From patchwork Thu Aug 18 10:43:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Chen, Yu C" X-Patchwork-Id: 9287347 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BB05460574 for ; Thu, 18 Aug 2016 10:36:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC31C28A39 for ; Thu, 18 Aug 2016 10:36:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A098A28A41; Thu, 18 Aug 2016 10:36:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE63928A39 for ; Thu, 18 Aug 2016 10:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752431AbcHRKgt (ORCPT ); Thu, 18 Aug 2016 06:36:49 -0400 Received: from mga11.intel.com ([192.55.52.93]:5785 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751442AbcHRKgs (ORCPT ); Thu, 18 Aug 2016 06:36:48 -0400 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP; 18 Aug 2016 03:35:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,539,1464678000"; d="scan'208";a="157713478" Received: from sharon.sh.intel.com ([10.239.160.134]) by fmsmga004.fm.intel.com with ESMTP; 18 Aug 2016 03:35:48 -0700 From: Chen Yu To: linux-pm@vger.kernel.org Cc: Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, Chen Yu , "Rafael J . Wysocki" , John Stultz , Thomas Gleixner , Xunlei Pang , Zhang Rui , linux-kernel@vger.kernel.org Subject: [PATCH][RFC v4] timekeeping: ignore the bogus sleep time if pm_trace is enabled Date: Thu, 18 Aug 2016 18:43:39 +0800 Message-Id: <1471517019-15216-1-git-send-email-yu.c.chen@intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Previously we encountered some memory overflow issues due to the bogus sleep time brought by inconsistent rtc, which is triggered when pm_trace is enabled, please refer to: https://patchwork.kernel.org/patch/9286365/ It's improper in the first place to call __timekeeping_inject_sleeptime() in case that pm_trace is enabled simply because that "hash" time value will wreckage the timekeeping subsystem. So this patch ignores the sleep time if pm_trace is enabled in the following situation: 1. rtc is used as persist clock to compensate for sleep time, (because system does not have a nonstop clocksource) or 2. rtc is used to calculate the sleep time in rtc_resume. Cc: Rafael J. Wysocki Cc: John Stultz Cc: Thomas Gleixner Cc: Xunlei Pang Cc: Zhang Rui Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Suggested-by: Rafael J. Wysocki Reported-by: Janek Kozicki Signed-off-by: Chen Yu --- arch/x86/kernel/rtc.c | 7 +++++++ kernel/time/timekeeping.c | 14 +++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 79c6311c..6039138 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -146,6 +147,12 @@ void read_persistent_clock(struct timespec *ts) x86_platform.get_wallclock(ts); } +bool persistent_clock_is_usable(void) +{ + /* Unusable if pm_trace is enabled. */ + return !((x86_platform.get_wallclock == mach_get_cmos_time) && + pm_trace_is_enabled()); +} static struct resource rtc_resources[] = { [0] = { diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3b65746..3122bd2b 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "tick-internal.h" #include "ntp_internal.h" @@ -1450,6 +1451,11 @@ void __weak read_boot_clock64(struct timespec64 *ts) ts->tv_nsec = 0; } +bool __weak persistent_clock_is_usable(void) +{ + return true; +} + /* Flag for if timekeeping_resume() has injected sleeptime */ static bool sleeptime_injected; @@ -1551,7 +1557,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk, */ bool timekeeping_rtc_skipresume(void) { - return sleeptime_injected; + return sleeptime_injected || pm_trace_is_enabled(); } /** @@ -1662,6 +1668,12 @@ void timekeeping_resume(void) } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); sleeptime_injected = true; + /* + * If rtc is used as persist clock thus it + * would be bogus when pm_trace is enabled. + */ + if (!persistent_clock_is_usable()) + sleeptime_injected = false; } if (sleeptime_injected)