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[209.85.167.54]) by smtp.gmail.com with ESMTPSA id 201sm4307293ljf.75.2020.09.14.17.42.34 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Sep 2020 17:42:35 -0700 (PDT) Received: by mail-lf1-f54.google.com with SMTP id x77so1275746lfa.0 for ; Mon, 14 Sep 2020 17:42:34 -0700 (PDT) X-Received: by 2002:ac2:5594:: with SMTP id v20mr5487901lfg.344.1600130554524; Mon, 14 Sep 2020 17:42:34 -0700 (PDT) MIME-Version: 1.0 References: <8bb582d2-2841-94eb-8862-91d1225d5ebc@MichaelLarabel.com> <0cbc959e-1b8d-8d7e-1dc6-672cf5b3899a@MichaelLarabel.com> <0daf6ae6-422c-dd46-f85a-e83f6e1d1113@MichaelLarabel.com> <20200912143704.GB6583@casper.infradead.org> <658ae026-32d9-0a25-5a59-9c510d6898d5@MichaelLarabel.com> In-Reply-To: From: Linus Torvalds Date: Mon, 14 Sep 2020 17:42:18 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Kernel Benchmarking To: Matthieu Baerts Cc: Michael Larabel , Matthew Wilcox , Amir Goldstein , "Ted Ts'o" , Andreas Dilger , Ext4 Developers List , Jan Kara , linux-fsdevel Content-Type: text/plain; charset="UTF-8" Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Sep 14, 2020 at 1:53 PM Linus Torvalds wrote: > > One way I can see that happening (with the fair page locking) is to do > something like this Note that the "lock_page()" cases in that deadlock example sequence of mine is not necessarily at all an explicit lock_page(). It is more likely to be something that indirectly causes it - like a user access that faults in the page and causes lock_page() as part of that. Linus