Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1670754 > unrolled thread

Re: [PATCH] perf/core: make sure group events are for the same cpu

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH] perf/core: make sure group events are for the same cpu Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2017-06-20 15:20 +0200
    Re: [PATCH] perf/core: make sure group events are for the same cpu zhouchengming <zhouchengming1@huawei.com> - 2017-06-21 09:00 +0200

#1670754 — Re: [PATCH] perf/core: make sure group events are for the same cpu

Zhou Chengming <zhouchengming1@huawei.com> writes:

> The else branch are broken for taskctx:

This is not a good way to open a commit message.

> two events can on the same taskctx, but on different cpu.

How?

Regards,
--
Alex

[toc] | [next] | [standalone]

#1671406

On 2017/6/20 21:08, Alexander Shishkin wrote:
> Zhou Chengming<zhouchengming1@huawei.com>  writes:
>
>> The else branch are broken for taskctx:
> This is not a good way to open a commit message.
>
>> two events can on the same taskctx, but on different cpu.
> How?

fd1 = perf_open_event(attr, pid, 0, -1, flags);
fd2 = perf_open_event(attr, pid, 1, fd1, flags);

fd1 will be the leader event,  fd2 will be the sibling event in the group.

And they are for the same task, so they will be put on the same taskctx successfully
if !move_group.

Obviously it's wrong, we can't concurrently schedule them as a group, since they are
on different cpu.

Thanks.

>
> Regards,
> --
> Alex
>
> .
>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web