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 A5349C2D0E7 for ; Wed, 1 Apr 2020 08:31:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 734DE206F5 for ; Wed, 1 Apr 2020 08:31:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 734DE206F5 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 1E5F66B0099; Wed, 1 Apr 2020 04:31:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 16E416B009A; Wed, 1 Apr 2020 04:31:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 00DF46B009B; Wed, 1 Apr 2020 04:31:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0115.hostedemail.com [216.40.44.115]) by kanga.kvack.org (Postfix) with ESMTP id D9FDD6B0099 for ; Wed, 1 Apr 2020 04:31:48 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 94EE1180AE1A2 for ; Wed, 1 Apr 2020 08:31:48 +0000 (UTC) X-FDA: 76658617896.14.mom39_842ee2e33a55b X-HE-Tag: mom39_842ee2e33a55b X-Filterd-Recvd-Size: 2817 Received: from mail-wm1-f68.google.com (mail-wm1-f68.google.com [209.85.128.68]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Wed, 1 Apr 2020 08:31:48 +0000 (UTC) Received: by mail-wm1-f68.google.com with SMTP id f6so6122383wmj.3 for ; Wed, 01 Apr 2020 01:31:48 -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=WVdUIRS1ycLvk6rcBuIPpHGovPPX241fTsOlQTbUJ+g=; b=mKRPwKuc89J8uFb7y8iGh5kz/zdXIxitxYvS0Funi+wa4UR+r3zObgI1k5z/2FRavY KoyTLnhWl+NiQgO37PmbmiOtkGQ990IJoXa8C7rqp7PM+Ge4oi0OUgNWVPvv9axcToQb d+NpntpujGzN28NQvuYPjVNGew4DZPdJqAPMZ0+enQ/lI9xTiZtml7CM+aGyYooz/UUc 922mjxMtjEzzv9i/0j+nIKYc3+Oc87HpAhFx+4dnkzGIA8ZCl6Fbe12m8gV1YTzQluEf a+c55vnjsKs49o5u7o8FcH2nph9hwu7PyJDSmaPXG6/QN0/TvbG9r83I5+latM3fJ8k6 HGQQ== X-Gm-Message-State: AGi0PuazD7RQoxPb5Nhay4nQh+QMFer3PdKKmzrtVe1pvsqjbKolhbQr PqMdhWxjI9ReL2Ug8LWhtCg= X-Google-Smtp-Source: APiQypLCzLi28uZ9bahmO7Z3PVZGhnTzNbaVcCbmHy+m/fBgPgeXw3iorTSbzaO9gBIS13y1kYck6w== X-Received: by 2002:a7b:c145:: with SMTP id z5mr3097856wmi.55.1585729907100; Wed, 01 Apr 2020 01:31:47 -0700 (PDT) Received: from localhost (ip-37-188-180-223.eurotel.cz. [37.188.180.223]) by smtp.gmail.com with ESMTPSA id j188sm1722851wmj.36.2020.04.01.01.31.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Apr 2020 01:31:46 -0700 (PDT) Date: Wed, 1 Apr 2020 10:31:45 +0200 From: Michal Hocko To: "Huang, Ying" Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Hugh Dickins , Rik van Riel Subject: Re: [PATCH] mm, trivial: Simplify swap related code in try_to_unmap_one() Message-ID: <20200401083145.GF22681@dhcp22.suse.cz> References: <20200331084613.1258555-1-ying.huang@intel.com> <20200331094108.GF30449@dhcp22.suse.cz> <87tv24j9hq.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87tv24j9hq.fsf@yhuang-dev.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 Wed 01-04-20 09:11:13, Huang, Ying wrote: [...] > Then what is the check !PageSwapBacked() && PageSwapCache() for? To > prevent someone to change the definition of PageSwapCache() in the > future to break this? Yes this is my understading. It is essentially an assert that enforces the assumption about swap cache vs. swap backed being coupled. -- Michal Hocko SUSE Labs