Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755873AbYG3Sd1 (ORCPT ); Wed, 30 Jul 2008 14:33:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751462AbYG3SdR (ORCPT ); Wed, 30 Jul 2008 14:33:17 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:52071 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752678AbYG3SdQ (ORCPT ); Wed, 30 Jul 2008 14:33:16 -0400 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 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2015 Lines: 52 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/