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Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee"

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From Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups linux.kernel
Subject Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee"
Date Tue, 08 Sep 2015 19:50:01 +0200
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On Tue, Sep 8, 2015 at 10:39 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> The other patches I do like - why add those list operations that are
> just guaranteed to mess up the cache to add the file descriptors to
> the workqueue list, when we can just do the operation directly?

Side note, it's not just messing with the cache unnecessarily when the
lists grow long, the "cmpxchg" involved in adding the work is fairly
expensive. It may be an unlocked operation, but it's generally as
expensive as a locked one - just without the possibility of a
deadlock.

               Linus
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Thread

[PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Oleg Nesterov <oleg@redhat.com> - 2015-09-08 19:20 +0200
  Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-08 19:40 +0200
    Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-08 19:50 +0200
    Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Oleg Nesterov <oleg@redhat.com> - 2015-09-09 15:20 +0200
      Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-09 18:20 +0200
        Re: [PATCH 3/3] Revert "task_work: remove fifo ordering guarantee" Oleg Nesterov <oleg@redhat.com> - 2015-09-09 18:50 +0200

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