From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 6 May 2008 07:53:23 -0700 (PDT) From: Linus Torvalds Subject: Re: [patch 2/2] fix SMP data race in pagetable setup vs walking In-Reply-To: <20080506095138.GE10141@wotan.suse.de> Message-ID: References: <20080505112021.GC5018@wotan.suse.de> <20080505121240.GD5018@wotan.suse.de> <20080506095138.GE10141@wotan.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Hugh Dickins , linux-arch@vger.kernel.org, Linux Memory Management List , Paul McKenney List-ID: On Tue, 6 May 2008, Nick Piggin wrote: > > Right. As the comment says, the x86 stuff is kind of a "reference" > implementation, although if you prefer it isn't there, then I I can > easily just make it alpha only. If there really was a point in teaching people about "read_barrier_depends()", I'd agree that it's probably good to have it as a reference in the x86 implementation. But since alpha is the only one that needs it, and is likely to remain so, it's not like we ever want to copy that code to anything else, and it really is better to make it alpha-only if the code is so much uglier. Maybe just a comment? As to the ACCESS_ONCE() thing, thinking about it some more, I doubt it really matters. We're never going to change pgd anyway, so who cares if we access it once or a hundred times? Linus -- 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