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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-08 01:42:34 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-08 01:42:34 +0300
commit609b07b72d3caaa8eed3a238886467946b78fa5e (patch)
treeb12ee470ed68675b3bbe4c0dcfa63a9978821fce /arch/x86/kernel/tsc.c
parentc3abcabe813b4a0976b58f7e6c1e63b2070c8dda (diff)
parentf94c8d116997597fc00f0812b0ab9256e7b0c58f (diff)
downloadlinux-609b07b72d3caaa8eed3a238886467946b78fa5e.tar.xz
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar: "A fix for KVM's scheduler clock which (erroneously) was always marked unstable, a fix for RT/DL load balancing, plus latency fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface sched/core: Fix pick_next_task() for RT,DL sched/fair: Make select_idle_cpu() more aggressive
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c35
1 files changed, 23 insertions, 12 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 46bcda4cb1c2..4f7a9833d8e5 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -327,9 +327,16 @@ unsigned long long sched_clock(void)
{
return paravirt_sched_clock();
}
+
+static inline bool using_native_sched_clock(void)
+{
+ return pv_time_ops.sched_clock == native_sched_clock;
+}
#else
unsigned long long
sched_clock(void) __attribute__((alias("native_sched_clock")));
+
+static inline bool using_native_sched_clock(void) { return true; }
#endif
int check_tsc_unstable(void)
@@ -1112,8 +1119,10 @@ static void tsc_cs_mark_unstable(struct clocksource *cs)
{
if (tsc_unstable)
return;
+
tsc_unstable = 1;
- clear_sched_clock_stable();
+ if (using_native_sched_clock())
+ clear_sched_clock_stable();
disable_sched_clock_irqtime();
pr_info("Marking TSC unstable due to clocksource watchdog\n");
}
@@ -1135,18 +1144,20 @@ static struct clocksource clocksource_tsc = {
void mark_tsc_unstable(char *reason)
{
- if (!tsc_unstable) {
- tsc_unstable = 1;
+ if (tsc_unstable)
+ return;
+
+ tsc_unstable = 1;
+ if (using_native_sched_clock())
clear_sched_clock_stable();
- disable_sched_clock_irqtime();
- pr_info("Marking TSC unstable due to %s\n", reason);
- /* Change only the rating, when not registered */
- if (clocksource_tsc.mult)
- clocksource_mark_unstable(&clocksource_tsc);
- else {
- clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE;
- clocksource_tsc.rating = 0;
- }
+ disable_sched_clock_irqtime();
+ pr_info("Marking TSC unstable due to %s\n", reason);
+ /* Change only the rating, when not registered */
+ if (clocksource_tsc.mult) {
+ clocksource_mark_unstable(&clocksource_tsc);
+ } else {
+ clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE;
+ clocksource_tsc.rating = 0;
}
}