[PATCH] sched_setattr.2: callee's affinity matters, not caller's one.

[PATCH] sched_setattr.2: callee's affinity matters, not caller's one.

[Akihiro Suda]

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Hi, all

sched_setattr.2 says:

 EPERM  The caller's CPU affinity mask does not include all CPUs in
the system (see sched_setaffinity(2)).


But it seems that callee's affinity matters, not caller's one.
http://lxr.free-electrons.com/source/kernel/sched/core.c?v=4.3#L3888

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From f2bd53237444dc2c318526c6a9ba0abc447577dc Mon Sep 17 00:00:00 2001
From: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Date: Sat, 2 Jan 2016 21:51:28 +0900
Subject: [PATCH] sched_setattr.2: callee's affinity matters, not caller's one.

http://lxr.free-electrons.com/source/kernel/sched/core.c?v=4.3#L3888
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
---
 man2/sched_setattr.2 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/man2/sched_setattr.2 b/man2/sched_setattr.2
index c411f01..ce6d337 100644
--- a/man2/sched_setattr.2
+++ b/man2/sched_setattr.2
@@ -341,7 +341,7 @@ are invalid.
 The caller does not have appropriate privileges.
 .TP
 .B EPERM
-The caller's CPU affinity mask
+The callee's CPU affinity mask
 does not include all CPUs in the system
 (see
 .BR sched_setaffinity (2)).
-- 
2.5.4 (Apple Git-61)

Re: [PATCH] sched_setattr.2: callee's affinity matters, not caller's one.

[Michael Kerrisk (man-pages)]

Hello Akihiro,

On 01/02/2016 02:04 PM, Akihiro Suda wrote:
> Hi, all
> 
> sched_setattr.2 says:
> 
>  EPERM  The caller's CPU affinity mask does not include all CPUs in
> the system (see sched_setaffinity(2)).
> 
> 
> But it seems that callee's affinity matters, not caller's one.
> http://lxr.free-electrons.com/source/kernel/sched/core.c?v=4.3#L3888

I agree with you. But I think we can word a little more precisely, 
since "callee" isn't so clear. I applied the patch below. Thanks!

Cheers,

Michael

-- a/man2/sched_setattr.2
+++ b/man2/sched_setattr.2
@@ -341,7 +341,8 @@ are invalid.
 The caller does not have appropriate privileges.
 .TP
 .B EPERM
-The caller's CPU affinity mask
+The CPU affinity mask of the thread specified by
+.I pid
 does not include all CPUs in the system
 (see
 .BR sched_setaffinity (2)).


-- 
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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Re: [PATCH] sched_setattr.2: callee's affinity matters, not caller's one.

[Akihiro Suda]

Hello Michael,

OK, and thanks!


2016-01-09 5:27 GMT+09:00 Michael Kerrisk (man-pages) <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> Hello Akihiro,
>
> On 01/02/2016 02:04 PM, Akihiro Suda wrote:
>> Hi, all
>>
>> sched_setattr.2 says:
>>
>>  EPERM  The caller's CPU affinity mask does not include all CPUs in
>> the system (see sched_setaffinity(2)).
>>
>>
>> But it seems that callee's affinity matters, not caller's one.
>> http://lxr.free-electrons.com/source/kernel/sched/core.c?v=4.3#L3888
>
> I agree with you. But I think we can word a little more precisely,
> since "callee" isn't so clear. I applied the patch below. Thanks!
>
> Cheers,
>
> Michael
>
> -- a/man2/sched_setattr.2
> +++ b/man2/sched_setattr.2
> @@ -341,7 +341,8 @@ are invalid.
>  The caller does not have appropriate privileges.
>  .TP
>  .B EPERM
> -The caller's CPU affinity mask
> +The CPU affinity mask of the thread specified by
> +.I pid
>  does not include all CPUs in the system
>  (see
>  .BR sched_setaffinity (2)).
>
>
> --
> 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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