From mboxrd@z Thu Jan 1 00:00:00 1970 In-reply-to: <20080730175406.GN20055@kernel.dk> (message from Jens Axboe on Wed, 30 Jul 2008 19:54:07 +0200) Subject: Re: [patch v3] splice: fix race with page invalidation References: <20080730175406.GN20055@kernel.dk> Message-Id: From: Miklos Szeredi Date: Wed, 30 Jul 2008 20:32:14 +0200 Sender: owner-linux-mm@kvack.org Return-Path: To: jens.axboe@oracle.com Cc: miklos@szeredi.hu, torvalds@linux-foundation.org, akpm@linux-foundation.org, nickpiggin@yahoo.com.au, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 30 Jul 2008, Jens Axboe wrote: > On Wed, Jul 30 2008, Miklos Szeredi wrote: > > On Wed, 30 Jul 2008, Linus Torvalds wrote: > > > On Wed, 30 Jul 2008, Miklos Szeredi wrote: > > > > > > > > There are no real disadvantages: splice() from a file was > > > > originally meant to be asynchronous, but in reality it only did > > > > that for non-readahead pages, which happen rarely. > > > > > > I still don't like this. I still don't see the point, and I still > > > think there is something fundamentally wrong elsewhere. > > You snipped the part where Linus objected to dismissing the async > nature, I fully agree with that part. > > > We discussed the possible solutions with Nick, and came to the > > conclusion, that short term (i.e. 2.6.27) this is probably the best > > solution. > > Ehm where? http://lkml.org/lkml/2008/7/7/476 > Nick also said that he didn't like removing the ->confirm() > bits as they are completely related to the async nature of splice. You > already submitted this exact patch earlier and it was nak'ed. That's not true. The resubmitted patch didn't remove the ->confirm() calls, which is what Nick objected to, I think. > > Long term sure, I have no problem with implementing async splice. > > > > In fact, I may even have personal interest in looking at splice, > > because people are asking for a zero-copy interface for fuse. > > > > But that is definitely not 2.6.27, so I think you should reconsider > > taking this patch, which is obviously correct due to its simplicity, > > and won't cause any performance regressions either. > > Then please just fix the issue, instead of removing the bits that make > this possible. I tried to fix it, but Nick didn't like my fix. Ideas are of course welcome. Thanks, Miklos -- 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