, Jan 26, 2016 at 12:30:36PM -0300, Arnaldo Carvalho de Melo wrote:
> > Em Tue, Jan 26, 2016 at 04:18:00PM +0100, Jiri Olsa escreveu:
> > > On Tue, Jan 26, 2016 at 11:49:07PM +0900, Namhyung Kim wrote:
> > > 
> > > SNIP
> > > 
> > > > >                __hrtimer_run_queues
> > > > >                tick_sched_timer
> > > > >                tick_sched_handle.isra.17
> > > > >                update_process_times
> > > > >                scheduler_tick
> > > > >                perf_event_task_tick
> > > > >                perf_pmu_enable.part.87
> > > > >                x86_pmu_enable
> > > > >                intel_pmu_enable_all
> > > > >                intel_bts_enable_local
> > > > > 
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] perf_pmu_enable.part.87     
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] perf_event_context_sched_in 
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] perf_event_exec             
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] setup_new_exec              
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] load_elf_binary             
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] search_binary_handler       
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] do_execveat_common.isra.33  
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] sys_execve                  
> > > > >      0.08%     0.00%  perf     [kernel.vmlinux]  [k] return_from_execve          
> > > > >      0.08%     0.00%  perf     [unknown]         [k] 0x00007f2175b35e07          
> > > > >      0.04%     0.00%  perf     [kernel.vmlinux]  [k] perf_event_nmi_handler      
> > > > >      0.04%     0.00%  perf     [kernel.vmlinux]  [k] nmi_handle                  
> > > > >      0.04%     0.00%  perf     [kernel.vmlinux]  [k] default_do_nmi              
> > > > >      0.04%     0.00%  perf     [kernel.vmlinux]  [k] do_nmi                      
> > > > >      0.04%     0.00%  perf     [kernel.vmlinux]  [k] end_repeat_nmi              
> > > > >      0.04%     0.04%  perf     [kernel.vmlinux]  [k] x86_pmu_enable              
> > > > >      0.04%     0.04%  perf     [kernel.vmlinux]  [k] native_apic_mem_write       
> > > > > 
> > > > 
> > > > What's the problem?  Now by default callchains under 0.5% (absolute)
> > > > will not be shown.  I think this is intended output, and we need to
> > > > consider changing the default percent limit.
> > > 
> > > hm, just the TUI shows +- for entries with no callchain
> > 
> > Humm, this is an old bug, never got around to try to fix it, or is this
> > something you were not experiencing before this patchkit from Namhyung?
> > 
> 
> well, there were callchains present before this patchset ;-)

That is because we apply percent limit to callchains now, and the
default is 0.5%.  Before this patchset percent limit seems not applied
so you saw the callchains under the limit.

Thanks,
Namhyung