Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1276559
| From | David Ahern <dsahern@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] perf record: Add snapshot mode support for perf's regular events |
| Date | 2015-11-24 16:10 +0100 |
| Message-ID | <qynoe-1lP-35@gated-at.bofh.it> (permalink) |
| References | <qymiv-n6-27@gated-at.bofh.it> <qymiv-n6-49@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 11/24/15 7:00 AM, Yunlong Song wrote:
> +static int record__write(struct record *rec, void *bf, size_t size)
> +{
> + if (rec->memory.size && memory_enabled) {
> + if (perf_memory__write(&rec->memory, bf, size) < 0) {
> + pr_err("failed to write memory data, error: %m\n");
> + return -1;
> + }
> + } else {
> + if (perf_data_file__write(rec->session->file, bf, size) < 0) {
> + pr_err("failed to write perf data, error: %m\n");
> + return -1;
> + }
> + rec->bytes_written += size;
> }
>
> - rec->bytes_written += size;
> return 0;
> }
>
> @@ -86,6 +214,8 @@ static int record__mmap_read(struct record *rec, int idx)
> if (old == head)
> return 0;
>
> + memory_enabled = 1;
> +
> rec->samples++;
>
> size = head - old;
> @@ -113,6 +243,7 @@ static int record__mmap_read(struct record *rec, int idx)
> md->prev = old;
> perf_evlist__mmap_consume(rec->evlist, idx);
> out:
> + memory_enabled = 0;
> return rc;
> }
>
So you are basically ignoring all samples until SIGUSR2 is received.
That means the resulting data file will have limited history of task
events for example. And for other events the quantity is random as to
when the mmaps were last scanned.
Your cover letter mentioned my code "just makes some count when the
signal triggers perf sched, with no sample recording and has nothing to
do with perf.data". That is not correct. If you look at the perf-daemon
code I pointed you to it processes task events as they are received and
saves the last N-events after time sorting (limited by memory or time).
When a signal is received it processes the saved events and dumps them
to stdout versus writing a perf.data file.
David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH] perf record: Add snapshot mode support for perf's regular events Yunlong Song <yunlong.song@huawei.com> - 2015-11-24 15:00 +0100
[PATCH] perf record: Add snapshot mode support for perf's regular events Yunlong Song <yunlong.song@huawei.com> - 2015-11-24 15:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-11-24 15:40 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Yunlong Song <yunlong.song@huawei.com> - 2015-11-25 13:50 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events David Ahern <dsahern@gmail.com> - 2015-11-24 16:10 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-11-24 16:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events David Ahern <dsahern@gmail.com> - 2015-11-24 16:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> - 2015-11-24 16:50 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events David Ahern <dsahern@gmail.com> - 2015-11-24 17:20 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-25 05:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events David Ahern <dsahern@gmail.com> - 2015-11-25 06:10 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Adrian Hunter <adrian.hunter@intel.com> - 2015-11-25 08:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-25 09:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Adrian Hunter <adrian.hunter@intel.com> - 2015-11-25 09:40 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-25 10:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Adrian Hunter <adrian.hunter@intel.com> - 2015-11-25 10:10 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Yunlong Song <yunlong.song@huawei.com> - 2015-11-25 09:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Peter Zijlstra <peterz@infradead.org> - 2015-11-25 10:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-25 10:50 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Peter Zijlstra <peterz@infradead.org> - 2015-11-25 13:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-25 14:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Ingo Molnar <mingo@kernel.org> - 2015-11-26 10:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Ingo Molnar <mingo@kernel.org> - 2015-11-26 10:50 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Ingo Molnar <mingo@kernel.org> - 2015-11-26 11:00 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-26 10:30 +0100
Re: [PATCH] perf record: Add snapshot mode support for perf's regular events Ingo Molnar <mingo@kernel.org> - 2015-11-26 10:30 +0100
csiph-web