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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 C1A62C433C1 for ; Tue, 23 Mar 2021 17:59:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 344DA6191D for ; Tue, 23 Mar 2021 17:59:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 344DA6191D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4A2586B0279; Tue, 23 Mar 2021 13:58:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 42B276B027D; Tue, 23 Mar 2021 13:58:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27DF36B027E; Tue, 23 Mar 2021 13:58:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0038.hostedemail.com [216.40.44.38]) by kanga.kvack.org (Postfix) with ESMTP id 0F6636B0279 for ; Tue, 23 Mar 2021 13:58:59 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id C924912DC for ; Tue, 23 Mar 2021 17:58:58 +0000 (UTC) X-FDA: 77951899956.25.BE1796F Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) by imf20.hostedemail.com (Postfix) with ESMTP id B962CF0 for ; Tue, 23 Mar 2021 17:58:57 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id jy13so28548605ejc.2 for ; Tue, 23 Mar 2021 10:58:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Hcso62Cwuwa8e074vVIkc2Y/lBuLyaEVj57l1knVuck=; b=kSu1qZu/6KIwGQOL78KtzGiGXVngtGo32objrxmPa99ZKbN+0ks597f3rZiIdISZoy Y/y50+y3Vw/p1yCApyQA8nHVe6Z7nILZe7FJcfH4XGGe+uVXdfUZkt0RMBIT9jWktrmN ewhLtOHhervZs5hP63XmYCxfEXWzt8Io9Xedy//7w4WIzb9KvFAwKyzTpeKIztPloMJy 03Rjxw825hOSiA4ICwYNIwPJMZehDQjA/lFRjOMfUQuPn3NljnEYO0tqg5PeqBW585Bw 2lb+QFVY5v0/pBBhDnV/ykctWhKKbyFwsW01o/a+4EeVQSz+Z9mc9wN9N/CW7CbXD2+C DFcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Hcso62Cwuwa8e074vVIkc2Y/lBuLyaEVj57l1knVuck=; b=h7hXwHeHXd8HX/bFZOvsKoinStlddlBrwNq93EmhPtN+jCD4WHahziTuiAGiTdYBjj 8PbcV6PLxeww9/URp3fn0GhO0A2RrsZgV/rC9Ae2SWb9kyNtjNN/gztQp9OfwJinazpx giwhN7yFq7NSkwitABMTjWUW9socdtuqpZKDjWlU1BbdxncQktENHI11aSXN9v5ss6PP 9HXCPRoD8b1zHjvtlmC4JyE8pTRhA911ljpOrYBFVphFWw8fvnex2j+telHrkjW7VOiK t6BU7iYdJ70YyiSkYMbR0do0PWkJx6Y8BBTuiqUmtYtKDX/ODOVn6CuWpgpN144/N5Ip p97g== X-Gm-Message-State: AOAM5310GXGtJYVYuh6+Ycq+Dd3IxBja3LYwS23VP+9jgRGpEU77GiqQ M68Ce60TML+/CDMa+bNyiZO5QtY7lSlamem4wq4= X-Google-Smtp-Source: ABdhPJyChTK0RiirCrD6IZ+vQGYCcPU/l3grbGZmk73eHVPYuK/g8Jb28ZnzKnPLt6CPQaewml8UzL692IW58C2UmVM= X-Received: by 2002:a17:906:789:: with SMTP id l9mr6079486ejc.161.1616522337166; Tue, 23 Mar 2021 10:58:57 -0700 (PDT) MIME-Version: 1.0 References: <20210323135405.65059-1-linmiaohe@huawei.com> <20210323135405.65059-2-linmiaohe@huawei.com> In-Reply-To: <20210323135405.65059-2-linmiaohe@huawei.com> From: Yang Shi Date: Tue, 23 Mar 2021 10:58:45 -0700 Message-ID: Subject: Re: [PATCH v2 1/5] mm/migrate.c: remove unnecessary VM_BUG_ON_PAGE on putback_movable_page() To: Miaohe Lin Cc: Andrew Morton , Jerome Glisse , Rafael Aquini , David Hildenbrand , Alistair Popple , Linux Kernel Mailing List , Linux MM Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: ads8tff1zrxti513ecbjwwoohoxt31yz X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: B962CF0 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf20; identity=mailfrom; envelope-from=""; helo=mail-ej1-f46.google.com; client-ip=209.85.218.46 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616522337-215892 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 Tue, Mar 23, 2021 at 6:54 AM Miaohe Lin wrote: > > The !PageLocked() check is implicitly done in PageMovable(). Remove this > explicit one. TBH, I'm a little bit reluctant to have this kind change. If "locked" check is necessary we'd better make it explicit otherwise just remove it. And why not just remove all the 3 VM_BUG_ON_PAGE since putback_movable_page() is just called by putback_movable_pages() and we know the page is locked and both PageMovable and PageIsolated is checked right before calling putback_movable_page(). And you also could make putback_movable_page() static. > Signed-off-by: Miaohe Lin > --- > mm/migrate.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 47df0df8f21a..facec65c7374 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -145,7 +145,6 @@ void putback_movable_page(struct page *page) > { > struct address_space *mapping; > > - VM_BUG_ON_PAGE(!PageLocked(page), page); > VM_BUG_ON_PAGE(!PageMovable(page), page); > VM_BUG_ON_PAGE(!PageIsolated(page), page); > > -- > 2.19.1 >