From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757141Ab0HIQeh (ORCPT ); Mon, 9 Aug 2010 12:34:37 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:59394 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754597Ab0HIQef (ORCPT ); Mon, 9 Aug 2010 12:34:35 -0400 Subject: Re: [PATCH] kvm: make mmu_shrink() fit shrinker's requirement From: Dave Hansen To: Avi Kivity Cc: Lai Jiangshan , Marcelo Tosatti , LKML , kvm@vger.kernel.org In-Reply-To: <4C5A844C.60105@redhat.com> References: <4C591313.50402@cn.fujitsu.com> <4C5A844C.60105@redhat.com> Content-Type: text/plain; charset="ANSI_X3.4-1968" Date: Mon, 09 Aug 2010 09:34:30 -0700 Message-ID: <1281371670.9442.16947.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2010-08-05 at 12:28 +0300, Avi Kivity wrote: > On 08/04/2010 10:13 AM, Lai Jiangshan wrote: > > mmu_shrink() should attempt to free @nr_to_scan entries. > > > > This conflicts with Dave's patchset. > > Dave, what's going on with those patches? They're starting to smell. The hardware and test rig that actually found the original scalability problem is a bit contended with issues at the moment, so I've been unable to get the original issue reproduced. But, I think the patches should be able to stand on their own. Even in my testing, it's obvious that the shrinker code gets queries (via nr_to_shrink=0) *way* more often than it's actually called upon to shrink things. Even if we have to come back with some more patches than this in the future for the original problem that was found, we should feel confident that this patch set is worthwhile and does some real, quantifiable good on its own. I'll go and immediately test that the first four patches in the series are still behaving themselves in the way that I expect. -- Dave