From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 3/3] nfs: use ->mmap_prepare() to avoid an AB-BA deadlock From: Trond Myklebust In-Reply-To: <20071114222448.GE31048@wotan.suse.de> References: <20071114200136.009242000@chello.nl> <20071114201528.514434000@chello.nl> <20071114212246.GA31048@wotan.suse.de> <1195075905.22457.3.camel@lappy> <1195076485.7584.66.camel@heimdal.trondhjem.org> <1195077034.22457.6.camel@lappy> <1195078730.7584.86.camel@heimdal.trondhjem.org> <20071114222448.GE31048@wotan.suse.de> Content-Type: text/plain Date: Wed, 14 Nov 2007 17:53:48 -0500 Message-Id: <1195080828.7584.96.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, Linus Torvalds , Andrew Morton , Hugh Dickins List-ID: On Wed, 2007-11-14 at 23:24 +0100, Nick Piggin wrote: > mmap()s can be different from read in that the syscall may have little > relation to when the data gets used. But I guess it's still a best > effort thing. Fair enough. Agreed that mmap() is special and very problematic on NFS. However I can't see how we can improve on the existing models short of some significant protocol modifications, and so far, nobody has presented the IETF with a good case for why they need this level of cache consistency. Cheers Trond -- 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