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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E65A0C433F5 for ; Fri, 13 May 2022 18:18:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 62BFE6B0073; Fri, 13 May 2022 14:18:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5DC776B0075; Fri, 13 May 2022 14:18:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4CAF46B0078; Fri, 13 May 2022 14:18:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3D6E96B0073 for ; Fri, 13 May 2022 14:18:33 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 1DC0120D35 for ; Fri, 13 May 2022 18:18:33 +0000 (UTC) X-FDA: 79461530106.25.F38EE8D Received: from mail-lf1-f50.google.com (mail-lf1-f50.google.com [209.85.167.50]) by imf30.hostedemail.com (Postfix) with ESMTP id C762D800A8 for ; Fri, 13 May 2022 18:18:12 +0000 (UTC) Received: by mail-lf1-f50.google.com with SMTP id i10so15829387lfg.13 for ; Fri, 13 May 2022 11:18:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vf1FtPA3uZ9fNZZHz0tT+V/8nY+jDOr65GeC2+AetOw=; b=kOX5fU83tbza7tkLFD5Qtst3jj8jMJBUUEtWGt5bHRzM9gvyWqhUZ1UY5jg7RFchRL +lTt97KTpvLj8T9fPfRYxS8kMDgEH7UksVuOv3VwJovoy/PXJbHRk1LowXquhftlzrfR ETfAIBUeKgADAL29g4RVOM5PhC2nuPpZD/ZyaV+e/uIpnsQMM4RqlsgueK6nam1vai/1 Ia+wytfTY2PM0mCW2kW9hSQh+AwW5o/ZjXsF6Iq4NcaJ/fmOgpUcehpJXqmLNA8g1Lq0 ZNcbyEw8mY14coP0FO+8ufZLdYp3Evydg0t4fNhXw73KnmfK+ntaRmDfEl37fJ/QqSD0 LzNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vf1FtPA3uZ9fNZZHz0tT+V/8nY+jDOr65GeC2+AetOw=; b=HANSW11rEdxJt5cOLA8suwApOyPfV5fdr3/kR67CHWGzWBAuJupZhym2ZJnienqV4T NQlxkmsRxq788AKffsSKSx98Nx47GiimKUn2lY4kBObFCWBZPwb1fL61Rk38o7gJnUvT SXYfJ6nm2U3JWahIWV6+ZWA5jrlu3VjUKKCgENKOO3PB4WTfIp7RQBEwrSWXTehry63Q mT5U25qy/K+qR9srGpNnBXfWKuchSxbOv6q79ukCp8NIsFSjpaW/ksoDcJd7kmRFLbI3 f06C9Y3oLNXrM+EOnq7rJrhEtXgtUyVHr3UvE8ck1r64HvHoWauXVfeiAi6OEdXnYB6h RYuA== X-Gm-Message-State: AOAM533qrxg4SqLU6D0Te2aXP8yEfSHcdqPv70wMFElaE1Q49gezL5Yj tWwUX71X5+V+uHW9C6aXQBl4ed1Sv/bvr826fcv5mg== X-Google-Smtp-Source: ABdhPJx5EeI82hdkwh0QXNUA0hzYeHQrMozTDx+5gLh5/vl3sHY8AC59Pz8UpWDl0KNcVMdn6AGyAXeIt53AC2OGaKE= X-Received: by 2002:a05:6512:b0f:b0:474:18c:8b9e with SMTP id w15-20020a0565120b0f00b00474018c8b9emr4439246lfu.354.1652465910529; Fri, 13 May 2022 11:18:30 -0700 (PDT) MIME-Version: 1.0 References: <20220504214437.2850685-1-zokeefe@google.com> <20220504214437.2850685-8-zokeefe@google.com> <6f5fb43c-43c1-596f-77d1-7b314a25c6a5@google.com> In-Reply-To: <6f5fb43c-43c1-596f-77d1-7b314a25c6a5@google.com> From: "Zach O'Keefe" Date: Fri, 13 May 2022 11:17:53 -0700 Message-ID: Subject: Re: [PATCH v5 07/13] mm/khugepaged: add flag to ignore page young/referenced requirement To: David Rientjes Cc: Alex Shi , David Hildenbrand , Matthew Wilcox , Michal Hocko , Pasha Tatashin , Peter Xu , SeongJae Park , Song Liu , Vlastimil Babka , Yang Shi , Zi Yan , linux-mm@kvack.org, Andrea Arcangeli , Andrew Morton , Arnd Bergmann , Axel Rasmussen , Chris Kennelly , Chris Zankel , Helge Deller , Hugh Dickins , Ivan Kokshaysky , "James E.J. Bottomley" , Jens Axboe , "Kirill A. Shutemov" , Matt Turner , Max Filippov , Miaohe Lin , Minchan Kim , Patrick Xia , Pavel Begunkov , Thomas Bogendoerfer Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: r34aux37d48gnb38fdrfqf6oz65nnkgg X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: C762D800A8 X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=kOX5fU83; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf30.hostedemail.com: domain of zokeefe@google.com designates 209.85.167.50 as permitted sender) smtp.mailfrom=zokeefe@google.com X-HE-Tag: 1652465892-364752 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: Thanks for the review, David! On Thu, May 12, 2022 at 1:03 PM David Rientjes wrote: > > On Wed, 4 May 2022, Zach O'Keefe wrote: > > > Add enforce_young flag to struct collapse_control that allows context to > > ignore requirement that some pages in region being collapsed be young or > > referenced. Set this flag in khugepaged collapse context to preserve > > existing khugepaged behavior. > > > > This flag will be used (unset) when introducing madvise collapse > > context since here, the user presumably has reason to believe the > > collapse will be beneficial and khugepaged heuristics shouldn't tell > > the user they are wrong. > > > > Signed-off-by: Zach O'Keefe > > --- > > mm/khugepaged.c | 23 +++++++++++++++-------- > > 1 file changed, 15 insertions(+), 8 deletions(-) > > > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > > index ca730aec0e3e..b14807b7002e 100644 > > --- a/mm/khugepaged.c > > +++ b/mm/khugepaged.c > > @@ -90,6 +90,9 @@ struct collapse_control { > > /* Respect khugepaged_max_ptes_[none|swap|shared] */ > > bool enforce_pte_scan_limits; > > > > + /* Require memory to be young */ > > + bool enforce_young; > > + > > /* Num pages scanned per node */ > > int node_load[MAX_NUMNODES]; > > > > Small nit: is it possible to unify these into a single bool khugepaged > flag? > I think this is fine with a "enforce_page_heuristics" flag or something. Ofc, functionally unifying the flags is a noop, but I was trying to to avoid "if (khugepagd) .. else .." and, where possible, describe the variable properties of the collapse in struct collapse_control itself. If there's no objections, I'll make that change for v6. > Either way: > > Acked-by: David Rientjes