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From: David Ahern <dsahern@gmail.com>
To: Pawel Moll <pawel.moll@arm.com>,
	Richard Cochran <richardcochran@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Paul Mackerras <paulus@samba.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	John Stultz <john.stultz@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [RFC 2/2] perf: Marker software event and ioctl
Date: Fri, 12 Sep 2014 10:37:39 -0700	[thread overview]
Message-ID: <54132F63.1010401@gmail.com> (raw)
In-Reply-To: <1410522513-1045-3-git-send-email-pawel.moll@arm.com>

On 9/12/14, 4:48 AM, Pawel Moll wrote:
> This patch adds a PERF_COUNT_SW_MARKER event type, which
> can be requested by user and a PERF_EVENT_IOC_MARKER
> ioctl command which will inject an event of said type into
> the perf buffer. The ioctl can take a zero-terminated
> string argument, similar to tracing_marker in ftrace,
> which will be kept in the "raw" field of the sample.
>
> The main use case for this is synchronisation of
> performance data generated in user space with the perf
> stream coming from the kernel. For example, the marker
> can be inserted by a JIT engine after it generated
> portion of the code, but before the code is executed
> for the first time, allowing the post-processor to
> pick the correct debugging information. Other example
> is a system profiling tool taking data from other
> sources than just perf, which generates a marker
> at the beginning at at the end of the session
> (also possibly periodically during the session) to
> synchronise kernel timestamps with clock values
> obtained in userspace (gtod or raw_monotonic).

Seems really similar to what I proposed in the past:

https://lkml.org/lkml/2011/2/27/159

Which was rejected.

David

WARNING: multiple messages have this Message-ID (diff)
From: David Ahern <dsahern-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
	Richard Cochran
	<richardcochran-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>,
	Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
	Arnaldo Carvalho de Melo
	<acme-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	John Stultz <john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC 2/2] perf: Marker software event and ioctl
Date: Fri, 12 Sep 2014 10:37:39 -0700	[thread overview]
Message-ID: <54132F63.1010401@gmail.com> (raw)
In-Reply-To: <1410522513-1045-3-git-send-email-pawel.moll-5wv7dgnIgG8@public.gmane.org>

On 9/12/14, 4:48 AM, Pawel Moll wrote:
> This patch adds a PERF_COUNT_SW_MARKER event type, which
> can be requested by user and a PERF_EVENT_IOC_MARKER
> ioctl command which will inject an event of said type into
> the perf buffer. The ioctl can take a zero-terminated
> string argument, similar to tracing_marker in ftrace,
> which will be kept in the "raw" field of the sample.
>
> The main use case for this is synchronisation of
> performance data generated in user space with the perf
> stream coming from the kernel. For example, the marker
> can be inserted by a JIT engine after it generated
> portion of the code, but before the code is executed
> for the first time, allowing the post-processor to
> pick the correct debugging information. Other example
> is a system profiling tool taking data from other
> sources than just perf, which generates a marker
> at the beginning at at the end of the session
> (also possibly periodically during the session) to
> synchronise kernel timestamps with clock values
> obtained in userspace (gtod or raw_monotonic).

Seems really similar to what I proposed in the past:

https://lkml.org/lkml/2011/2/27/159

Which was rejected.

David

  parent reply	other threads:[~2014-09-12 17:37 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-12 11:48 [RFC 0/2] Yet another take at user/kernel time correlation problem Pawel Moll
2014-09-12 11:48 ` [RFC 1/2] perf: Add sampling of the raw monotonic clock Pawel Moll
2014-09-12 11:48 ` [RFC 2/2] perf: Marker software event and ioctl Pawel Moll
2014-09-12 11:48   ` Pawel Moll
2014-09-12 12:43   ` Christopher Covington
2014-09-12 12:43     ` Christopher Covington
2014-09-12 12:57     ` Pawel Moll
2014-09-12 12:57       ` Pawel Moll
2014-09-12 13:49       ` Arnaldo Carvalho de Melo
2014-09-12 13:49         ` Arnaldo Carvalho de Melo
2014-09-12 13:58         ` Pawel Moll
2014-09-12 13:58           ` Pawel Moll
2014-09-12 16:19           ` Arnaldo Carvalho de Melo
2014-09-12 16:19             ` Arnaldo Carvalho de Melo
2014-09-15 17:27             ` Pawel Moll
2014-09-15 17:27               ` Pawel Moll
2014-09-15 18:31               ` Arnaldo Carvalho de Melo
2014-09-15 18:31                 ` Arnaldo Carvalho de Melo
2014-09-16 16:33                 ` Pawel Moll
2014-09-16 16:33                   ` Pawel Moll
2014-09-12 14:00       ` Christopher Covington
2014-09-12 14:00         ` Christopher Covington
2014-09-12 17:37   ` David Ahern [this message]
2014-09-12 17:37     ` David Ahern
2014-09-12 20:44     ` Arnaldo Carvalho de Melo
2014-09-12 20:44       ` Arnaldo Carvalho de Melo
2014-09-14 15:43       ` David Ahern
2014-09-15 17:18         ` Pawel Moll
2014-09-15 17:18           ` Pawel Moll
2014-09-16  7:44         ` Ingo Molnar
2014-09-16  7:44           ` Ingo Molnar
2014-09-16 16:37           ` Pawel Moll
2014-09-16 16:37             ` Pawel Moll
2014-09-16 17:58             ` Ingo Molnar
2014-09-16 17:58               ` Ingo Molnar

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