From: David Miller <davem@davemloft.net>
To: herbert@gondor.apana.org.au
Cc: netdev@vger.kernel.org
Subject: Re: tun: Only wake up writers
Date: Wed, 03 Jun 2009 21:46:10 -0700 (PDT) [thread overview]
Message-ID: <20090603.214610.86822955.davem@davemloft.net> (raw)
In-Reply-To: <20090603123655.GA13916@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 3 Jun 2009 22:36:55 +1000
> tun: Only wake up writers
>
> When I added socket accounting to tun I inadvertently introduced
> spurious wake-up events that kills qemu performance. The problem
> occurs when qemu polls on the tun fd for read, and then transmits
> packets. For each packet transmitted, we will wake up qemu even
> if it only cares about read events.
>
> Now this affects all sockets, but it is only a new problem for
> tun. So this patch tries to fix it for tun first and we can then
> look at the problem in general.
>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Applied to net-next-2.6, thanks Herbert!
prev parent reply other threads:[~2009-06-04 4:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-03 3:33 tun: Only wake up writers Herbert Xu
2009-06-03 12:36 ` Herbert Xu
2009-06-04 4:46 ` David Miller [this message]
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