From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Yu Subject: [PATCH][RFC v5] timekeeping: Ignore the bogus sleep time if pm_trace is enabled Date: Mon, 29 Aug 2016 00:40:39 +0800 Message-ID: <1472402439-1146-1-git-send-email-yu.c.chen@intel.com> Return-path: Received: from mga14.intel.com ([192.55.52.115]:14231 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755754AbcH1Qct (ORCPT ); Sun, 28 Aug 2016 12:32:49 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: x86@kernel.org Cc: Thomas Gleixner , John Stultz , Ingo Molnar , "H. Peter Anvin" , linux-kernel@vger.kernel.org, Xunlei Pang , "Rafael J. Wysocki" , Chen Yu , "3.17+" , Zhang Rui , linux-pm@vger.kernel.org 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, and we have fixed it in recent kernel. However 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, or 2. rtc is used to calculate the sleep time in rtc_resume. Cc: stable@vger.kernel.org (3.17+) 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: Xunlei Pang Suggested-by: Rafael J. Wysocki Suggested-by: Thomas Gleixner Reported-by: Janek Kozicki Signed-off-by: Chen Yu --- arch/x86/kernel/rtc.c | 12 ++++++++++++ kernel/time/timekeeping.c | 3 ++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 79c6311c..5c28197 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -144,6 +145,17 @@ int update_persistent_clock(struct timespec now) void read_persistent_clock(struct timespec *ts) { x86_platform.get_wallclock(ts); + + /* + * Make rtc-based persistent clock unusable + * if pm_trace is enabled, only take effect + * for timekeeping_suspend/resume. + */ + if (pm_trace_is_enabled() && + x86_platform.get_wallclock == mach_get_cmos_time) { + ts->tv_sec = 0; + ts->tv_nsec = 0; + } } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3b65746..9af885d 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" @@ -1551,7 +1552,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk, */ bool timekeeping_rtc_skipresume(void) { - return sleeptime_injected; + return sleeptime_injected || pm_trace_is_enabled(); } /** -- 2.7.4