From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id C91DC6B01D1 for ; Tue, 18 May 2010 12:00:55 -0400 (EDT) Date: Wed, 19 May 2010 02:00:51 +1000 From: Nick Piggin Subject: Re: Unexpected splice "always copy" behavior observed Message-ID: <20100518160051.GK2516@laptop> References: <20100518153440.GB7748@Krystal> <20100518155135.GJ2516@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Mathieu Desnoyers , Peter Zijlstra , Steven Rostedt , Frederic Weisbecker , Pierre Tardy , Ingo Molnar , Arnaldo Carvalho de Melo , Tom Zanussi , Paul Mackerras , linux-kernel@vger.kernel.org, arjan@infradead.org, ziga.mahkovec@gmail.com, davem , linux-mm@kvack.org, Andrew Morton , KOSAKI Motohiro , Tejun Heo , Jens Axboe , Linus Torvalds List-ID: On Tue, May 18, 2010 at 10:56:24AM -0500, Christoph Lameter wrote: > On Wed, 19 May 2010, Nick Piggin wrote: > > > What would be needed is to have filesystem maintainers go through and > > enable it on a case by case basis. It's trivial for tmpfs/ramfs type > > filesystems and I have a patch for those, but I never posted it on.yet. > > Even basic buffer head filesystems IIRC get a little more complex -- > > but we may get some milage just out of invalidating the existing > > pagecache rather than getting fancy and trying to move buffers over > > to the new page. > > There is a "migration" address space operation for moving pages. Page > migration requires that in order to be able to move dirty pages. Can > splice use that? Hmm yes I didn't think of that, it probably could. -- 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