From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ADAB016FF3B; Fri, 27 Sep 2024 19:05:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727463954; cv=none; b=EYxqjczfkzDRqyofsEBxM9IZoq+OMwBhr0rK1TjZOq7yimtCAYnoyw1qEKUjXJ6q8aRYulEjFIUcihTVf8AO5MREne9pwVUx3RRK30g91vtodcjvjzyqYfiUbS95tm6rV2wb2fJ+ry8nm4pjogDi0NzGd5wHxyHvapJFgG9Bz8I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727463954; c=relaxed/simple; bh=AlVmqydRc0H9M6uSiES4idlufya26gQJmhUiInsVoMM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aCh17W80B7Nu4ehGbjwonEycmtpsHXv04Kts+a8A5vHCLB/VAFJBmxhZUgpkbsSxQsZ32IWlIKf8gwl1CPxdJBbD4Mr4k0bqFLOIbwgGppPlCcXaRUIDn80GjtcXPfTe0anrkiBH9bu/eJEzRGm6B5R2YPGv+QU0o9ibUco9ldQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VQPlB/T7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VQPlB/T7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86E1CC4CEC4; Fri, 27 Sep 2024 19:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727463954; bh=AlVmqydRc0H9M6uSiES4idlufya26gQJmhUiInsVoMM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VQPlB/T7qzO8uuxc1elhRj4hg/sUzm8ppcz/jKj7zzv1LjM68viaJZoYK9bFRU3JN kusPDdDssMCcRYjgPKF+meCQETY6Uj2YopNl1j0V31TdQBF/sFt1oZIDzNbw7gUxRP +t6kggF30jZfjgk/PyHt4+pm8aoP6dYTW/uM6ATypzoxcAGTaPnHjK1dM2KceNZdbI XQL3weL3C54wTigW471cG9thwQ47Su2sKHZJq22J1M7zsg2bXwRDAkk3pQ2Xh7AuIU mFIbqCkH1Nnr0o9kfgot8Qs2fv2cZlh9IdUtNfiL23LPKV2BSF1XAMH0DxYYyZREwB PVVNeGCHTFeEg== Date: Fri, 27 Sep 2024 16:05:50 -0300 From: Arnaldo Carvalho de Melo To: Howard Chu Cc: peterz@infradead.org, mingo@redhat.com, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 0/8] perf record --off-cpu: Dump off-cpu samples directly Message-ID: References: <20240927185340.658143-1-howardchu95@gmail.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240927185340.658143-1-howardchu95@gmail.com> On Fri, Sep 27, 2024 at 11:53:32AM -0700, Howard Chu wrote: > Changes in v5: > - Delete unnecessary copy in BPF program > - Remove sample_embed from perf header, hard code off-cpu stuff instead > - Move evsel__is_offcpu_event() to evsel.h > - Minor changes to the test > - Edit some comments Thanks, I'll try to review and test this early next week, and check on bisectability issues as you mentioned privately. Thanks! - Arnaldo > Changes in v4: > - Minimize the size of data output by perf_event_output() > - Keep only one off-cpu event > - Change off-cpu threshold's unit to microseconds > - Set a default off-cpu threshold > - Print the correct error message for the field 'embed' in perf data header > > Changes in v3: > - Add off-cpu-thresh argument > - Process direct off-cpu samples in post > > Changes in v2: > - Remove unnecessary comments. > - Rename function off_cpu_change_type to off_cpu_prepare_parse > > v1: > > As mentioned in: https://bugzilla.kernel.org/show_bug.cgi?id=207323 > > Currently, off-cpu samples are dumped when perf record is exiting. This > results in off-cpu samples being after the regular samples. This patch > series makes possible dumping off-cpu samples on-the-fly, directly into > perf ring buffer. And it dispatches those samples to the correct format > for perf.data consumers. > > Before: > ``` > migration/0 21 [000] 27981.041319: 2944637851 cycles:P: ffffffff90d2e8aa record_times+0xa ([kernel.kallsyms]) > perf 770116 [001] 27981.041375: 1 cycles:P: