Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH][RFC v5] timekeeping: Ignore the bogus sleep time if pm_trace is enabled | Date | Wed, 31 Aug 2016 02:31:46 +0200 |
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On Monday, August 29, 2016 12:40:39 AM Chen Yu wrote: > 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 <rjw@rjwysocki.net> > Cc: John Stultz <john.stultz@linaro.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Xunlei Pang <xlpang@redhat.com> > Cc: Zhang Rui <rui.zhang@intel.com> > Cc: linux-kernel@vger.kernel.org > Cc: linux-pm@vger.kernel.org > Suggested-by: Xunlei Pang <xlpang@redhat.com> > Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Suggested-by: Thomas Gleixner <tglx@linutronix.de> > Reported-by: Janek Kozicki <cosurgi@gmail.com> > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > --- > 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 <linux/export.h> > #include <linux/pnp.h> > #include <linux/of.h> > +#include <linux/pm-trace.h> > > #include <asm/vsyscall.h> > #include <asm/x86_init.h> > @@ -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; > + }
I'm not sure about this. Looks hackish.
> } > > > 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 <linux/stop_machine.h> > #include <linux/pvclock_gtod.h> > #include <linux/compiler.h> > +#include <linux/pm-trace.h> > > #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(); > } > > /**
Thanks, Rafael
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