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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 CB3CFC433E7 for ; Thu, 8 Oct 2020 17:09:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BA5C221FD for ; Thu, 8 Oct 2020 17:09:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602176968; bh=KuHL8U4S5LCxEklC4MrYUMrJcUruXAHx5+PTKvaC0Bc=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=G7/tHLCiUslTlfgUDb7Ud0sCF0l29vYH1CeNDYR/uGqHak8gDulkeeISCTWSjoyvB nFi8w+V+XQMazJdziWpEZtlwirc7a9PAMrkcJvUEM8gazI9JeaCsRxVYdDgCDMOMSP flZjt5eE9esaHRSZ4nDJp+eEjs1/mr+VJn439EZE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730636AbgJHRJ1 (ORCPT ); Thu, 8 Oct 2020 13:09:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730147AbgJHRJ1 (ORCPT ); Thu, 8 Oct 2020 13:09:27 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF451C061755 for ; Thu, 8 Oct 2020 10:09:26 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id y16so5404249ljk.1 for ; Thu, 08 Oct 2020 10:09:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Z5wcuDA1gh/3Ps6l+NWlPcHbmyW5YaIQwLSEAvKTv+g=; b=cZHvUXj5G6+H19Nj4m528LVZtsoSSR8DXg8s8jyXKZNl8yYlcGAb2i3EBmVhdsS3AF W3RfTehbw6eYlGzzLmiYFkaUZwBpmdmMlDJneXc80kfm7LkKDSW9OkSK0jUhE0zjXx/x +Nat7/Qr8ncJLNBYgRySy7Jc9Y8kWw+L70eL0= 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=Z5wcuDA1gh/3Ps6l+NWlPcHbmyW5YaIQwLSEAvKTv+g=; b=nFjOWTeJcJG2C3pYMy0o8C9ZZ3TBNCcFTsTZS7dfJJf9FueooC7igogJCN3HEl5HnL 7/UVSMgQZpiq4pAuYLMXfZiYFn4DZhB43oBa/t1Y/fS9GR2Vz98tSOjs8nyddZ9BVf+2 Ld4e8xYE1vEWDPChfCp5L2GrUrJuYlcopTVxOCTQBPz+9OGVHg33zX/SvF42f8nJuJbf xmOKFwWBCvfgg8Uh9IZdnPHBCKwWt0JvEK0U+wDU9yxxKgH5Hkpt9lckJfUYEmivMIzA qswOBdWDbUFfFBzJR7goytt4hdg/XvD3ctyZl77dKXJsSa0vhJton2VH8WQ79xVGG6CC Qdog== X-Gm-Message-State: AOAM533ezzHf1NVMY+yS9meC/offdh+PO1fedeIflkXDaNgwnww209uC 5SMOzg+C+mY81nrLJAZ+1jnzrIIAritWLQ== X-Google-Smtp-Source: ABdhPJx4BRhe268+XP5dIziWb/v0DuUuwvZjGGE2arV8Q5I1I3CR73LdH233rjCbvQHaqw1Nfj/+kA== X-Received: by 2002:a2e:97d6:: with SMTP id m22mr3465078ljj.328.1602176964421; Thu, 08 Oct 2020 10:09:24 -0700 (PDT) Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com. [209.85.208.182]) by smtp.gmail.com with ESMTPSA id j17sm1051449ljg.82.2020.10.08.10.09.22 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Oct 2020 10:09:23 -0700 (PDT) Received: by mail-lj1-f182.google.com with SMTP id 133so6577516ljj.0 for ; Thu, 08 Oct 2020 10:09:22 -0700 (PDT) X-Received: by 2002:a2e:2202:: with SMTP id i2mr3411487lji.70.1602176962536; Thu, 08 Oct 2020 10:09:22 -0700 (PDT) MIME-Version: 1.0 References: <20201008092541.398079-1-aneesh.kumar@linux.ibm.com> In-Reply-To: <20201008092541.398079-1-aneesh.kumar@linux.ibm.com> From: Linus Torvalds Date: Thu, 8 Oct 2020 10:09:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm: Avoid using set_pte_at when updating a present pte To: "Aneesh Kumar K.V" , Leon Romanovsky Cc: linuxppc-dev , Michael Ellerman , Nick Piggin , Peter Xu , Jason Gunthorpe , John Hubbard , Linux-MM , Linux Kernel Mailing List , Andrew Morton , Jan Kara , Michal Hocko , Kirill Shutemov , Hugh Dickins Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ahh, and I should learn to read all my emails before replying to some of them.. On Thu, Oct 8, 2020 at 2:26 AM Aneesh Kumar K.V wrote: > > This avoids the below warning > [..] > WARNING: CPU: 0 PID: 30613 at arch/powerpc/mm/pgtable.c:185 set_pte_at+0x2a8/0x3a0 arch/powerpc/mm/pgtable.c:185 .. and I assume this is what triggered the other patch too. Yes, with the ppc warning, we need to do _something_ about this, and at that point I think the "something" is to just avoid the pte wrpritect trick. Linus