From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yang Jihong <yangjihong1@huawei.com>,
peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com, jolsa@kernel.org,
namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com,
kan.liang@linux.intel.com, james.clark@arm.com,
tmricht@linux.ibm.com, ak@linux.intel.com,
anshuman.khandual@arm.com, linux-kernel@vger.kernel.org,
linux-perf-users@vger.kernel.org
Subject: Re: [PATCH v8 0/6] perf record: Track sideband events for all CPUs when tracing selected CPUs
Date: Tue, 12 Sep 2023 17:32:34 -0300 [thread overview]
Message-ID: <ZQDK4kZhwyZL/8tx@kernel.org> (raw)
In-Reply-To: <453bd95c-932d-c60a-bd7b-96f87bc7779a@amd.com>
Em Tue, Sep 12, 2023 at 02:41:56PM +0530, Ravi Bangoria escreveu:
> On 04-Sep-23 8:03 AM, Yang Jihong wrote:
> > User space tasks can migrate between CPUs, track sideband events for all
> > CPUs.
> >
> > The specific scenarios are as follows:
> >
> > CPU0 CPU1
> > perf record -C 0 start
> > taskA starts to be created and executed
> > -> PERF_RECORD_COMM and PERF_RECORD_MMAP
> > events only deliver to CPU1
> > ......
> > |
> > migrate to CPU0
> > |
> > Running on CPU0 <----------/
> > ...
> >
> > perf record -C 0 stop
> >
> > Now perf samples the PC of taskA. However, perf does not record the
> > PERF_RECORD_COMM and PERF_RECORD_COMM events of taskA.
> > Therefore, the comm and symbols of taskA cannot be parsed.
> >
> > The sys_perf_event_open invoked is as follows:
> >
> > # perf --debug verbose=3 record -e cpu-clock -C 1 true
> > <SNIP>
> > Opening: cpu-clock
> > ------------------------------------------------------------
> > perf_event_attr:
> > type 1 (PERF_TYPE_SOFTWARE)
> > size 136
> > config 0 (PERF_COUNT_SW_CPU_CLOCK)
> > { sample_period, sample_freq } 4000
> > sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> > read_format ID|LOST
> > disabled 1
> > inherit 1
> > freq 1
> > sample_id_all 1
> > exclude_guest 1
> > ------------------------------------------------------------
> > sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 5
> > Opening: dummy:u
> > ------------------------------------------------------------
> > perf_event_attr:
> > type 1 (PERF_TYPE_SOFTWARE)
> > size 136
> > config 0x9 (PERF_COUNT_SW_DUMMY)
> > { sample_period, sample_freq } 1
> > sample_type IP|TID|TIME|CPU|IDENTIFIER
> > read_format ID|LOST
> > inherit 1
> > exclude_kernel 1
> > exclude_hv 1
> > mmap 1
> > comm 1
> > task 1
> > sample_id_all 1
> > exclude_guest 1
> > mmap2 1
> > comm_exec 1
> > ksymbol 1
> > bpf_event 1
> > ------------------------------------------------------------
> > sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 6
> > sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 7
> > sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 = 9
> > sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 = 10
> > sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 = 11
> > sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 = 12
> > sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 = 13
> > sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 = 14
> > <SNIP>
> >
> > Changes since_v7:
> > - The condition for requiring system_wide sideband is changed to
> > "as long as a non-dummy event exists" (patch4).
> > - Modify the corresponding test case to record only dummy event (patch6).
> > - Thanks to tested-by tag from Ravi, but because the solution is modified,
> > the tested-by tag of Ravi is not added to this version.
>
> I've re-tested v8 with my simple test.
>
> Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Thanks, applied to the csets that were still sitting in an umpublished
perf-tools-next local branch, soon public.
- Arnaldo
next prev parent reply other threads:[~2023-09-12 20:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-04 2:33 [PATCH v8 0/6] perf record: Track sideband events for all CPUs when tracing selected CPUs Yang Jihong
2023-09-04 2:33 ` [PATCH v8 1/6] perf evlist: Add perf_evlist__go_system_wide() helper Yang Jihong
2023-09-04 2:33 ` [PATCH v8 2/6] perf evlist: Add evlist__findnew_tracking_event() helper Yang Jihong
2023-09-04 2:33 ` [PATCH v8 3/6] perf record: Move setting tracking events before record__init_thread_masks() Yang Jihong
2023-09-04 2:33 ` [PATCH v8 4/6] perf record: Track sideband events for all CPUs when tracing selected CPUs Yang Jihong
2023-09-04 2:33 ` [PATCH v8 5/6] perf test: Add test case for record sideband events Yang Jihong
2023-09-04 2:33 ` [PATCH v8 6/6] perf test: Add perf_event_attr test for record dummy event Yang Jihong
2023-09-06 16:08 ` [PATCH v8 0/6] perf record: Track sideband events for all CPUs when tracing selected CPUs Arnaldo Carvalho de Melo
2023-09-07 2:40 ` Yang Jihong
2023-09-12 9:11 ` Ravi Bangoria
2023-09-12 20:32 ` Arnaldo Carvalho de Melo [this message]
2023-09-16 0:14 ` Namhyung Kim
2023-09-16 9:23 ` Yang Jihong
2023-09-17 5:34 ` Namhyung Kim
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