From: Ravi Bangoria <ravi.bangoria@amd.com>
To: Yang Jihong <yangjihong1@huawei.com>, acme@kernel.org
Cc: 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,
Ravi Bangoria <ravi.bangoria@amd.com>
Subject: Re: [PATCH v8 0/6] perf record: Track sideband events for all CPUs when tracing selected CPUs
Date: Tue, 12 Sep 2023 14:41:56 +0530 [thread overview]
Message-ID: <453bd95c-932d-c60a-bd7b-96f87bc7779a@amd.com> (raw)
In-Reply-To: <20230904023340.12707-1-yangjihong1@huawei.com>
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>
next prev parent reply other threads:[~2023-09-12 9:12 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 [this message]
2023-09-12 20:32 ` Arnaldo Carvalho de Melo
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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