From: David Howells <dhowells@redhat.com>
To: David Miller <davem@davemloft.net>
Cc: dhowells@redhat.com, cl@linux.com, tj@kernel.org,
akpm@linuxfoundation.org, netdev@vger.kernel.org,
linux-arch@vger.kernel.org, srostedt@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [guv v2 04/31] net: Replace __get_cpu_var uses
Date: Tue, 03 Sep 2013 21:39:28 +0100 [thread overview]
Message-ID: <7928.1378240768@warthog.procyon.org.uk> (raw)
In-Reply-To: <20130902.203355.117341085023152754.davem@davemloft.net>
David Miller <davem@davemloft.net> wrote:
> > Would it be possible to use __thread annotations for per-CPU
> > variables, I wonder?
>
> Paul Mackerras tried it on powerpc and you can't do it.
>
> The problem is that there is no way to tell the compiler that sched()
> and similar (potentially) change the thread pointer base.
>
> It really will cache pre-computed __thread pointer calculations across
> sched().
Yeah... I thought there might be something like that - but I could see x86_64
using %fs as a base.
David
next prev parent reply other threads:[~2013-09-03 20:39 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130826204351.725357339@linux.com>
2013-08-26 20:44 ` [guv v2 04/31] net: Replace __get_cpu_var uses Christoph Lameter
2013-09-02 21:35 ` David Howells
2013-09-03 3:33 ` David Miller
2013-09-03 14:21 ` Christoph Lameter
2013-09-03 20:39 ` David Howells [this message]
2013-09-03 14:20 ` Christoph Lameter
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