From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Namhyung Kim <namhyung@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Oliver Upton <oliver.upton@linux.dev>,
Yang Jihong <yangjihong1@huawei.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
bpf@vger.kernel.org
Subject: Re: [PATCH v1 2/6] perf trace: Ignore thread hashing in summary
Date: Fri, 16 Feb 2024 11:57:32 -0300 [thread overview]
Message-ID: <Zc933IYjWlkMo4D2@x1> (raw)
In-Reply-To: <CAP-5=fWweUBP_-SHfoADswizMER6axNw89JyG7Fo_qiC883fNw@mail.gmail.com>
On Wed, Feb 14, 2024 at 01:36:46PM -0800, Ian Rogers wrote:
> On Wed, Feb 14, 2024 at 1:15 PM Ian Rogers <irogers@google.com> wrote:
> > On Wed, Feb 14, 2024 at 10:27 AM Ian Rogers <irogers@google.com> wrote:
> > > On Wed, Feb 14, 2024 at 9:25 AM Arnaldo Carvalho de Melo
> > > <acme@kernel.org> wrote:
> > > > On Tue, Feb 13, 2024 at 10:37:04PM -0800, Ian Rogers wrote:
> > > > > Commit 91e467bc568f ("perf machine: Use hashtable for machine
> > > > > threads") made the iteration of thread tids unordered. The perf trace
> > > > > --summary output sorts and prints each hash bucket, rather than all
> > > > > threads globally. Change this behavior by turn all threads into a
> > > > > list, sort the list by number of trace events then by tids, finally
> > > > > print the list. This also allows the rbtree in threads to be not
> > > > > accessed outside of machine.
> > > > Can you please provide a refresh of the output that is changed by your patch?
> > >
> > > Hmm.. looks like perf trace record has broken and doesn't produce
> > > output in newer perfs. It works on 6.5 and so a bisect is necessary.
> >
> > Bisect result:
> > ```
> > 9925495d96efc14d885ba66c5696f664fe0e663c is the first bad commit
> > commit 9925495d96efc14d885ba66c5696f664fe0e663c
> > Author: Ian Rogers <irogers@google.com>
> > Date: Thu Sep 14 14:19:45 2023 -0700
> >
> > perf build: Default BUILD_BPF_SKEL, warn/disable for missing deps
> > ...
> > https://lore.kernel.org/r/20230914211948.814999-3-irogers@google.com
> > ```
> >
> > Now to do the bisect with BUILD_BPF_SKEL=1 on each make.
>
> This looks better (how could I be at fault :-) ):
> ```
> 1836480429d173c01664a633b61e525b13d41a2a is the first bad commit
> commit 1836480429d173c01664a633b61e525b13d41a2a
> Author: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date: Wed Aug 16 13:53:26 2023 -0300
>
> perf bpf_skel augmented_raw_syscalls: Cap the socklen parameter
> using &= sizeof(saddr)
> ...
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ```
> No LKML link.
So simple... ;-\
I've reproduced your steps and got to the same cset while testing on a
recent distro kernel (6.6.13-200.fc39.x86_64), scratching my head now
and trying to figure this out.
Wonder if trying to run on an older kernel the problem would appear.
Will try and add a perf test shell entry with a simple:
root@number:~# perf trace record sleep 0.001 && perf script | head | wc -l
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.034 MB perf.data ]
0
root@number:~#
Has to be 10 :-)
Thanks,
- Arnaldo
next prev parent reply other threads:[~2024-02-16 14:57 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-14 6:37 [PATCH v1 0/6] Thread memory improvements and fixes Ian Rogers
2024-02-14 6:37 ` [PATCH v1 1/6] perf report: Sort child tasks by tid Ian Rogers
2024-02-14 17:24 ` Arnaldo Carvalho de Melo
2024-02-14 17:42 ` Ian Rogers
2024-02-16 20:25 ` Namhyung Kim
2024-02-27 6:39 ` Namhyung Kim
2024-02-27 7:12 ` Ian Rogers
2024-02-28 6:11 ` Namhyung Kim
2024-02-28 7:05 ` Ian Rogers
2024-02-28 22:45 ` Namhyung Kim
2024-02-14 6:37 ` [PATCH v1 2/6] perf trace: Ignore thread hashing in summary Ian Rogers
2024-02-14 17:25 ` Arnaldo Carvalho de Melo
2024-02-14 18:27 ` Ian Rogers
2024-02-14 21:15 ` Ian Rogers
2024-02-14 21:36 ` Ian Rogers
2024-02-14 21:42 ` Ian Rogers
2024-02-16 14:57 ` Arnaldo Carvalho de Melo [this message]
2024-02-27 6:55 ` Namhyung Kim
2024-02-14 6:37 ` [PATCH v1 3/6] perf machine: Move fprintf to for_each loop and a callback Ian Rogers
2024-02-14 6:37 ` [PATCH v1 4/6] perf threads: Move threads to its own files Ian Rogers
2024-02-27 7:07 ` Namhyung Kim
2024-02-27 7:24 ` Ian Rogers
2024-02-27 17:31 ` Namhyung Kim
2024-02-27 19:02 ` Ian Rogers
2024-02-27 19:17 ` Arnaldo Carvalho de Melo
2024-02-27 21:42 ` Ian Rogers
2024-02-28 6:39 ` Namhyung Kim
2024-02-28 7:24 ` Ian Rogers
2024-02-28 23:43 ` Namhyung Kim
2024-02-29 0:31 ` Ian Rogers
2024-02-29 21:59 ` David Laight
2024-03-01 0:19 ` Ian Rogers
2024-02-14 6:37 ` [PATCH v1 5/6] perf threads: Switch from rbtree to hashmap Ian Rogers
2024-02-14 6:37 ` [PATCH v1 6/6] perf threads: Reduce table size from 256 to 8 Ian Rogers
2024-02-25 18:50 ` [PATCH v1 0/6] Thread memory improvements and fixes Ian Rogers
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