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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87C67C433F5 for ; Mon, 9 May 2022 13:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235293AbiEINOq (ORCPT ); Mon, 9 May 2022 09:14:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235184AbiEINOn (ORCPT ); Mon, 9 May 2022 09:14:43 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B97322519; Mon, 9 May 2022 06:10:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=c6E44QfcLWCPcpfVVn8DZm/tazb9qDNjecxU8jgjjwM=; b=JQ1X+XDjDPRoAxPLkbe9tWes8w l11iC7oa/HVnyRK3qB7UvK9JEgQqPIREqD5654T0lMLes3kGheOm/R45s0nxu4hyBPxmCTVnzlJkN ZvlwDaZFuWVIh4IaLUzoP+QdJvpm215SH2+0rVomODoRdVpIAavgxOQl3rDnkTMN+fyPnfNOV7B7S PwRkKHJor0sF94EKnip9+x+OMSUvYBWlrOB2NiCodRGVM8ztswBp00gdyDLuMLY0TLuRV/nOMh+Z7 dku4FKzrs/p9E3LkAgwz4nFi/oHL/EcQWXaMAdDUro5POIL0/IvuDCL2llWo8K6mm9F1PYJhGhMV8 hibQS8tw==; Received: from [177.183.162.244] (helo=[192.168.0.5]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1no39b-0005V6-KV; Mon, 09 May 2022 15:10:24 +0200 Message-ID: <65f24bc5-2211-0139-ee12-b2608e81ceb1@igalia.com> Date: Mon, 9 May 2022 10:09:21 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH 09/30] coresight: cpu-debug: Replace mutex with mutex_trylock on panic notifier Content-Language: en-US To: Suzuki K Poulose , akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, coresight@lists.linaro.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, Leo Yan , Mathieu Poirier , Mike Leach References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-10-gpiccoli@igalia.com> <3cafe4fd-8a0b-2633-44a3-2995abd6c38c@arm.com> From: "Guilherme G. Piccoli" In-Reply-To: <3cafe4fd-8a0b-2633-44a3-2995abd6c38c@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 28/04/2022 05:11, Suzuki K Poulose wrote: > Hi Guilherme, > > On 27/04/2022 23:49, Guilherme G. Piccoli wrote: >> The panic notifier infrastructure executes registered callbacks when >> a panic event happens - such callbacks are executed in atomic context, >> with interrupts and preemption disabled in the running CPU and all other >> CPUs disabled. That said, mutexes in such context are not a good idea. >> >> This patch replaces a regular mutex with a mutex_trylock safer approach; >> given the nature of the mutex used in the driver, it should be pretty >> uncommon being unable to acquire such mutex in the panic path, hence >> no functional change should be observed (and if it is, that would be >> likely a deadlock with the regular mutex). >> >> Fixes: 2227b7c74634 ("coresight: add support for CPU debug module") >> Cc: Leo Yan >> Cc: Mathieu Poirier >> Cc: Mike Leach >> Cc: Suzuki K Poulose >> Signed-off-by: Guilherme G. Piccoli > > How would you like to proceed with queuing this ? I am happy > either way. In case you plan to push this as part of this > series (I don't see any potential conflicts) : > > Reviewed-by: Suzuki K Poulose Hi Suzuki, some other maintainers are taking the patches to their next branches for example. I'm working on V2, and I guess in the end would be nice to reduce the size of the series a bit. So, do you think you could pick this one for your coresight/next branch (or even for rc cycle, your call - this is really a fix)? This way, I won't re-submit this one in V2, since it's gonna be merged already in your branch. Thanks in advance, Guilherme