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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 6CE74C35247 for ; Mon, 3 Feb 2020 21:30:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36EBC2086A for ; Mon, 3 Feb 2020 21:30:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="KobgtCTP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726287AbgBCVaM (ORCPT ); Mon, 3 Feb 2020 16:30:12 -0500 Received: from mail-lj1-f196.google.com ([209.85.208.196]:37934 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727072AbgBCVaL (ORCPT ); Mon, 3 Feb 2020 16:30:11 -0500 Received: by mail-lj1-f196.google.com with SMTP id w1so16284064ljh.5 for ; Mon, 03 Feb 2020 13:30:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ySSbnLN31i7Gv0dEujqlmedo6RywQfw4YrrrpttJLgk=; b=KobgtCTPqTOidmxNwdxQ0hjvbnszX+R4RWcWLWxJ+uvTDI/rP69kW8duPgWbHo1LVu Sai4Dm4sazBGzwERWccFEXaI598eq6EWecYp34MW8ILJVsyleE407qEGsPN5qJ4lgyQ/ 8K7jri+GO3U75nnDYdlociAEKfXothG/+7X7ABSQeFCAAQT2t8Iss0GJiF9iv6h6I4UP D3lM3GXquVFErJ1lYr6xVbbVnSqatuWVwE8qbSdpnrtqyce3rATRSAmpPf7mROafnEyP VBMpp8JU2l/Tn2SByXuuWLdhBDykIbMvQ4LgrqFcuIVRgpsVbRcK9eCcpoO2Zlcy6tZZ SvDA== 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=ySSbnLN31i7Gv0dEujqlmedo6RywQfw4YrrrpttJLgk=; b=sQqWEkseHybX5UmVBbhN6zv51fA0dSxyojITz7VY5XnaKRmyAcbQMrvyNhkFwEvC/p n5OFO+eIrmT/4GuCpVyiFPY5yvg6Uff2bJKxIbjhzQwzpGGv/PYq4aZ3YNBZT/jk7srT lJnizIlE9bXizQm0LZd2nCnziRtY0RgHTpfTAsy8mMHbsi5EG+xOFwgLpzp4sJ49xE7T BhH58rMX/LefrUxuab30fSlpg2hr7j3GpP54kqcnLHH4xPsszDwiKe27vgaVo01GQFaX 7SRp4isJN4B0cIVs6dveXSMLBePMt/eHgKu/TSn47JMepMwYHPaCoKFHNRk4rptglPC+ 5R0g== X-Gm-Message-State: APjAAAXbcsdFQwQ5ZZpuTS9ajWtxtj/SIN2gyzE/Itk3IlFbKL5y10yO RAAPZWpGW+MCo5CfBydFzMiLJw== X-Google-Smtp-Source: APXvYqzZ8QqSIH6wmy7AnrvnvdyFJ/nn3W6Ulq1Wz+pKu0iT1z5Hjs/H587kjfOvuXRpwubRreoNeQ== X-Received: by 2002:a2e:9c85:: with SMTP id x5mr15245701lji.50.1580765409905; Mon, 03 Feb 2020 13:30:09 -0800 (PST) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id k24sm12450538ljj.27.2020.02.03.13.30.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Feb 2020 13:30:09 -0800 (PST) Received: by box.localdomain (Postfix, from userid 1000) id 19070100AF6; Tue, 4 Feb 2020 00:30:22 +0300 (+03) Date: Tue, 4 Feb 2020 00:30:22 +0300 From: "Kirill A. Shutemov" To: John Hubbard Cc: Andrew Morton , Al Viro , Christoph Hellwig , Dan Williams , Dave Chinner , Ira Weiny , Jan Kara , Jason Gunthorpe , Jonathan Corbet , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Michal Hocko , Mike Kravetz , Shuah Khan , Vlastimil Babka , Matthew Wilcox , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-rdma@vger.kernel.org, linux-mm@kvack.org, LKML Subject: Re: [PATCH v3 10/12] mm/gup: /proc/vmstat: pin_user_pages (FOLL_PIN) reporting Message-ID: <20200203213022.rltjlohvaswk32ln@box.shutemov.name> References: <20200201034029.4063170-1-jhubbard@nvidia.com> <20200201034029.4063170-11-jhubbard@nvidia.com> <20200203135320.edujsfjwt5nvtiit@box> <0425e1e6-f172-91df-2251-7583fcfed3e6@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0425e1e6-f172-91df-2251-7583fcfed3e6@nvidia.com> Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Mon, Feb 03, 2020 at 01:04:04PM -0800, John Hubbard wrote: > On 2/3/20 5:53 AM, Kirill A. Shutemov wrote: > > On Fri, Jan 31, 2020 at 07:40:27PM -0800, John Hubbard wrote: > >> diff --git a/mm/gup.c b/mm/gup.c > >> index c10d0d051c5b..9fe61d15fc0e 100644 > >> --- a/mm/gup.c > >> +++ b/mm/gup.c > >> @@ -29,6 +29,19 @@ struct follow_page_context { > >> unsigned int page_mask; > >> }; > >> > >> +#ifdef CONFIG_DEBUG_VM > > > > Why under CONFIG_DEBUG_VM? There's nothing about this in the cover letter. > > > > Early on, gup_benchmark showed a really significant slowdown from using these > counters. And I don't doubt that it's still the case. > > I'll re-measure and add a short summary and a few numbers to the patch commit > description, and to the v4 cover letter. Looks like you'll show zeros for these counters if debug is off. It can be confusing to the user. I think these counters should go away if you don't count them. -- Kirill A. Shutemov