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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 BF75AC433E7 for ; Tue, 21 Jul 2020 11:44:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A13E2073A for ; Tue, 21 Jul 2020 11:44:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="D+gl//id" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729316AbgGULoK (ORCPT ); Tue, 21 Jul 2020 07:44:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728560AbgGULoJ (ORCPT ); Tue, 21 Jul 2020 07:44:09 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92FFDC061794 for ; Tue, 21 Jul 2020 04:44:09 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id 11so9404777qkn.2 for ; Tue, 21 Jul 2020 04:44:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:cc:in-reply-to:to; bh=JkLTqUSBRUuKpZ5ZCYN1xKhQ405tLy+Ys8G86xno/fg=; b=D+gl//id0PU4FSCM9quXGNwKUbe/L8HeI5BWlFcUccDBfjUhNceRarNqpFqMM5itIq wx9I/Lor5UySH47NQ/dU1IuyhKt2hBLq+hem0iPJ6sjIzVwWpF0quqVddFRPKkrMHazK HPvASbxbFHzIXL1i6l0g6Ib7YgpkJAoh67qVbBmM+QuIRFZW6N3CktMBwbA3Nw5fAhkp c8LuE2Kk3cWgBzq69mbnFF+c4rtuHCiBkJuU+WLELgrsB0WuvxVOGtub3UtJcvUV7KuN qUrgVCMNE2Fr4/G5tAfBiFGwanFQNC0SAjj33TOPY0oUTCqhuV3IpmtuluiL5tgCg3n9 iACA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:cc:in-reply-to:to; bh=JkLTqUSBRUuKpZ5ZCYN1xKhQ405tLy+Ys8G86xno/fg=; b=H3tXZ2ZbNXHa4Q4x8qFuE3PF+5a5ue0Owfcy3TAL3xiIPEPE4anLc9YzFUIHgxNjmu sf+B+4fYQJpcWQsYV8pq1Ha1hkS+1mSvO4v+T7tUgpGQG4rCd+F9dXr1K8bmpCrCENpk /EKcNI61bW2n+7hEYO2iw6Yxh+RXGhmFlNGj8s29aEdKBU27Oa4G3Tm6hCMB9ZWdxsHS lenJjljIWQwYwgxBf81ZxgX/Cv6yl4MLnqQMZUEOqSk72QrPu1hDIj77cYucBJDwrAGw Fru29fczBeKCXSd6F3UQ1oUoN2V9YAsonOzfzazxD5bh+xstzUsoB6xwL5iU95tl7Q8f WUSA== X-Gm-Message-State: AOAM533+4yyvpnt1nqLiHb2jNu+bIYWomZSwBdhEO/si69Z1mjL4IVUK yG7dvFdqvONgNvC4js53zXQxVg== X-Google-Smtp-Source: ABdhPJz+m91AzTJAYvWj/hvlGxZ7YttZHhqDuSVhHEXQuTiIzsbS6dDFY4kAfz8rqFvZYSocPOYRSw== X-Received: by 2002:a37:7242:: with SMTP id n63mr26655272qkc.143.1595331848849; Tue, 21 Jul 2020 04:44:08 -0700 (PDT) Received: from [192.168.1.183] (pool-71-184-117-43.bstnma.fios.verizon.net. [71.184.117.43]) by smtp.gmail.com with ESMTPSA id o18sm2009257qkk.91.2020.07.21.04.44.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Jul 2020 04:44:08 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Qian Cai Mime-Version: 1.0 (1.0) Subject: Re: [RFC PATCH] mm: silence soft lockups from unlock_page Date: Tue, 21 Jul 2020 07:44:07 -0400 Message-Id: <664A07B6-DBCD-4520-84F1-241A4E7A339F@lca.pw> References: <20200721112529.GJ4061@dhcp22.suse.cz> Cc: linux-mm@kvack.org, LKML , Andrew Morton , Linus Torvalds , Tim Chen In-Reply-To: <20200721112529.GJ4061@dhcp22.suse.cz> To: Michal Hocko X-Mailer: iPhone Mail (17F80) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Jul 21, 2020, at 7:25 AM, Michal Hocko wrote: >=20 > Are these really important? I believe I can dig that out from the bug > report but I didn't really consider that important enough. Please dig them out. We have also been running those things on =E2=80=9Clarg= e=E2=80=9D powerpc as well and never saw such soft-lockups. Those details ma= y give us some clues about the actual problem. Once we understand the proble= m better, we may judge if this =E2=80=9Chack=E2=80=9D is really worth it.=