Messages in this thread |  | | Date | Mon, 30 Jan 2012 12:45:37 -0500 (EST) | Subject | Re: [PATCH] af_unix: fix EPOLLET regression for stream sockets | From | David Miller <> |
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From: Eric Dumazet <eric.dumazet@gmail.com> Date: Sun, 29 Jan 2012 03:11:03 +0100
> Commit 0884d7aa24 (AF_UNIX: Fix poll blocking problem when reading from > a stream socket) added a regression for epoll() in Edge Triggered mode > (EPOLLET) > > Appropriate fix is to use skb_peek()/skb_unlink() instead of > skb_dequeue(), and only call skb_unlink() when skb is fully consumed. > > This remove the need to requeue a partial skb into sk_receive_queue head > and the extra sk->sk_data_ready() calls that added the regression. > > This is safe because once skb is given to sk_receive_queue, it is not > modified by a writer, and readers are serialized by u->readlock mutex. > > This also reduce number of spinlock acquisition for small reads or > MSG_PEEK users so should improve overall performance. > > Reported-by: Nick Mathewson <nickm@freehaven.net> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > Cc: Alexey Moiseytsev <himeraster@gmail.com>
Applied and queued up for -stable, thanks.
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