Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-21 Thread Namhyung Kim
Hi Steve, On Sat, Jul 18, 2020 at 4:44 AM Steven Rostedt wrote: > > On Fri, 17 Jul 2020 16:34:55 -0300 > Arnaldo Carvalho de Melo wrote: > > Thinking a bit more, I have to ask. Does perf use the kernel when > getting all the children of an existing task, or is that done only in > userspace? > >

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Changbin Du
On Fri, Jul 17, 2020 at 01:01:24PM -0400, Steven Rostedt wrote: > On Fri, 17 Jul 2020 21:26:50 +0800 > Changbin Du wrote: > > > On Thu, Jul 16, 2020 at 12:36:30PM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > > > > This allows us

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Steven Rostedt
On Fri, 17 Jul 2020 16:34:55 -0300 Arnaldo Carvalho de Melo wrote: Thinking a bit more, I have to ask. Does perf use the kernel when getting all the children of an existing task, or is that done only in userspace? That is, is there a perf syscall that says "start tracing this task and all its

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Arnaldo Carvalho de Melo
Em Fri, Jul 17, 2020 at 01:53:51PM -0400, Steven Rostedt escreveu: > On Fri, 17 Jul 2020 14:40:53 -0300 Arnaldo Carvalho de Melo > wrote: > > Say you use: > > ^C[root@ssdandy ~]# cyclictest --smp -um -p95 > > # /dev/cpu_dma_latency set to 0us > > policy: fifo: loadavg: 0.05 0.03 0.06 2/409

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Steven Rostedt
On Fri, 17 Jul 2020 14:40:53 -0300 Arnaldo Carvalho de Melo wrote: > Say you use: > > ^C[root@ssdandy ~]# cyclictest --smp -um -p95 > # /dev/cpu_dma_latency set to 0us > policy: fifo: loadavg: 0.05 0.03 0.06 2/409 29072 > > T: 0 (29065) P:95 I:1000 C:518 Min: 2 Act:2 Avg:2

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Arnaldo Carvalho de Melo
Em Fri, Jul 17, 2020 at 01:01:24PM -0400, Steven Rostedt escreveu: > On Fri, 17 Jul 2020 21:26:50 +0800 > Changbin Du wrote: > > > On Thu, Jul 16, 2020 at 12:36:30PM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > > > > This allows

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Steven Rostedt
On Fri, 17 Jul 2020 21:26:50 +0800 Changbin Du wrote: > On Thu, Jul 16, 2020 at 12:36:30PM -0300, Arnaldo Carvalho de Melo wrote: > > Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > > > This allows us to trace single thread instead of the whole process. > > > > > >

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Arnaldo Carvalho de Melo
Em Fri, Jul 17, 2020 at 09:26:50PM +0800, Changbin Du escreveu: > On Thu, Jul 16, 2020 at 12:36:30PM -0300, Arnaldo Carvalho de Melo wrote: > > Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > > > +++ b/tools/perf/Documentation/perf-ftrace.txt > > > @@ -38,6 +38,10 @@ OPTIONS > >

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-17 Thread Changbin Du
On Thu, Jul 16, 2020 at 12:36:30PM -0300, Arnaldo Carvalho de Melo wrote: > Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > > This allows us to trace single thread instead of the whole process. > > > > Signed-off-by: Changbin Du > > --- > >

Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

2020-07-16 Thread Arnaldo Carvalho de Melo
Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu: > This allows us to trace single thread instead of the whole process. > > Signed-off-by: Changbin Du > --- > tools/perf/Documentation/perf-ftrace.txt | 4 > tools/perf/builtin-ftrace.c | 2 ++ > 2 files changed, 6