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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 BBB29C433ED for ; Sun, 18 Apr 2021 13:54:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 B7A4061278 for ; Sun, 18 Apr 2021 13:54:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7A4061278 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FNWf85CSgz3c1G for ; Sun, 18 Apr 2021 23:54:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=EsUR0jmm; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=2401:3900:2:1::2; helo=ozlabs.org; envelope-from=michael@ozlabs.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=EsUR0jmm; dkim-atps=neutral Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FNWdj64wMz300J for ; Sun, 18 Apr 2021 23:54:17 +1000 (AEST) Received: by ozlabs.org (Postfix, from userid 1034) id 4FNWdh4VCPz9vFw; Sun, 18 Apr 2021 23:54:16 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1618754056; bh=kfsM+rTNtSsxB5i27Fxr65yD7ye26wCG4rKkWJ3z9yo=; h=From:To:Subject:Date:From; b=EsUR0jmmR+xmr4Ge56pi5pvaGwFx5nP7OxFkT9jc3s7msV9DkQrm8Pqfy6rEIT9C8 qOg2kaT8VeTy/vgaYauPdkJe90ydQSWYsneFo0ZykZRmU/vPtG6v5I5IA3PQW+RRFj ZTu7H+yNr6wBt8CJN3BBB33tDyKeBEyV5BIDYr98s0cctkqbp9C+HoHWyzCH240lv1 uSBbiBzfBLiBpJjvCoZrJAZjbFv0j8Qu4ZQdn7tVLKCNiLMwnMRc3g/kdZxiEDnQxX SjKkH+KrTh9AnFJtESFcZmv5/KKdYOENXdCSm+EvrJRWBzFmNyBazGtScX9RA1LESB TVe29azDhbS+w== From: Michael Ellerman To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/pseries: Stop calling printk in rtas_stop_self() Date: Sun, 18 Apr 2021 23:54:13 +1000 Message-Id: <20210418135413.1204031-1-mpe@ellerman.id.au> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" RCU complains about us calling printk() from an offline CPU: ============================= WARNING: suspicious RCU usage 5.12.0-rc7-02874-g7cf90e481cb8 #1 Not tainted ----------------------------- kernel/locking/lockdep.c:3568 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 2, debug_locks = 1 no locks held by swapper/0/0. stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7-02874-g7cf90e481cb8 #1 Call Trace: dump_stack+0xec/0x144 (unreliable) lockdep_rcu_suspicious+0x124/0x144 __lock_acquire+0x1098/0x28b0 lock_acquire+0x128/0x600 _raw_spin_lock_irqsave+0x6c/0xc0 down_trylock+0x2c/0x70 __down_trylock_console_sem+0x60/0x140 vprintk_emit+0x1a8/0x4b0 vprintk_func+0xcc/0x200 printk+0x40/0x54 pseries_cpu_offline_self+0xc0/0x120 arch_cpu_idle_dead+0x54/0x70 do_idle+0x174/0x4a0 cpu_startup_entry+0x38/0x40 rest_init+0x268/0x388 start_kernel+0x748/0x790 start_here_common+0x1c/0x614 Which happens because by the time we get to rtas_stop_self() we are already offline. In addition the message can be spammy, and is not that helpful for users, so remove it. Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index ec478f8a98ff..48d9dfc3fad1 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -47,9 +47,6 @@ static void rtas_stop_self(void) BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE); - printk("cpu %u (hwid %u) Ready to die...\n", - smp_processor_id(), hard_smp_processor_id()); - rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL); panic("Alas, I survived.\n"); -- 2.25.1