linux-kernel - Re: [patch] epoll use a single inode ...

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Message-ID: <20070309024606.GB24695@kryten>
Date:	Thu, 8 Mar 2007 20:46:06 -0600
From:	Anton Blanchard <anton@...ba.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Eric Dumazet <dada1@...mosbay.com>,
	Davide Libenzi <davidel@...ilserver.org>,
	Avi Kivity <avi@...o.co.il>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Al Viro <viro@...iv.linux.org.uk>
Subject: Re: [patch] epoll use a single inode ...


> Yeah, I'm not at all surprised. Any implementation of "prefetch" that 
> doesn't just turn into a no-op if the TLB entry doesn't exist (which makes 
> them weaker for *actual* prefetching) will generally have a hard time with 
> a NULL pointer. Exactly because it will try to do a totally unnecessary 
> TLB fill - and since most CPU's will not cache negative TLB entries, that 
> unnecessary TLB fill will be done over and over and over again..

Yeah this is exactly what we were seeing :)

Anton
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