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=-1.0 required=3.0 tests=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 CB1D8C433E0 for ; Fri, 15 May 2020 07:44:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8A8ED206F4 for ; Fri, 15 May 2020 07:44:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A8ED206F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2690A90000C; Fri, 15 May 2020 03:44:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 21B278E0005; Fri, 15 May 2020 03:44:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 12F5590000C; Fri, 15 May 2020 03:44:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0147.hostedemail.com [216.40.44.147]) by kanga.kvack.org (Postfix) with ESMTP id ECE648E0005 for ; Fri, 15 May 2020 03:44:46 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 9CBE78248047 for ; Fri, 15 May 2020 07:44:46 +0000 (UTC) X-FDA: 76818166572.14.cows73_63e249125074c X-HE-Tag: cows73_63e249125074c X-Filterd-Recvd-Size: 3138 Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Fri, 15 May 2020 07:44:46 +0000 (UTC) Received: by mail-wm1-f66.google.com with SMTP id u188so1520983wmu.1 for ; Fri, 15 May 2020 00:44:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=vJVWJQVk8CciTsSCvsqJGG8XKk2NT2HP/Zje3wxePpk=; b=nngDgPIT+1LPbAmKdX8jPatqxBxf9dvyjUCa2/x9lkU1pjepJllDnlX1aesR1kX8kT qpN8T6t4Jpx2rTifLa3yFZ440H6Atj/rXy6uR7NrXN19Ye/GBqtsJ0a65pE8fjyj1RVL sxGmHOEzJltIKbWTva1q/t/8X85/P6Cb6zTBPHn52DPnPAAOWqfb/fBuV0yfBh+m8Bsr 5JNAlQ6qklWivDfSvebMJr/d6AhOJZLAE69SGsxD8k+boHt/d7w0TKEDMhAgZvuWS9V7 DEAokE5aLwN04MK91zeD6MykU1BDgv+TksZyRgKAPIYtUOzhyrx+oqL7wg7SioKKwuTb TuFQ== X-Gm-Message-State: AOAM531PuvRWDraiNab0XptYzmUcrNMkjslvGgMMbc0gGyXARc7fR5+s ocyfgVwzHNIfK7mSwT0ueZo= X-Google-Smtp-Source: ABdhPJzvvHdgX5ui4nSJTmyuDZ8V7G9BS6vKsmATdulV+5BVtxjVEsfdhBS0PT9CUX0cVS6RBi/lDg== X-Received: by 2002:a05:600c:1403:: with SMTP id g3mr2660839wmi.51.1589528685290; Fri, 15 May 2020 00:44:45 -0700 (PDT) Received: from localhost (ip-37-188-249-36.eurotel.cz. [37.188.249.36]) by smtp.gmail.com with ESMTPSA id p17sm5856361wmi.3.2020.05.15.00.44.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 00:44:44 -0700 (PDT) Date: Fri, 15 May 2020 09:44:43 +0200 From: Michal Hocko To: Feng Tang Cc: Andrew Morton , Johannes Weiner , Matthew Wilcox , 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: <20200515074443.GI29153@dhcp22.suse.cz> 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> 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 Fri 08-05-20 15:25:17, Feng Tang wrote: > When checking a performance change for will-it-scale scalability > mmap test [1], we found very high lock contention for spinlock of > percpu counter 'vm_committed_as': Btw. you are focusing on a microbenchmark here but I believe that there are non-synthetic worklaods which would benefit from a larger batch. E.g. large in memory databases which do large mmaps during startups from multiple threads. -- Michal Hocko SUSE Labs