From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: pagefault scalability patches From: Benjamin Herrenschmidt In-Reply-To: References: <20050817151723.48c948c7.akpm@osdl.org> <4303EBC2.4030603@yahoo.com.au> <430448F8.3090502@yahoo.com.au> Content-Type: text/plain Date: Mon, 22 Aug 2005 12:04:53 +1000 Message-Id: <1124676293.5159.4.camel@gaston> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Nick Piggin , Andrew Morton , Linus Torvalds , Hugh Dickins , Nick Piggin , linux-mm@kvack.org List-ID: On Thu, 2005-08-18 at 09:17 -0700, Christoph Lameter wrote: > On Thu, 18 Aug 2005, Nick Piggin wrote: > > > Nick Piggin wrote: > > > > > If the big ticket item is taking the ptl out of the anonymous fault > > > path, then we probably should forget my stuff > > > > ( for now :) ) > > I think we can gradually work atomic operations into various code paths > where this will be advantageous and your work may be a very important base > to get there. Don't forget however that when doing things like tearing down page tables, it's a lot more efficient to take 1 lock, then do a bunch of things non-atomically, then drop that lock. At least on PPC, the cost of a lock is approx. equivalent to the cost of an atomic, and is measurable on such things. That said, I think your approach for the anonymous page case is a good first step for now. I'll have to adapt ppc64 to it but it shouldn't be too hard. Ben. -- 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/ . Don't email: email@kvack.org