From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 9 May 2006 17:24:28 -0700 (PDT) From: Linus Torvalds Subject: Re: [RFC][PATCH 1/3] tracking dirty pages in shared mappings -V4 In-Reply-To: <446101BA.4000208@google.com> Message-ID: References: <1146861313.3561.13.camel@lappy> <445CA22B.8030807@cyberone.com.au> <1146922446.3561.20.camel@lappy> <445CA907.9060002@cyberone.com.au> <1146929357.3561.28.camel@lappy> <1147116034.16600.2.camel@lappy> <1147207458.27680.19.camel@lappy> <17505.267.931504.918245@wombat.chubb.wattle.id.au> <446101BA.4000208@google.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Martin Bligh Cc: Peter Chubb , Peter Zijlstra , Christoph Lameter , Nick Piggin , Andi Kleen , Rohit Seth , Andrew Morton , hugh@veritas.com, riel@redhat.com, andrea@suse.de, arjan@infradead.org, apw@shadowen.org, mel@csn.ul.ie, marcelo@kvack.org, anton@samba.org, paulmck@us.ibm.com, linux-mm List-ID: On Tue, 9 May 2006, Martin Bligh wrote: > Peter Chubb wrote: > > > > What does this do to performance on TPC workloads? How many extra > > faults are there likely to be? > > They all use large pages anyway ... Yes, but we should really answer that question anyway. I don't think anybody has really objected to this patch series, and it clearly seems to fix something (if nothing else, then Peter's test-program ;), and for fairly obvious reasons _I_ approve of it. But I've been asking people to benchmark it anyway. Becuase it _will_ hurt users of shared writable mappings, even if it's hopefully less of an issue today thanks to large pages. Now, the fact that it will hurt them is not a total disaster, since we already know that there are ways to mitigate it. However, it's still true that we should have the numbers, if only to perhaps be able to say that we don't care. Linus -- 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