Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752779AbdGFD7B (ORCPT ); Wed, 5 Jul 2017 23:59:01 -0400 Received: from mail-pg0-f45.google.com ([74.125.83.45]:35901 "EHLO mail-pg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbdGFD67 (ORCPT ); Wed, 5 Jul 2017 23:58:59 -0400 Date: Thu, 6 Jul 2017 12:58:55 +0900 From: Stafford Horne To: John Stultz Cc: LKML , Thomas Gleixner , Stephen Boyd Subject: Re: [PATCH] timekeeping: Use proper timekeeper for debug code Message-ID: <20170706035855.GA2511@lianli.shorne-pla.net> References: <20170628132135.13622-1-shorne@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1164 Lines: 32 Hi tglx, Sorry, to bother you, I thought maybe this you missed this one? Let me know if you want a resend. -Stafford On Wed, Jun 28, 2017 at 10:39:21AM -0700, John Stultz wrote: > On Wed, Jun 28, 2017 at 6:21 AM, Stafford Horne wrote: > > When CONFIG_DEBUG_TIMEKEEPING is enabled the timekeeping_check_update() > > function will update status like last_warning and underflow_seen on the > > timekeeper. > > > > If there are issues found this state is used to rate limit the warnings > > that get printed. > > > > This rate limiting doesn't really really work if stored in real_tk as > > the shadow timekeeper is overwritten onto real_tk at the end of every > > update_wall_time() call, resetting last_warning and other statuses. > > > > Fix rate limiting by using the shadow_timekeeper for > > timekeeping_check_update(). > > > > Fixes: commit 57d05a93ada7 ("time: Rework debugging variables so they aren't global") > > Signed-off-by: Stafford Horne > > Interesting! Thanks for submitting this! Out of curiosity, can you > also talk about the underlying issue that made you come across this > issue? > > thanks > -john