From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 7BF0D6B0012 for ; Wed, 11 May 2011 05:33:37 -0400 (EDT) Received: by iyh42 with SMTP id 42so256664iyh.14 for ; Wed, 11 May 2011 02:33:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1305073386-4810-3-git-send-email-john.stultz@linaro.org> References: <1305073386-4810-1-git-send-email-john.stultz@linaro.org> <1305073386-4810-3-git-send-email-john.stultz@linaro.org> Date: Wed, 11 May 2011 17:33:34 +0800 Message-ID: Subject: Re: [PATCH 2/3] printk: Add %ptc to safely print a task's comm From: =?UTF-8?Q?Am=C3=A9rico_Wang?= Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: John Stultz Cc: LKML , Ted Ts'o , KOSAKI Motohiro , David Rientjes , Dave Hansen , Andrew Morton , linux-mm@kvack.org On Wed, May 11, 2011 at 8:23 AM, John Stultz wrote: > Acessing task->comm requires proper locking. However in the past > access to current->comm could be done without locking. This > is no longer the case, so all comm access needs to be done > while holding the comm_lock. > > In my attempt to clean up unprotected comm access, I've noticed > most comm access is done for printk output. To simpify correct > locking in these cases, I've introduced a new %ptc format, > which will safely print the corresponding task's comm. > > Example use: > printk("%ptc: unaligned epc - sending SIGBUS.\n", current); > Why do you hide current->comm behide printk? How is this better than printk("%s: ....", task_comm(current)) ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org