From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Phillips Subject: Re: [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race Date: Thu, 29 May 2003 19:15:22 +0200 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200305291915.22235.phillips@arcor.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins , "Paul E. McKenney" Cc: akpm@digeo.com, hch@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Thursday 29 May 2003 18:33, you wrote: > On Thu, 29 May 2003, Paul E. McKenney wrote: > > On Fri, May 23, 2003 at 11:42:02AM -0700, Paul E. McKenney wrote: > > > Exactly -- allows a ->nopage() to drop some lock to avoid races > > > between pagefault and either vmtruncate() or invalidate_mmap_range(). > > > This race (from the cross-host mmap viewpoint) is described in: > > > > > > http://marc.theaimsgroup.com/?l=linux-kernel&m=105286345316249&w=2 > > > > Rediffed for 2.5.70-mm1. > > Me? I much preferred your original, much sparer, nopagedone patch > (labelled "uglyh as hell" by hch). "me too". The fat patch that hits every fs to get rid of two lines and .5 cycles per no_page fault could be an epilogue (if/when it passes muster) to the little one that does the job and has already been thoroughly tested. I see both sides of the argument. The third side, not yet discussed, is the value of doing things incrementally, with widespread testing of the system at each step. Regards, Daniel -- 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: aart@kvack.org