From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755625Ab2JPDXf (ORCPT ); Mon, 15 Oct 2012 23:23:35 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:60747 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751529Ab2JPDXd (ORCPT ); Mon, 15 Oct 2012 23:23:33 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.8.4 Message-ID: <507CD2FA.8000009@jp.fujitsu.com> Date: Tue, 16 Oct 2012 12:22:34 +0900 From: Kamezawa Hiroyuki User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 MIME-Version: 1.0 To: Glauber Costa CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Mel Gorman , Suleiman Souhlal , Tejun Heo , cgroups@vger.kernel.org, Michal Hocko , Johannes Weiner , Greg Thelen , devel@openvz.org, Frederic Weisbecker Subject: Re: [PATCH v4 02/14] memcg: Reclaim when more than one page needed. References: <1349690780-15988-1-git-send-email-glommer@parallels.com> <1349690780-15988-3-git-send-email-glommer@parallels.com> In-Reply-To: <1349690780-15988-3-git-send-email-glommer@parallels.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2012/10/08 19:06), Glauber Costa wrote: > From: Suleiman Souhlal > > mem_cgroup_do_charge() was written before kmem accounting, and expects > three cases: being called for 1 page, being called for a stock of 32 > pages, or being called for a hugepage. If we call for 2 or 3 pages (and > both the stack and several slabs used in process creation are such, at > least with the debug options I had), it assumed it's being called for > stock and just retried without reclaiming. > > Fix that by passing down a minsize argument in addition to the csize. > > And what to do about that (csize == PAGE_SIZE && ret) retry? If it's > needed at all (and presumably is since it's there, perhaps to handle > races), then it should be extended to more than PAGE_SIZE, yet how far? > And should there be a retry count limit, of what? For now retry up to > COSTLY_ORDER (as page_alloc.c does) and make sure not to do it if > __GFP_NORETRY. > > [v4: fixed nr pages calculation pointed out by Christoph Lameter ] > > Signed-off-by: Suleiman Souhlal > Signed-off-by: Glauber Costa > Reviewed-by: Kamezawa Hiroyuki > Acked-by: Michal Hocko > Acked-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki