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=-0.6 required=3.0 tests=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 AB9A8C38A2A for ; Fri, 8 May 2020 11:24:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D9E8206D6 for ; Fri, 8 May 2020 11:24:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qWtc8D7+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbgEHLY6 (ORCPT ); Fri, 8 May 2020 07:24:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726616AbgEHLY6 (ORCPT ); Fri, 8 May 2020 07:24:58 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D0C5C05BD43 for ; Fri, 8 May 2020 04:24:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=NxQcpIelyEQesB4Sm1aLDUu9bMqSHC3VF1eV1UfASUg=; b=qWtc8D7+0/9xVqdUbP7k/6JIm1 RDfSxGbjCusifjScBAtY+UU5VWoPHynFdOxj/MsCdD5rnKX1Irb6qQJf7hiS2eeS/9R/Ihz5A3Lmz /13vLvj4Q5IMF/T+/Wsg1Lnd4bK7pB9BG7Om74roMn9fwuqLy496RA3Dp2PBFaCWBAZ2kUoO9KMd6 Ih22+gY1uwLRktvcICmPI9Rt4D+MdaJY6Z4Y3DYnYtsdMc1d83bWq8eqXda8eGKZNrcsMym/hdjgg URCcDV+sJnTVaNeSYzvbBlB1uhsi+gXtV99DneCrhZtavmpUM7IwaFA25iYsm/oHfxEgrf3i2JLyf 6o7hlM8A==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jX17Y-0006Gg-8m; Fri, 08 May 2020 11:24:48 +0000 Date: Fri, 8 May 2020 04:24:48 -0700 From: Matthew Wilcox To: Feng Tang Cc: Andrew Morton , Michal Hocko , Johannes Weiner , Mel Gorman , Kees Cook , Luis Chamberlain , Iurii Zaikin , andi.kleen@intel.com, tim.c.chen@intel.com, dave.hansen@intel.com, ying.huang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mm: adjust vm_committed_as_batch according to vm overcommit policy Message-ID: <20200508112448.GP16070@bombadil.infradead.org> References: <1588922717-63697-1-git-send-email-feng.tang@intel.com> <1588922717-63697-4-git-send-email-feng.tang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1588922717-63697-4-git-send-email-feng.tang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 08, 2020 at 03:25:17PM +0800, Feng Tang wrote: > +void mm_compute_batch(void) > { > u64 memsized_batch; > s32 nr = num_present_cpus(); > s32 batch = max_t(s32, nr*2, 32); > - > - /* batch size set to 0.4% of (total memory/#cpus), or max int32 */ > - memsized_batch = min_t(u64, (totalram_pages()/nr)/256, 0x7fffffff); > + unsigned long ram_pages = totalram_pages(); > + > + /* > + * For policy of OVERCOMMIT_NEVER, set batch size to 0.4% > + * of (total memory/#cpus), and lift it to 6.25% for other > + * policies to easy the possible lock contention for percpu_counter > + * vm_committed_as, while the max limit is INT_MAX > + */ > + if (sysctl_overcommit_memory == OVERCOMMIT_NEVER) > + memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX); > + else > + memsized_batch = min_t(u64, ram_pages/nr/16, INT_MAX); > > vm_committed_as_batch = max_t(s32, memsized_batch, batch); > + printk("vm_committed_as_batch = %d\n", vm_committed_as_batch); > } You left a debugging printk in ...