From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45F6967F.4020002@yahoo.com.au> Date: Tue, 13 Mar 2007 23:18:07 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [QUICKLIST 0/4] Arch independent quicklists V2 References: <20070313071325.4920.82870.sendpatchset@schroedinger.engr.sgi.com> <20070313005334.853559ca.akpm@linux-foundation.org> <45F65ADA.9010501@yahoo.com.au> <20070313035250.f908a50e.akpm@linux-foundation.org> <45F685C6.8070806@yahoo.com.au> <20070313041551.565891b5.akpm@linux-foundation.org> <45F68B4B.9020200@yahoo.com.au> <20070313044756.b45649ac.akpm@linux-foundation.org> <45F69287.8040509@yahoo.com.au> <20070313051109.3215104b.akpm@linux-foundation.org> In-Reply-To: <20070313051109.3215104b.akpm@linux-foundation.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Andrew Morton wrote: >>On Tue, 13 Mar 2007 23:01:11 +1100 Nick Piggin wrote: >>Andrew Morton wrote: >>>It would be interesting to look at a) leave the page full of random garbage >>>if we're releasing the whole mm and b) return it straight to the page allocator. >> >>Well we have the 'fullmm' case, which avoids all the locked pte operations >>(for those architectures where hardware pt walking requires atomicity). > > > I suspect there are some tlb operations which could be skipped in that case > too. Depends on the tlb flush implementation. The generic one doesn't look like it is all that smart about optimising the fullmm case. It does skip some tlb flushing though. >>However we still have to visit those to-be-unmapped parts of the page table >>to find the pages and free them. So we still at least need to bring it into >>cache for the read... at which point, the store probably isn't a big burden. > > > It means all that data has to be written back. Yes, I expect it'll prove > to be less costly than the initial load. Still, it is something we could try. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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