From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [rfc] data race in page table setup/walking? From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org In-Reply-To: References: <20080429050054.GC21795@wotan.suse.de> Content-Type: text/plain Date: Wed, 30 Apr 2008 07:37:39 +1000 Message-Id: <1209505059.18023.193.camel@pasglop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Nick Piggin , Linus Torvalds , linux-arch@vger.kernel.org, Linux Memory Management List List-ID: On Tue, 2008-04-29 at 13:36 +0100, Hugh Dickins wrote: > > Ugh. It's just so irritating to introduce these blockages against > such a remote possibility (but there again, that's what so much of > kernel code has to be about). Is there any other way of handling it? Not that much overhead... I think smp_read_barrier_depends() is a nop on most archs no ? The data dependency between all the pointers takes care of ordering in many cases. So it boils down to smp_wmb's when setting which is not that expensive. Cheers, Ben. -- 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