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=-5.2 required=3.0 tests=BAYES_00, BUG6152_INVALID_DATE_TZ_ABSURD,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,INVALID_DATE_TZ_ABSURD,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8BFB3C433E0 for ; Wed, 10 Feb 2021 18:07:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E48B6023B for ; Wed, 10 Feb 2021 18:07:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233795AbhBJSHT (ORCPT ); Wed, 10 Feb 2021 13:07:19 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:33286 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231596AbhBJSAt (ORCPT ); Wed, 10 Feb 2021 13:00:49 -0500 From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1612980007; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VVaz0IfL2E09co0Q9gha9+MbY3zsBtFKkJzzyGGZ4ck=; b=lnXI4mqtiZKe/PSZaFirN123iMcJeSpQSmS1r1VGQkTwJK/fbz82IxKWOc5N909VzZM4m0 Gtz/PXavtRcv4K8eiEjOePEoXo+M5tLdSOMrL8rzeTAaUGgJniGiwPTnE8DKhd6fOP07qD vZvqILfxKYwZOcU4EiSybtrwrwUKhK77V0DZx5ce/hWQN3Yscg3R6cOtDgBqhavuKe/jx8 P2p1h9UHUOI9QfPpPqKTPlYY2gYRmhXf0tw/nG9i0FSAEbWFhecZLQXbV6QeO83OvX4GNy v5qTDJ6cXOx3NlXFVXw57t8mgGb4vdw5vnlR8wd0rc50sGFyVHVvfnbC6BLBHQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1612980007; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VVaz0IfL2E09co0Q9gha9+MbY3zsBtFKkJzzyGGZ4ck=; b=kQcVkkEjzNJpDvt/R9ad5yAjImmeSy0oKKM+gUWAWnsbln6aWlAnTas+pku3swqwKJZjsY SZrQWzaLdkW6vMCA== To: Sergey Senozhatsky Cc: Petr Mladek , Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , linux-kernel@vger.kernel.org, "J. Avila" , Oliver Sang Subject: Re: [PATCH] printk: avoid prb_first_valid_seq() where possible In-Reply-To: <87ft26oqya.fsf@jogness.linutronix.de> References: <20210205141728.18117-1-john.ogness@linutronix.de> <87ft26oqya.fsf@jogness.linutronix.de> Date: Wed, 10 Feb 2021 19:06:07 +0106 Message-ID: <877dnf4xco.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-02-08, Sergey Senozhatsky wrote: >> Can we please also ask the kernel test robot to test this patch? Oliver Sang from LKP was able to verify that the RCU stall problem is not seen anymore on their side. See his response below. Thanks Oliver! John Ogness On 2021-02-10, Oliver Sang wrote: > On Mon, Feb 08, 2021 at 10:35:27AM +0106, John Ogness wrote: >> Hello LKP Project, >> >> Thank you for your valuable and excellent work! >> >> You recently detected a problem: >> >> https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/STZF3OODVA5KOG447JR2AJJXREWIPRXD/ >> >> We have posted a patch to fix the issue: >> >> https://lkml.kernel.org/r/20210205141728.18117-1-john.ogness@linutronix.de > > Hi John Ogness, > > by applying the patch upon below commit: > commit: b031a684bfd01d633c79d281bd0cf11c2f834ada ("printk: remove logbuf_lock writer-protection of ringbuffer") > > we didn't reproduce the previous INFO:rcu_tasks_detected_stalls_on_tasks > issue in 30 runs: > > b031a684bfd01d63: ("printk: remove logbuf_lock writer-protection of ringbuffer") > 7e926a042bfad8b7: ("printk: avoid prb_first_valid_seq() where possible") > > b031a684bfd01d63 7e926a042bfad8b7334b4677d3 > ---------------- -------------------------- > fail:runs %reproduction fail:runs > | | | > 10:21 -48% :30 dmesg.INFO:rcu_tasks_detected_stalls_on_tasks > 19:21 -90% :30 last_state.is_incomplete_run > 1:21 -5% :30 last_state.post_run > > >> >> Using a local lkp installation I can verify the problem is fixed. But we >> would like to know if there possibilities to verify fixes using the LKP >> test robot? Or is there any way to check that the test robot sees the >> problem is fixed? >> >> Thanks. >> >> John Ogness