[patch] perf_event_open.2 E2BIG documentation

[patch] perf_event_open.2 E2BIG documentation

[Vince Weaver]

The following documents the E2BIG error return for perf_event_open().

I actually ran into this error the hard way and it took me half a day
to figure out why my ->size value was changing.

Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 71a09d5..f4cb5bd 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -2121,6 +2121,21 @@ returns the new file descriptor, or \-1 if an error occurred
 is set appropriately).
 .SH ERRORS
 .TP
+.B E2BIG
+Returned if the perf_event_attr
+.I size
+value is too small
+(smaller than
+.BR PERF_ATTR_SIZE_VER0 ),
+too big (larger than the page size),
+or larger than the kernel supports and the extra bytes are not zero.
+When
+.B E2BIG
+is returned, the perf_event_attr
+.I size 
+field is over-written by the kernel to be the size of the structure
+it was expecting.
+.TP
 .B EINVAL
 Returned if the specified event is not available.
 .TP
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Re: [patch] perf_event_open.2 E2BIG documentation

[Michael Kerrisk (man-pages)]

On 11.10.2013 10:20, Vince Weaver wrote:
> 
> The following documents the E2BIG error return for perf_event_open().
> 
> I actually ran into this error the hard way and it took me half a day
> to figure out why my ->size value was changing.
> 
> Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>

Thanks, Vince. Applied.

Cheers,

Michael


> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
> index 71a09d5..f4cb5bd 100644
> --- a/man2/perf_event_open.2
> +++ b/man2/perf_event_open.2
> @@ -2121,6 +2121,21 @@ returns the new file descriptor, or \-1 if an error occurred
>  is set appropriately).
>  .SH ERRORS
>  .TP
> +.B E2BIG
> +Returned if the perf_event_attr
> +.I size
> +value is too small
> +(smaller than
> +.BR PERF_ATTR_SIZE_VER0 ),
> +too big (larger than the page size),
> +or larger than the kernel supports and the extra bytes are not zero.
> +When
> +.B E2BIG
> +is returned, the perf_event_attr
> +.I size 
> +field is over-written by the kernel to be the size of the structure
> +it was expecting.
> +.TP
>  .B EINVAL
>  Returned if the specified event is not available.
>  .TP
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
My next Linux/UNIX system programming course:
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