Re: [PATCH] perf record: Synthesize cgroup events only if needed

2020-11-30 Thread Namhyung Kim 
Hi Arnaldo,

On Sat, Nov 28, 2020 at 2:30 AM Arnaldo Carvalho de Melo
 wrote:
>
> Em Fri, Nov 27, 2020 at 04:45:57PM +0100, Jiri Olsa escreveu:
> > On Fri, Nov 27, 2020 at 02:43:56PM +0900, Namhyung Kim wrote:
> > > It didn't check the tool->cgroup_events bit which is set when
> > > the --all-cgroups option is given.  Without it, samples will not have
> > > cgroup info so no reason to synthesize.
> > >
> > > We can check the PERF_RECORD_CGROUP records after running perf record
> > > *WITHOUT* the --all-cgroups option:
> > >
> > > Before:
> > >   $ perf report -D | grep CGROUP
> > >   0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
> > >   CGROUP events:  1
> > >   CGROUP events:  0
> > >   CGROUP events:  0
> > >
> > > After:
> > >   $ perf report -D | grep CGROUP
> > >   CGROUP events:  0
> > >   CGROUP events:  0
> > >   CGROUP events:  0
> > >
> > > Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
> > > Signed-off-by: Namhyung Kim 
> > > ---
> > >  tools/perf/util/synthetic-events.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/tools/perf/util/synthetic-events.c 
> > > b/tools/perf/util/synthetic-events.c
> > > index 8a23391558cf..d9c624377da7 100644
> > > --- a/tools/perf/util/synthetic-events.c
> > > +++ b/tools/perf/util/synthetic-events.c
> > > @@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool 
> > > *tool,
> > > char cgrp_root[PATH_MAX];
> > > size_t mount_len;  /* length of mount point in the path */
> > >
> > > +   if (!tool || !tool->cgroup_events)
> > > +   return 0;
> >
> > can !tool actually happen here? or it's just being extra cautious
> >
> > Acked-by: Jiri Olsa 
>
> Thanks, tested with/without --all-cgroups and applied.

Thanks for doing that!

Namhyung

Re: [PATCH] perf record: Synthesize cgroup events only if needed

2020-11-30 Thread Namhyung Kim 
Hi Jiri,

On Sat, Nov 28, 2020 at 12:46 AM Jiri Olsa  wrote:
>
> On Fri, Nov 27, 2020 at 02:43:56PM +0900, Namhyung Kim wrote:
> > It didn't check the tool->cgroup_events bit which is set when
> > the --all-cgroups option is given.  Without it, samples will not have
> > cgroup info so no reason to synthesize.
> >
> > We can check the PERF_RECORD_CGROUP records after running perf record
> > *WITHOUT* the --all-cgroups option:
> >
> > Before:
> >   $ perf report -D | grep CGROUP
> >   0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
> >   CGROUP events:  1
> >   CGROUP events:  0
> >   CGROUP events:  0
> >
> > After:
> >   $ perf report -D | grep CGROUP
> >   CGROUP events:  0
> >   CGROUP events:  0
> >   CGROUP events:  0
> >
> > Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
> > Signed-off-by: Namhyung Kim 
> > ---
> >  tools/perf/util/synthetic-events.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/tools/perf/util/synthetic-events.c 
> > b/tools/perf/util/synthetic-events.c
> > index 8a23391558cf..d9c624377da7 100644
> > --- a/tools/perf/util/synthetic-events.c
> > +++ b/tools/perf/util/synthetic-events.c
> > @@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool 
> > *tool,
> >   char cgrp_root[PATH_MAX];
> >   size_t mount_len;  /* length of mount point in the path */
> >
> > + if (!tool || !tool->cgroup_events)
> > + return 0;
>
> can !tool actually happen here? or it's just being extra cautious

Actually I just copied the namespace code. :).
It's only called from perf record and top, and neither of them pass NULL.

