Date: Sat, 26 Mar 2005 13:29:03 +0100
From: Willy Tarreau <willy@w.ods.org>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Marcelo Tosatti <marcelo.tosatti@cyclades.com>,
       linux-kernel@vger.kernel.org, davej@redhat.com
Subject: Re: Linux 2.4.30-rc2
Message-ID: <20050326122903.GB14756@alpha.home.local>
References: <20050326004631.GC17637@logos.cnet> <20050326113426.GO30052@alpha.home.local> <1111837579.8042.5.camel@laptopd505.fenrus.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1111837579.8042.5.camel@laptopd505.fenrus.org>
User-Agent: Mutt/1.4i
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 986
Lines: 24

On Sat, Mar 26, 2005 at 12:46:19PM +0100, Arjan van de Ven wrote:
> On Sat, 2005-03-26 at 12:34 +0100, Willy Tarreau wrote:
> > Marcelo,
> > 
> > just another one and that's all. Zachary Amsden found an unconditional
> > write to a debug register in the signal delivery path which is only
> > needed when we use a breakpoint. This is a very expensive operation on
> > x86, and doing it conditionnaly enhanced signal delivery speed by 33%
> > for him.
> 
> this sounds rather risky for this late in the game; heck it sounds risky
> in 2.4 period. This code changed a lot in 2.6 so just a plain backport
> is by no means risk free, while the effect of a wrong debug register can
> even have security impact. 

ok, that's a good reason.

Willy

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/