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| author | Peter Zijlstra <peterz@infradead.org> | 2023-01-26 18:08:36 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-01-31 17:01:47 +0300 |
| commit | 8739c6811572b087decd561f96382087402cc343 (patch) | |
| tree | 60330c4df92998fd1994afa131ebab2b24ca67b2 /arch/x86/xen/time.c | |
| parent | 5c9da9fe826d4a0d84bb322cca27cc8ad8d23b24 (diff) | |
| download | linux-8739c6811572b087decd561f96382087402cc343.tar.xz | |
sched/clock/x86: Mark sched_clock() noinstr
In order to use sched_clock() from noinstr code, mark it and all it's
implenentations noinstr.
The whole pvclock thing (used by KVM/Xen) is a bit of a pain,
since it calls out to watchdogs, create a
pvclock_clocksource_read_nowd() variant doesn't do that and can be
noinstr.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230126151323.702003578@infradead.org
Diffstat (limited to 'arch/x86/xen/time.c')
| -rw-r--r-- | arch/x86/xen/time.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 9ef0a5cca96e..6b8836deb738 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -60,9 +60,17 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs) return xen_clocksource_read(); } -static u64 xen_sched_clock(void) +static noinstr u64 xen_sched_clock(void) { - return xen_clocksource_read() - xen_sched_clock_offset; + struct pvclock_vcpu_time_info *src; + u64 ret; + + preempt_disable_notrace(); + src = &__this_cpu_read(xen_vcpu)->time; + ret = pvclock_clocksource_read_nowd(src); + ret -= xen_sched_clock_offset; + preempt_enable_notrace(); + return ret; } static void xen_read_wallclock(struct timespec64 *ts) |