The patch titled
sched_clock: prevent scd->clock from moving backwards
has been added to the -mm tree. Its filename is
sched_clock-prevent-scd-clock-from-moving-backwards-take-2.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: sched_clock: prevent scd->clock from moving backwards
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Redo:
5b7dba4: sched_clock: prevent scd->clock from moving backwards
which had to be reverted due to s2ram hangs:
ca7e716: Revert "sched_clock: prevent scd->clock from moving backwards"
... this time with resume restoring GTOD later in the sequence
taken into account as well.
The "timekeeping_suspended" flag is not very nice but we cannot call into
GTOD before it has been properly resumed and the scheduler will run very
early in the resume sequence.
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Reported-by: Jayson King <dev@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/time.h | 1 +
kernel/sched_clock.c | 5 ++++-
kernel/time/timekeeping.c | 7 +++++--
3 files changed, 10 insertions(+), 3 deletions(-)
diff -puN include/linux/time.h~sched_clock-prevent-scd-clock-from-moving-backwards-take-2 include/linux/time.h
--- a/include/linux/time.h~sched_clock-prevent-scd-clock-from-moving-backwards-take-2
+++ a/include/linux/time.h
@@ -105,6 +105,7 @@ extern unsigned long read_persistent_clo
extern int update_persistent_clock(struct timespec now);
extern int no_sync_cmos_clock __read_mostly;
void timekeeping_init(void);
+extern int timekeeping_suspended;
unsigned long get_seconds(void);
struct timespec current_kernel_time(void);
diff -puN kernel/sched_clock.c~sched_clock-prevent-scd-clock-from-moving-backwards-take-2 kernel/sched_clock.c
--- a/kernel/sched_clock.c~sched_clock-prevent-scd-clock-from-moving-backwards-take-2
+++ a/kernel/sched_clock.c
@@ -124,7 +124,7 @@ static u64 __update_sched_clock(struct s
clock = scd->tick_gtod + delta;
min_clock = wrap_max(scd->tick_gtod, scd->clock);
- max_clock = scd->tick_gtod + TICK_NSEC;
+ max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
clock = wrap_max(clock, min_clock);
clock = wrap_min(clock, max_clock);
@@ -227,6 +227,9 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep
*/
void sched_clock_idle_wakeup_event(u64 delta_ns)
{
+ if (timekeeping_suspended)
+ return;
+
sched_clock_tick();
touch_softlockup_watchdog();
}
diff -puN kernel/time/timekeeping.c~sched_clock-prevent-scd-clock-from-moving-backwards-take-2 kernel/time/timekeeping.c
--- a/kernel/time/timekeeping.c~sched_clock-prevent-scd-clock-from-moving-backwards-take-2
+++ a/kernel/time/timekeeping.c
@@ -46,6 +46,9 @@ struct timespec xtime __attribute__ ((al
struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
static unsigned long total_sleep_time; /* seconds */
+/* flag for if timekeeping is suspended */
+int __read_mostly timekeeping_suspended;
+
static struct timespec xtime_cache __attribute__ ((aligned (16)));
void update_xtime_cache(u64 nsec)
{
@@ -92,6 +95,8 @@ void getnstimeofday(struct timespec *ts)
unsigned long seq;
s64 nsecs;
+ WARN_ON(timekeeping_suspended);
+
do {
seq = read_seqbegin(&xtime_lock);
@@ -305,8 +310,6 @@ void __init timekeeping_init(void)
write_sequnlock_irqrestore(&xtime_lock, flags);
}
-/* flag for if timekeeping is suspended */
-static int timekeeping_suspended;
/* time in seconds when suspend began */
static unsigned long timekeeping_suspend_time;
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
origin.patch
linux-next.patch
clocksource-pass-clocksource-to-read-callback.patch
clocksource-add-enable-and-disable-callbacks.patch
sched_clock-prevent-scd-clock-from-moving-backwards-take-2.patch
irq-free-setup_irq-interrupt-using-free_irq.patch
mm-invoke-oom-killer-from-page-fault.patch
mm-invoke-oom-killer-from-page-fault-fix.patch
mm-invoke-oom-killer-from-page-fault-fix-fix-2.patch
allow-times-and-time-system-calls-to-return-small-negative-values.patch
smp_call_function_single-be-slightly-less-stupid.patch
kprobes-add-kprobe_insn_mutex-and-cleanup-arch_remove_kprobe.patch
unaligned-wire-up-trivial-arches-for-new-common-unaligned-header.patch
remove-lots-of-double-semicolons.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
