Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754464AbbFBKb4 (ORCPT ); Tue, 2 Jun 2015 06:31:56 -0400 Received: from cantor2.suse.de ([195.135.220.15]:41063 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752948AbbFBKbq (ORCPT ); Tue, 2 Jun 2015 06:31:46 -0400 Date: Tue, 2 Jun 2015 12:31:44 +0200 From: Jiri Bohac To: John Stultz Cc: lkml , Prarit Bhargava , Daniel Bristot de Oliveira , Richard Cochran , Jan Kara , Thomas Gleixner , Ingo Molnar , Shuah Khan Subject: Re: [RFC][PATCH 3/4] ntp: Use printk_deferred in leapsecond path Message-ID: <20150602103144.GB18714@midget.suse.cz> References: <1432931068-4980-1-git-send-email-john.stultz@linaro.org> <1432931068-4980-4-git-send-email-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1432931068-4980-4-git-send-email-john.stultz@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1141 Lines: 34 Hi, On Fri, May 29, 2015 at 01:24:27PM -0700, John Stultz wrote: > Looking over the leapsecond code, I noticed the printk messages > reporting the leapsecond insertion in the second_overflow path > were not using the printk_deferred method. This was surprising > since the printk_deferred method was added in part to avoid > printk-ing while holding the timekeeping locks. > > See 6d9bcb621b0b (timekeeping: use printk_deferred when holding > timekeeping seqlock) for further rational. > > I can only guess that this omission was a git add -p oversight. second_overflow() is called from accumulate_nsecs_to_secs(). accumulate_nsecs_to_secs() is called from update_wall_time() - once directly - once via logarithmic_accumulation() Both calls are before write_seqcount_begin(&tk_core.seq). So it looks safe to use printk there. Regards, -- Jiri Bohac SUSE Labs, SUSE CZ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/