Re: [patch 04/11] perf_event_open.2: 4.1 data_offset and data_size fields

From: Michael Kerrisk (man-pages)
Date: Wed Oct 14 2015 - 02:29:32 EST


On 07/23/2015 07:11 PM, Vince Weaver wrote:
>
> This manpage patch relates to the addition of the data_offset
> and data_size fields to the perf_event mmap buffer, as added
> in the following commit:

Thanks, Vince. Applied.

Cheers,

Michael



> commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
> Author: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
>
> perf: Add data_{offset,size} to user_page
>
> Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: H. Peter Anvin <hpa@xxxxxxxxx>
> Cc: Kaixu Xia <kaixu.xia@xxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Mike Galbraith <efault@xxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Robert Richter <rric@xxxxxxxxxx>
> Cc: Stephane Eranian <eranian@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: acme@xxxxxxxxxxxxx
> Cc: adrian.hunter@xxxxxxxxx
> Cc: kan.liang@xxxxxxxxx
> Cc: markus.t.metzger@xxxxxxxxx
> Cc: mathieu.poirier@xxxxxxxxxx
> Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@xxxxxxxxxxxxxxx
> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
>
>
> Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
>
> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
> index 09eda9a..a3bebaa 100644
> --- a/man2/perf_event_open.2
> +++ b/man2/perf_event_open.2
> @@ -1414,6 +1414,9 @@ struct perf_event_mmap_page {
> __u64 __reserved[120]; /* Pad to 1k */
> __u64 data_head; /* head in the data section */
> __u64 data_tail; /* user-space written tail */
> + __u64 data_offset; /* where the buffer starts */
> + __u64 data_size; /* data buffer size */
> +
> }
> .fi
> .in
> @@ -1630,6 +1633,16 @@ the
> .I data_tail
> value should be written by user space to reflect the last read data.
> In this case, the kernel will not overwrite unread data.
> +.TP
> +.IR data_offset " (since Linux 4.1)"
> +.\" commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
> +Contains the offset of the location in the mmap buffer
> +where perf sample data begins.
> +.TP
> +.IR data_size " (since Linux 4.1)"
> +.\" commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
> +Contains the size of the perf sample region within
> +the mmap buffer.
> .PP
> The following 2^n ring-buffer pages have the layout described below.
>
>


--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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