From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f172.google.com (mail-qc0-f172.google.com [209.85.216.172]) by kanga.kvack.org (Postfix) with ESMTP id 8BA916B0036 for ; Thu, 15 May 2014 07:24:35 -0400 (EDT) Received: by mail-qc0-f172.google.com with SMTP id l6so1505557qcy.31 for ; Thu, 15 May 2014 04:24:35 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id 33si2378023qgi.174.2014.05.15.04.24.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 May 2014 04:24:35 -0700 (PDT) Date: Thu, 15 May 2014 04:24:33 -0700 From: Christoph Hellwig Subject: Re: [PATCH] Sync only the requested range in msync Message-ID: <20140515112433.GA21206@infradead.org> References: <1395961361-21307-1-git-send-email-matthew.r.wilcox@intel.com> <20140423141115.GA31375@infradead.org> <20140512163948.0b365598e1e4d0b06dea3bc6@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Jeff Moyer Cc: Andrew Morton , Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, willy@linux.intel.com On Tue, May 13, 2014 at 09:31:01AM -0400, Jeff Moyer wrote: > FWIW, I think we should apply the patch. Anyone using the API properly > will not get the desired result, and it could have a negative impact on > performance. The man page is very explicit on what you should expect, > here. Anyone relying on undocumented behavior gets to keep both pieces > when it breaks. That said, I do understand your viewpoint, Andrew, > especially since it's so hard to get people to sync their data at all, > much less correctly. Agreed, we never made filesystems write out all data in the file system in fsync either just because ext3 behaved that way. And unlike that case I can't even see a good way to get msync wrong - you call it on the mapped region, so expecting it to write out data that isn't mapped at all seems rather odd. -- 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