ffffffff90ee4960 event_function+0xf0 ([kernel.kallsyms]) > perf 770116 [001] 27981.041377: 1 cycles:P: ffffffff90c184b1 intel_bts_enable_local+0x31 ([kernel.kallsyms]) > perf 770116 [001] 27981.041379: 51611 cycles:P: ffffffff91a160b0 native_sched_clock+0x30 ([kernel.kallsyms]) > migration/1 26 [001] 27981.041400: 4227682775 cycles:P: ffffffff90d06a74 wakeup_preempt+0x44 ([kernel.kallsyms]) > migration/2 32 [002] 27981.041477: 4159401534 cycles:P: ffffffff90d11993 update_load_avg+0x63 ([kernel.kallsyms]) > > sshd 708098 [000] 18446744069.414584: 286392 offcpu-time: > 79a864f1c8bb ppoll+0x4b (/usr/lib/libc.so.6) > 585690935cca [unknown] (/usr/bin/sshd) > ``` > > After: > ``` > perf 774767 [003] 28178.033444: 497 cycles:P: ffffffff91a160c3 native_sched_clock+0x43 ([kernel.kallsyms]) > perf 774767 [003] 28178.033445: 399440 cycles:P: ffffffff91c01f8d nmi_restore+0x25 ([kernel.kallsyms]) > swapper 0 [001] 28178.036639: 376650973 cycles:P: ffffffff91a1ae99 intel_idle+0x59 ([kernel.kallsyms]) > swapper 0 [003] 28178.182921: 348779378 cycles:P: ffffffff91a1ae99 intel_idle+0x59 ([kernel.kallsyms]) > blueman-tray 1355 [000] 28178.627906: 100184571 offcpu-time: > 7528eef1c39d __poll+0x4d (/usr/lib/libc.so.6) > 7528edf7d8fd [unknown] (/usr/lib/libglib-2.0.so.0.8000.2) > 7528edf1af95 g_main_context_iteration+0x35 (/usr/lib/libglib-2.0.so.0.8000.2) > 7528eda4ab86 g_application_run+0x1f6 (/usr/lib/libgio-2.0.so.0.8000.2) > 7528ee6aa596 [unknown] (/usr/lib/libffi.so.8.1.4) > 7fff24e862d8 [unknown] ([unknown]) > > > blueman-tray 1355 [000] 28178.728137: 100187539 offcpu-time: > 7528eef1c39d __poll+0x4d (/usr/lib/libc.so.6) > 7528edf7d8fd [unknown] (/usr/lib/libglib-2.0.so.0.8000.2) > 7528edf1af95 g_main_context_iteration+0x35 (/usr/lib/libglib-2.0.so.0.8000.2) > 7528eda4ab86 g_application_run+0x1f6 (/usr/lib/libgio-2.0.so.0.8000.2) > 7528ee6aa596 [unknown] (/usr/lib/libffi.so.8.1.4) > 7fff24e862d8 [unknown] ([unknown]) > > > swapper 0 [000] 28178.463253: 195945410 cycles:P: ffffffff91a1ae99 intel_idle+0x59 ([kernel.kallsyms]) > dbus-broker 412 [002] 28178.464855: 376737008 cycles:P: ffffffff91c000a0 entry_SYSCALL_64+0x20 ([kernel.kallsyms]) > ``` > > Howard Chu (8): > perf evsel: Set off-cpu BPF output to system-wide > perf record --off-cpu: Add --off-cpu-thresh > perf record --off-cpu: Parse offcpu-time event > perf record off-cpu: Dump direct off-cpu samples in BPF > perf record --off-cpu: Dump total off-cpu time at the end. > perf evsel: Delete unnecessary = 0 > perf record --off-cpu: Parse BPF output embedded data > perf test: Add direct off-cpu dumping test > > tools/perf/builtin-record.c | 26 ++++ > tools/perf/builtin-script.c | 4 +- > tools/perf/tests/builtin-test.c | 1 + > tools/perf/tests/shell/record_offcpu.sh | 29 ++++ > tools/perf/tests/tests.h | 1 + > tools/perf/tests/workloads/Build | 1 + > tools/perf/tests/workloads/offcpu.c | 16 +++ > tools/perf/util/bpf_off_cpu.c | 174 +++++++++++++++--------- > tools/perf/util/bpf_skel/off_cpu.bpf.c | 123 +++++++++++++++++ > tools/perf/util/evsel.c | 47 ++++--- > tools/perf/util/evsel.h | 6 + > tools/perf/util/off_cpu.h | 10 +- > tools/perf/util/record.h | 1 + > tools/perf/util/session.c | 12 +- > 14 files changed, 359 insertions(+), 92 deletions(-) > create mode 100644 tools/perf/tests/workloads/offcpu.c > > -- > 2.43.0