From: Andi Kleen <andi@firstfloor.org>
To: Zan Lynx <zlynx@acm.org>
Cc: Andi Kleen <andi@firstfloor.org>, Jiri Olsa <jolsa@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
fbl@redhat.com, nhorman@redhat.com, davem@redhat.com,
oleg@redhat.com, eric.dumazet@gmail.com
Subject: Re: [PATCH] net: fix race in the receive/select
Date: Mon, 29 Jun 2009 19:29:38 +0200 [thread overview]
Message-ID: <20090629172938.GE6760@one.firstfloor.org> (raw)
In-Reply-To: <4A48F30D.8000803@acm.org>
On Mon, Jun 29, 2009 at 10:59:57AM -0600, Zan Lynx wrote:
> Andi Kleen wrote:
> >At least on x86 I can't see how it happens. mb() is only a compile
> >time barrier and the compiler doesn't optimize over indirect callbacks
> >like __pollwait() anyways.
>
> Just a note about this. That used to be true, that GCC didn't optimize
> indirect calls. However, see -findirect-inlining in GCC 4.4.
I am aware of that, but ...
>
> I am not saying that it applies here, but it is something to remember.
... it doesn't apply here because it works only for a few very simple
cases that don't apply for this code. Besides the kernel builds with -O2,
which only inlines functions called once or very small functions, which
also rules this out.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-06-29 17:29 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-25 12:25 [PATCH] net: fix race in the receive/select Jiri Olsa
2009-06-25 12:24 ` Oleg Nesterov
2009-06-26 1:31 ` Davide Libenzi
2009-06-26 1:59 ` Eric Dumazet
2009-06-26 2:04 ` Davide Libenzi
2009-06-26 2:11 ` David Miller
2009-06-26 2:19 ` Eric Dumazet
2009-06-26 3:14 ` Davide Libenzi
2009-06-26 5:42 ` Jarek Poplawski
2009-06-26 8:10 ` Jarek Poplawski
2009-06-26 13:57 ` Oleg Nesterov
2009-06-26 17:32 ` Davide Libenzi
2009-06-26 14:50 ` Oleg Nesterov
2009-06-26 18:12 ` Davide Libenzi
2009-06-26 18:17 ` David Miller
2009-06-26 19:35 ` Eric Dumazet
2009-06-29 9:34 ` Jiri Olsa
2009-06-28 11:10 ` Jarek Poplawski
2009-06-28 11:22 ` Jarek Poplawski
2009-06-28 18:04 ` Oleg Nesterov
2009-06-28 21:48 ` Jarek Poplawski
2009-06-29 9:27 ` Jiri Olsa
2009-06-26 13:46 ` Oleg Nesterov
2009-06-25 23:18 ` Eric Dumazet
2009-06-26 1:50 ` Tejun Heo
2009-06-29 9:12 ` Andi Kleen
2009-06-29 9:24 ` Jiri Olsa
2009-06-29 16:59 ` Zan Lynx
2009-06-29 17:29 ` Andi Kleen [this message]
2009-07-01 3:39 ` Herbert Xu
2009-07-01 6:27 ` Andi Kleen
2009-07-01 7:03 ` Herbert Xu
2009-07-01 7:22 ` Andi Kleen
2009-07-01 8:31 ` Herbert Xu
2009-07-01 8:44 ` Jiri Olsa
2009-07-01 10:58 ` Herbert Xu
2009-07-01 13:07 ` Herbert Xu
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