From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 7/6] Lost bits - fix PG_writeback vs PG_private race in NFS From: Peter Zijlstra In-Reply-To: <1156536687.5927.25.camel@localhost> References: <20060825153709.24254.28118.sendpatchset@twins> <1156523815.16027.43.camel@taijtu> <1156536687.5927.25.camel@localhost> Content-Type: text/plain Date: Fri, 25 Aug 2006 22:44:21 +0200 Message-Id: <1156538662.26945.21.camel@lappy> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Trond Myklebust Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Rik van Riel List-ID: On Fri, 2006-08-25 at 16:11 -0400, Trond Myklebust wrote: > On Fri, 2006-08-25 at 18:36 +0200, Peter Zijlstra wrote: > > Make sure we clear PG_writeback after we clear PG_private, otherwise > > weird and wonderfull stuff will happen. > > > NACK. > > Look carefully at the case of unstable writes: your patch does nothing > to guarantee that PG_writeback is cleared after PG_private for that > case. Ah, right. Thanks for pointing this out. > Anyhow, you don't explain exactly what is wrong with clearing > PG_writeback before PG_private. Yes, this was a rather hasty patch, I was mortified to find that I missed a few changes and my patch-set would crash instantly someone would try it. The VM doesn't really like PG_private set on PG_swapcache pages, I guess I'll have to rectify that and leave the NFS behaviour as is. Will correct this in the next round. Thanks for the feedback, Peter -- 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