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,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 CA938C54FCE for ; Mon, 23 Mar 2020 16:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 992782076A for ; Mon, 23 Mar 2020 16:51:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="I8nEQQSW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727624AbgCWQvO (ORCPT ); Mon, 23 Mar 2020 12:51:14 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:46010 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727067AbgCWQvO (ORCPT ); Mon, 23 Mar 2020 12:51:14 -0400 Received: by mail-qt1-f196.google.com with SMTP id t17so2119853qtn.12 for ; Mon, 23 Mar 2020 09:51:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=LWBMOpdQ6RM6tzOn/8vWjeIgj8g8a5I1STuJsGCjRo8=; b=I8nEQQSWkjtHSqP1oR4eghgEG3cRUnPlE+gN/nLMpRir0NoJuL2+OW3Ih9ju54o1mp AHaALAKLIoIOXw3pyp+wb+fJADkm3tYqh79N43FfTLB1ikS2bppY8ZfEK12nDPlFafTR afvhXue9Jb+JdKlFwqQUl7+WlJ4l6hBwCpYmW2Y9CVnf27BQDsCNeFCqRTsDzKw+Um4T Kow9JvP65D9EhMJ0W7QNwbOxXYn/7byquVJrjEazzOPYurkG1c7A0JhF+VGWJzaw64hJ Okj2CwJ0nbbDIQ4KtMeCRus9UkOVuaENlWnzezFt2qWFp1nNrsSfj+rMW0+cHuC5+4qQ dDqQ== 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=LWBMOpdQ6RM6tzOn/8vWjeIgj8g8a5I1STuJsGCjRo8=; b=ioyvttyH1/mbUh4Xp/WW84mQYGQrgVbUZJI76NdaV+9EC9D7zL9rqmvYwsHYcL1qk3 bMwK7AFQ3mlhT+ffiWM43CyA/NqAwrRgGukR3TcIs23XxSA+T5ES2qL0x9YV4hQNQIEO cbknzvX20ucN3H9D2oMBQ0mHF9DIQTZLvvp7piAIT3KfkKoRpPAAMT/EUASTpYRF86F8 uragmhc9OXYfh8ihB9oVi5BE65dJzC826jnNaFaBkwTgglcGquKo+InXELAbEIt+BfhQ YVExMfIGrQEo2xaKD4oFBAayK39tsE5ia4oBueCNqKnC5JA4bX8bx5Ksu9mvCcRfFP7e qDcA== X-Gm-Message-State: ANhLgQ1lEHdySY5JNesmnK7cuWy/Oj0adztecsj6NgK17QUAjC7b93DF uz6/FnkFFZeLIILZQ8RJFgdcU3T+xOo= X-Google-Smtp-Source: ADFU+vsVno42d9S3diBfWFL38XIfIgaPdPcxiMkRilrh1GpMhoHWHq7xqGvY4ajHi7WGL965oPHLWA== X-Received: by 2002:ac8:6043:: with SMTP id k3mr22532957qtm.336.1584982273059; Mon, 23 Mar 2020 09:51:13 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:a9a9]) by smtp.gmail.com with ESMTPSA id l45sm12547211qtb.8.2020.03.23.09.51.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2020 09:51:12 -0700 (PDT) Date: Mon, 23 Mar 2020 12:51:11 -0400 From: Johannes Weiner To: js1304@gmail.com Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Hugh Dickins , Minchan Kim , Vlastimil Babka , Mel Gorman , kernel-team@lge.com, Joonsoo Kim Subject: Re: [PATCH v4 5/8] mm/workingset: handle the page without memcg Message-ID: <20200323165111.GC204561@cmpxchg.org> References: <1584942732-2184-1-git-send-email-iamjoonsoo.kim@lge.com> <1584942732-2184-6-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1584942732-2184-6-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 23, 2020 at 02:52:09PM +0900, js1304@gmail.com wrote: > From: Joonsoo Kim > > When implementing workingset detection for anonymous page, I found > some swapcache pages with NULL memcg. They are brought in by swap > readahead and nobody has touched it. > > The idea behind the workingset code is to tell on page fault time > whether pages have been previously used or not. Since this page > hasn't been used, don't store a shadow entry for it; when it later > faults back in, we treat it as the new page that it is. > > Signed-off-by: Joonsoo Kim Acked-by: Johannes Weiner