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From: Andy Lutomirski <luto@MIT.EDU>
To: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Jason Baron <jbaron@redhat.com>,
	richard -rw- weinberger <richard.weinberger@gmail.com>,
	torvalds@linux-foundation.org,
	LKML <linux-kernel@vger.kernel.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Lucas De Marchi <lucas.demarchi@profusion.mobi>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH Resend] epoll: add EPOLLEXCLUSIVE support
Date: Thu, 05 Apr 2012 15:30:59 -0700	[thread overview]
Message-ID: <4F7E1D23.1080507@mit.edu> (raw)
In-Reply-To: <20120329150541.GB3173@hell>

On 03/29/2012 08:05 AM, Hagen Paul Pfeifer wrote:
> * Jason Baron | 2012-03-29 10:16:53 [-0400]:
> 
>> Right, for level triggered events, they all wait up. However, if you use
>> edge triggered, ie add 'EPOLLET', then the event gets 'consumed' by the
>> first thread that wakes up, and the subseqent waiters wouldn't get woken
>> up. IE you'll get one wakeup.
> 
> I addressed level triggered, right - it match the model. But I don't wanted to
> wake up every every thread anyway. I don't want to abandon level triggered
> functioning.

I think that what you want is a mode in which, once epoll_wait returns,
the bits it returns get cleared from the event mask.  Am I right?

(To get this right, you'd need another flag that disables the automatic
addition of POLLERR and POLLHUP.)

If you do that and add an extra syscall that simultaneously does a bunch
of epoll_ctls, a timerfd_settime, and an epoll_wait, I'll be extra happy.

--Andy

  parent reply	other threads:[~2012-04-05 22:36 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-28 13:57 [PATCH Resend] epoll: add EPOLLEXCLUSIVE support Hagen Paul Pfeifer
2012-03-28 14:09 ` richard -rw- weinberger
2012-03-28 16:21   ` Jason Baron
2012-03-28 19:58     ` Hagen Paul Pfeifer
2012-03-29 14:16       ` Jason Baron
2012-03-29 15:05         ` Hagen Paul Pfeifer
2012-03-29 15:53           ` Jason Baron
2012-03-29 16:32             ` Hagen Paul Pfeifer
2012-03-29 18:54               ` Jason Baron
2012-03-29 21:19                 ` Hagen Paul Pfeifer
2012-04-05 22:30           ` Andy Lutomirski [this message]
2012-03-29 14:51       ` Hagen Paul Pfeifer

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