From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx101.postini.com [74.125.245.101]) by kanga.kvack.org (Postfix) with SMTP id 4B3F46B0147 for ; Fri, 22 Jun 2012 03:12:50 -0400 (EDT) Received: by wibhr4 with SMTP id hr4so263265wib.8 for ; Fri, 22 Jun 2012 00:12:48 -0700 (PDT) Date: Fri, 22 Jun 2012 09:12:43 +0200 From: Ingo Molnar Subject: Re: [patch 3.5-rc3] mm, mempolicy: fix mbind() to do synchronous migration Message-ID: <20120622071243.GB22167@gmail.com> References: <20120621164606.4ae1a71d.akpm@linux-foundation.org> <20120621184536.6dd97746.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120621184536.6dd97746.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Linus Torvalds , David Rientjes , Mel Gorman , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Peter Zijlstra , Ingo Molnar * Andrew Morton wrote: > On Thu, 21 Jun 2012 17:46:52 -0700 Linus Torvalds wrote: > > > On Thu, Jun 21, 2012 at 4:46 PM, Andrew Morton > > wrote: > > > > > > I can't really do anything with this patch - it's a bug > > > added by Peter's "mm/mpol: Simplify do_mbind()" and added > > > to linux-next via one of Ingo's trees. > > > > > > And I can't cleanly take the patch over as it's all bound > > > up with the other changes for sched/numa balancing. > > > > I took the patch, it looked obviously correct (passing in a > > boolean was clearly crap). > > Ah, OK, the bug was actually "retained" by "mm/mpol: Simplify > do_mbind()". > > I do still ask what the plans are for that patchset.. Somewhat off topic, but the main sched/numa objections were over the mbind/etc. syscalls and the extra configuration space - we dropped those bits and just turned it all into an improved NUMA scheduling feature, as suggested by Peter and me in the original discussion. There were no objections to that approach so the reworked NUMA scheduling/balancing scheme is now in the scheduler tree (tip:sched/core). The mbind/etc. syscall changes and all the related cleanups, speedups and reorganization of the MM code are still in limbo. I dropped them with the rest of tip:sched/numa as nobody from the MM side expressed much interest in them and I wanted to keep things simple and not carry objected-to commits. We can revive them if there's interest and consensus. I suspect once we gather experience with the automatic NUMA scheduling feature we'll see whether it's worth exposing that to user-space as an ABI - or whether we should go back to random placement and forget about it all. Thanks, Ingo -- 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