Re: [PATCH] rfc: threaded epoll_wait thundering herd

From: Davi Arnaut
Date: Mon May 07 2007 - 19:16:06 EST


Ulrich Drepper wrote:
> On 5/7/07, Davi Arnaut <davi@xxxxxxxxxxxxx> wrote:
>> See Linus's message on this same thread.
>
> No. I'm talking about the userlevel side, not kernel side.

So you probably knew the answer before asking the question.

> If a thread is canceled *after* it returns from the syscall but before
> it reports the event to the call (i.e., while still in the syscall
> wrapper, thread cancellation rules require a check there) the event is
> lost.

Exactly. The same happens with sigwaitinfo(), and various other.

> Linus was only talking about the kernel side and how in the exit path
> such events are not lost.

Anyway, we could extend epoll to be mmapable...

--
Davi Arnaut
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