From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH 2/2] af_unix: optimize unix_dgram_poll()
Date: Mon, 08 Nov 2010 13:44:44 -0800 (PST)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 31 Oct 2010 16:38:25 +0100

> unix_dgram_poll() is pretty expensive to check POLLOUT status, because
> it has to lock the socket to get its peer, take a reference on the peer
> to check its receive queue status, and queue another poll_wait on
> peer_wait. This all can be avoided if the process calling
> unix_dgram_poll() is not interested in POLLOUT status. It makes
> unix_dgram_recvmsg() faster by not queueing irrelevant pollers in
> peer_wait.
> 
> On a test program provided by Alan Crequy :
> 
> Before:
> 
> real    0m0.211s
> user    0m0.000s
> sys     0m0.208s
> 
> After:
> 
> real    0m0.044s
> user    0m0.000s
> sys     0m0.040s
> 
> Suggested-by: Davide Libenzi <davidel@xmailserver.org>
> Reported-by: Alban Crequy <alban.crequy@collabora.co.uk>
> Acked-by: Davide Libenzi <davidel@xmailserver.org>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied.