From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656AbbFKW4a (ORCPT ); Thu, 11 Jun 2015 18:56:30 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:36094 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242AbbFKWzG (ORCPT ); Thu, 11 Jun 2015 18:55:06 -0400 From: John Stultz To: linux-kernel@vger.kernel.org Cc: John Stultz , Thomas Gleixner , Preeti U Murthy , Peter Zijlstra , Viresh Kumar , Marcelo Tosatti , Frederic Weisbecker , Ingo Molnar Subject: [PATCH 1/5] time: Move clock_was_set_seq update to before we update the shadow-timekeeper Date: Thu, 11 Jun 2015 15:54:53 -0700 Message-Id: <1434063297-28657-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1434063297-28657-1-git-send-email-john.stultz@linaro.org> References: <1434063297-28657-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It was reported that 868a3e915f7f5eba (hrtimer: Make offset update smarter) was causing timer problems after suspend/resume. The problem with that change is the modification to clock_was_set_seq in timekeeping_update is done prior to mirroring the time state to the shadow-timekeeper. Thus the next time we do update_wall_time() the updated sequence is overwritten by whats in the shadow copy. This patch moves the shadow-timekeeper mirroring to the end of the function, after all updates have been made, so all data is kept in sync. (This patch also affects the update_fast_timekeeper calls which were also problematically done prior to the mirroring). Cc: Thomas Gleixner Cc: Preeti U Murthy Cc: Peter Zijlstra Cc: Viresh Kumar Cc: Marcelo Tosatti Cc: Frederic Weisbecker Cc: Ingo Molnar Reported-by: Jeremiah Mahler Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 90ed5db..849b932 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -585,15 +585,19 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) update_vsyscall(tk); update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); - if (action & TK_MIRROR) - memcpy(&shadow_timekeeper, &tk_core.timekeeper, - sizeof(tk_core.timekeeper)); - update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); if (action & TK_CLOCK_WAS_SET) tk->clock_was_set_seq++; + /* + * The mirroring of the data to the shadow-timekeeper needs + * to happen last here to ensure we don't over-write the + * timekeeper structure on the next update with stale data + */ + if (action & TK_MIRROR) + memcpy(&shadow_timekeeper, &tk_core.timekeeper, + sizeof(tk_core.timekeeper)); } /** -- 1.9.1