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-rw-r--r--arch/x86/kernel/cpu/perf_event.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index a7c7305030cc..8355c84b9729 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1884,6 +1884,7 @@ static struct pmu pmu = {
void arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
{
userpg->cap_usr_time = 0;
+ userpg->cap_usr_time_zero = 0;
userpg->cap_usr_rdpmc = x86_pmu.attr_rdpmc;
userpg->pmc_width = x86_pmu.cntval_bits;
@@ -1897,6 +1898,11 @@ void arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
userpg->time_mult = this_cpu_read(cyc2ns);
userpg->time_shift = CYC2NS_SCALE_FACTOR;
userpg->time_offset = this_cpu_read(cyc2ns_offset) - now;
+
+ if (sched_clock_stable && !check_tsc_disabled()) {
+ userpg->cap_usr_time_zero = 1;
+ userpg->time_zero = this_cpu_read(cyc2ns_offset);
+ }
}
/*