>
> Acked-by: Jiri Olsa 

Thanks,
Namhyung

Re: [PATCH] perf record: Synthesize cgroup events only if needed

2020-11-27 Thread Arnaldo Carvalho de Melo 
Em Fri, Nov 27, 2020 at 04:45:57PM +0100, Jiri Olsa escreveu:
> On Fri, Nov 27, 2020 at 02:43:56PM +0900, Namhyung Kim wrote:
> > It didn't check the tool->cgroup_events bit which is set when
> > the --all-cgroups option is given.  Without it, samples will not have
> > cgroup info so no reason to synthesize.
> > 
> > We can check the PERF_RECORD_CGROUP records after running perf record
> > *WITHOUT* the --all-cgroups option:
> > 
> > Before:
> >   $ perf report -D | grep CGROUP
> >   0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
> >   CGROUP events:  1
> >   CGROUP events:  0
> >   CGROUP events:  0
> > 
> > After:
> >   $ perf report -D | grep CGROUP
> >   CGROUP events:  0
> >   CGROUP events:  0
> >   CGROUP events:  0
> > 
> > Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
> > Signed-off-by: Namhyung Kim 
> > ---
> >  tools/perf/util/synthetic-events.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/tools/perf/util/synthetic-events.c 
> > b/tools/perf/util/synthetic-events.c
> > index 8a23391558cf..d9c624377da7 100644
> > --- a/tools/perf/util/synthetic-events.c
> > +++ b/tools/perf/util/synthetic-events.c
> > @@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool 
> > *tool,
> > char cgrp_root[PATH_MAX];
> > size_t mount_len;  /* length of mount point in the path */
> >  
> > +   if (!tool || !tool->cgroup_events)
> > +   return 0;
> 
> can !tool actually happen here? or it's just being extra cautious
> 
> Acked-by: Jiri Olsa 

Thanks, tested with/without --all-cgroups and applied.

- Arnaldo

Re: [PATCH] perf record: Synthesize cgroup events only if needed

2020-11-27 Thread Jiri Olsa 
On Fri, Nov 27, 2020 at 02:43:56PM +0900, Namhyung Kim wrote:
> It didn't check the tool->cgroup_events bit which is set when
> the --all-cgroups option is given.  Without it, samples will not have
> cgroup info so no reason to synthesize.
> 
> We can check the PERF_RECORD_CGROUP records after running perf record
> *WITHOUT* the --all-cgroups option:
> 
> Before:
>   $ perf report -D | grep CGROUP
>   0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
>   CGROUP events:  1
>   CGROUP events:  0
>   CGROUP events:  0
> 
> After:
>   $ perf report -D | grep CGROUP
>   CGROUP events:  0
>   CGROUP events:  0
>   CGROUP events:  0
> 
> Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
> Signed-off-by: Namhyung Kim 
> ---
>  tools/perf/util/synthetic-events.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/perf/util/synthetic-events.c 
> b/tools/perf/util/synthetic-events.c
> index 8a23391558cf..d9c624377da7 100644
> --- a/tools/perf/util/synthetic-events.c
> +++ b/tools/perf/util/synthetic-events.c
> @@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool *tool,
>   char cgrp_root[PATH_MAX];
>   size_t mount_len;  /* length of mount point in the path */
>  
> + if (!tool || !tool->cgroup_events)
> + return 0;

can !tool actually happen here? or it's just being extra cautious

Acked-by: Jiri Olsa 

thanks,
jirka

> +
>   if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {
>   pr_debug("cannot find cgroup mount point\n");
>   return -1;
> -- 
> 2.29.2.454.gaff20da3a2-goog
>

[PATCH] perf record: Synthesize cgroup events only if needed

2020-11-26 Thread Namhyung Kim 
It didn't check the tool->cgroup_events bit which is set when
the --all-cgroups option is given.  Without it, samples will not have
cgroup info so no reason to synthesize.

We can check the PERF_RECORD_CGROUP records after running perf record
*WITHOUT* the --all-cgroups option:

Before:
  $ perf report -D | grep CGROUP
  0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
  CGROUP events:  1
  CGROUP events:  0
  CGROUP events:  0

After:
  $ perf report -D | grep CGROUP
  CGROUP events:  0
  CGROUP events:  0
  CGROUP events:  0

Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
Signed-off-by: Namhyung Kim 
---
 tools/perf/util/synthetic-events.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/synthetic-events.c 
b/tools/perf/util/synthetic-events.c
index 8a23391558cf..d9c624377da7 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool *tool,
char cgrp_root[PATH_MAX];
size_t mount_len;  /* length of mount point in the path */
 
+   if (!tool || !tool->cgroup_events)
+   return 0;
+
if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {
pr_debug("cannot find cgroup mount point\n");
return -1;
-- 
2.29.2.454.gaff20da3a2-goog