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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EDB0EC3E8C5 for ; Fri, 27 Nov 2020 16:45:17 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1583E20657 for ; Fri, 27 Nov 2020 16:45:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="udwA9p34" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1583E20657 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (unknown [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CjL8V4MSzzDrPF for ; Sat, 28 Nov 2020 03:45:14 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2a00:1450:4864:20::144; helo=mail-lf1-x144.google.com; envelope-from=urezki@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=udwA9p34; dkim-atps=neutral Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4CjL4R5f0RzDrfl for ; Sat, 28 Nov 2020 03:41:38 +1100 (AEDT) Received: by mail-lf1-x144.google.com with SMTP id a9so7873582lfh.2 for ; Fri, 27 Nov 2020 08:41:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=rgkrb035jm9NJnipoFNp6J644nVoW0SJU1WZzjzA+oA=; b=udwA9p34XKAzVdUynfyA3sUQIHdQlG/KghvzCRzcKIP+V6Ez0oaYWmUIVE5rTY6I/e CW4TCmiSwaTCiKDJXkn7LgN9+fjAGq6lrtbJ42gd4XLIk+N7/71H4pKuqh3TBy79TYvM 1kOi7hd6b/9KCo6JhpWznw7poOjXY8a3z00zANtR8Fr+yhOvY1eHPYt8clzfeCOb4inW 7HkL1Lx0rdIJN4uiRZH4AjcAap7qCC/+qWIn7hgSHtQ4+Vw8yB773T7eD9kntRacbjET xTJA12M/jwG7M8J0tS6CXBOGuRaO7dRGqyaBJ9KUdV7oMYH39dT18YhqJomNnBOHMnUk BAjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=rgkrb035jm9NJnipoFNp6J644nVoW0SJU1WZzjzA+oA=; b=jfyQTCXGSDqepeiO6Z/OZWSHEdWULYIhyMu1S72+kDKV8Cm4F0opJqETbIni8z4LSx z9EpQ5dxKmQo0blWkLAAWbTz+gZ5G/kHRZYcMlQwxPtRcj/DwvwjFQffcJjIytsSG4nW xdzLR4sRIH6McywfQkFy8UHIS+97IapHervSgcf/9i5QiNVDUB4AxPFXAAMZjVqsKJ7D /j/UMWKwaF/1m5dvJbBpjp1JAbxGQlsviy+zskNN2c0nbswLq0Hb0gLXMrYkLo2vQaRw 1l8mRqAqy/PPY9E7m65Nk0b/zKDl1CBEgiYanJ715WlWLQzxZbm+lhBCyucJb/OvHlTV qSPA== X-Gm-Message-State: AOAM5327TaFcOp/3cLm2M6QgdeIyMqCyLTXSQGCh7BYo9n0SuSrOViNf 25XqrmFmMJ+G/E1iaJHZVnw= X-Google-Smtp-Source: ABdhPJzRxFJh5kMK+j5klpIKR50QifbYdGTWz6/104SUlMn5MLebth9HJ3j5Q4yoeCN71TH/Be22kw== X-Received: by 2002:a19:e46:: with SMTP id 67mr3959180lfo.108.1606495291010; Fri, 27 Nov 2020 08:41:31 -0800 (PST) Received: from pc638.lan (h5ef52e3d.seluork.dyn.perspektivbredband.net. [94.245.46.61]) by smtp.gmail.com with ESMTPSA id 4sm1012291ljf.96.2020.11.27.08.41.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Nov 2020 08:41:30 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 27 Nov 2020 17:41:28 +0100 To: Daniel Axtens Subject: Re: powerpc 5.10-rcN boot failures with RCU_SCALE_TEST=m Message-ID: <20201127164128.GA47008@pc638.lan> References: <87eekfh80a.fsf@dja-thinkpad.axtens.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87eekfh80a.fsf@dja-thinkpad.axtens.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: rcu@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" > Hi all, > > I'm having some difficulty tracking down a bug. > > Some configurations of the powerpc kernel since somewhere in the 5.10 > merge window fail to boot on some ppc64 systems. They hang while trying > to bring up SMP. It seems to depend on the RCU_SCALE/PERF_TEST option. > (It was renamed in the 5.10 merge window.) > > I can reproduce it as follows with qemu tcg: > > make -j64 pseries_le_defconfig > scripts/config -m RCU_SCALE_TEST > scripts/config -m RCU_PERF_TEST > make -j 64 vmlinux CC="ccache gcc" > > qemu-system-ppc64 -cpu power9 -M pseries -m 1G -nographic -vga none -smp 4 -kernel vmlinux > > ... > [ 0.036284][ T0] Mount-cache hash table entries: 8192 (order: 0, 65536 bytes, linear) > [ 0.036481][ T0] Mountpoint-cache hash table entries: 8192 (order: 0, 65536 bytes, linear) > [ 0.148168][ T1] POWER9 performance monitor hardware support registered > [ 0.151118][ T1] rcu: Hierarchical SRCU implementation. > [ 0.186660][ T1] smp: Bringing up secondary CPUs ... > > I am not sure if that is helpful but i checked it on my x86_64 system using the cross compiled for powerpc Linux kernel: urezki@pc638:~/data/coding/linux-rcu.git$ powerpc64-linux-gnu-gcc --version powerpc64-linux-gnu-gcc (Debian 8.3.0-2) 8.3.0 Copyright (C) 2018 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. urezki@pc638:~/data/coding/linux-rcu.git$ with ARCH=powerpc make -j64 pseries_defconfig configuration. I used the 5.10.0-rc1 kernel. urezki@pc638:~/data/coding/linux-rcu.git$ qemu-system-ppc64 --version QEMU emulator version 3.1.0 (Debian 1:3.1+dfsg-8+deb10u8) Copyright (c) 2003-2018 Fabrice Bellard and the QEMU Project developers urezki@pc638:~/data/coding/linux-rcu.git$ On my setup i can run the kernel with and without the modules which are in question. So qemu-system-ppc64 -cpu power9 -M pseries -m 1G -nographic -vga none -smp 4 -kernel ./vmlinux works for both cases, with RCU_SCALE and without. Just in case, maybe this information can be useful also. -- Vlad Rezki