From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [PATCH 11/12] vmscan: Write out dirty pages in batch Date: Tue, 15 Jun 2010 21:20:18 +1000 Message-ID: <20100615112018.GL6138@laptop> References: <20100614231144.GG6590@dastard> <20100614162143.04783749.akpm@linux-foundation.org> <20100615003943.GK6590@dastard> <20100614183957.ad0cdb58.akpm@linux-foundation.org> <20100615032034.GR6590@dastard> <20100614211515.dd9880dc.akpm@linux-foundation.org> <20100615063643.GS6590@dastard> <20100615102822.GA4010@ioremap.net> <20100615105538.GI6138@laptop> <20100615111026.GF31051@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Evgeniy Polyakov , Dave Chinner , Andrew Morton , Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Chris Mason , Rik van Riel , Johannes Weiner , KAMEZAWA Hiroyuki To: Christoph Hellwig Return-path: Content-Disposition: inline In-Reply-To: <20100615111026.GF31051@infradead.org> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Tue, Jun 15, 2010 at 07:10:26AM -0400, Christoph Hellwig wrote: > On Tue, Jun 15, 2010 at 08:55:38PM +1000, Nick Piggin wrote: > > > > What I do in fsblock is to maintain a block-nr sorted tree of dirty > > blocks. This works nicely because fsblock dirty state is properly > > synchronized with page dirty state. So writeout can just walk this in > > order and it provides pretty optimal submission pattern of any > > interleavings of data and metadata. No need for buffer boundary or > > hacks like that. (needs some intelligence for delalloc, though). > > I think worrying about indirect blocks really doesn't matter much > these days. For one thing extent based filesystems have a lot less > of these, and second for a journaling filesystem we only need to log > modification to the indirect blocks and not actually write them back > in place during the sync. At least for XFS the actual writeback can > happen a lot later, as part of the ordered list of delwri buffers. That's true, more importantly I meant any interleavings of data from more than one file too. -- 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