From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D47BC433DB for ; Wed, 3 Mar 2021 15:53:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E41ED64EDC for ; Wed, 3 Mar 2021 15:53:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E41ED64EDC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5B62C8D0179; Wed, 3 Mar 2021 10:53:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 58C0E8D0157; Wed, 3 Mar 2021 10:53:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 47BE68D0179; Wed, 3 Mar 2021 10:53:58 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0006.hostedemail.com [216.40.44.6]) by kanga.kvack.org (Postfix) with ESMTP id 292028D0157 for ; Wed, 3 Mar 2021 10:53:58 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C71CC18016115 for ; Wed, 3 Mar 2021 15:53:57 +0000 (UTC) X-FDA: 77879008914.26.0FC6D86 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf03.hostedemail.com (Postfix) with ESMTP id 3E9C4C0007C3 for ; Wed, 3 Mar 2021 15:53:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ZH1C/G3uhNYXYHLyRoi9Xr5MI5GoH8WMp548MeloCis=; b=Crw7M0Lc+wxp42QJC8iqj/AodZ RBoFd5Okwm21AmLXrF02/0bXsuEpYbm5LHfL2Hi+FVyTD2p0D9JOyaDVJ0fOOm6SLU9qXgUxtsEW4 g7x8hiSCt6uoXKbxfPiNyYOWUFcBedpQLmiwOz5fWSwBzQUv8DbiIr0eYB+h3Cvr2y/fzPb7xVu7k hsu2FoIEa0DE4nBW2VNJX150lB3Rdd08e/af9NuwOB0m2FT+sLStRlngPoQMnh6E+qQuXrQmv9lP9 MBPuAkOwWcIUVW89FiyXwFJU2zAh+tx95RRNjhPSU4A4XLXADV3NKgo3PKRisXjZnSvxEaJ+Gn/zf O1y/OVMA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lHSS4-002wEW-N2; Wed, 03 Mar 2021 14:26:14 +0000 Date: Wed, 3 Mar 2021 14:26:12 +0000 From: Matthew Wilcox To: Christoph Lameter Cc: Xunlei Pang , Vlastimil Babka , Wen Yang , Roman Gushchin , Pekka Enberg , Konstantin Khlebnikov , David Rientjes , linux-kernel@vger.kernel.org, "linux-mm@kvack.org" Subject: Re: [PATCH v2 3/3] mm/slub: Use percpu partial free counter Message-ID: <20210303142612.GC2723601@casper.infradead.org> References: <1597061872-58724-1-git-send-email-xlpang@linux.alibaba.com> <1597061872-58724-4-git-send-email-xlpang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 3E9C4C0007C3 X-Stat-Signature: 5rpw3fpj3p83ygm3a7o69x5d3tt7bbwd Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf03; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614786824-520273 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Mar 02, 2021 at 10:14:53AM +0100, Christoph Lameter wrote: > On Mon, 10 Aug 2020, Xunlei Pang wrote: > > - atomic_long_t partial_free_objs; > > + atomic_long_t __percpu *partial_free_objs; > > A percpu counter is never atomic. Just use unsigned long and use this_cpu > operations for this thing. That should cut down further on the overhead. What about allocations from interrupt context? Should this be a local_t instead?