From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="iso-8859-1" From: Daniel Phillips Subject: Re: [PATCH] Optimize away pte_chains for single mappings Date: Tue, 16 Jul 2002 06:50:56 +0200 References: <3D33371D.6003AAAE@zip.com.au> In-Reply-To: <3D33371D.6003AAAE@zip.com.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Rik van Riel , Matti Aarnio , Dave McCracken , Linux Memory Management List-ID: On Monday 15 July 2002 22:57, Andrew Morton wrote: > Daniel Phillips wrote: > > On Monday 15 July 2002 18:34, Rik van Riel wrote: > > > On Mon, 15 Jul 2002, Daniel Phillips wrote: > > > > > > > None of these cases apply, the low bit is always masked off before being > > > > used as a pointer. > > > > > > Too ugly to live. > > > > That's a nonargument. I presume you weren't able to think of a > > substantive reason. > > How about "Linus will roast our nuts if we do that"? Unless someone can come up with a rational argument, I'd be forced to conclude that Linus is superstitious. > Plus accessing the same storage with both atomic and non-atomic > ops may be a problem on some hardware. Qu'est-ce que ca veux dire? We're protected under the pte_chain lock are we not? > Let's wait until we run out of page flags first... Sure, I intend to lay claim to six of them in due course, that would leave a mere eight for posterity. Then there is the method I proposed for saving 8 bytes per pte_chain with the help of an overloaded pointer. In what way does that not turn the ugly duckling into a beautiful swan? -- Daniel -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/