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arm64: perf: Only advertise cap_user_time for arch_timer

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When sched_clock is running on anything other than arch_timer, don't
advertise cap_user_time*.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20200716051130.4359-5-leo.yan@linaro.org
Requested-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Peter Zijlstra 2020-07-16 13:11:27 +08:00 committed by Will Deacon
parent 950b74ddef
commit 279a811eb5
1 changed files with 13 additions and 6 deletions
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19
arch/arm64/kernel/perf_event.c
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@ -13,6 +13,8 @@
#include <asm/sysreg.h>
#include <asm/virt.h>
#include <clocksource/arm_arch_timer.h>
#include <linux/acpi.h>
#include <linux/clocksource.h>
#include <linux/kvm_host.h>
@ -1173,16 +1175,15 @@ void arch_perf_update_userpage(struct perf_event *event,
unsigned int seq;
u64 ns;
/*
* Internal timekeeping for enabled/running/stopped times
* is always computed with the sched_clock.
*/
userpg->cap_user_time = 1;
userpg->cap_user_time_zero = 1;
userpg->cap_user_time = 0;
userpg->cap_user_time_zero = 0;
do {
rd = sched_clock_read_begin(&seq);
if (rd->read_sched_clock != arch_timer_read_counter)
return;
userpg->time_mult = rd->mult;
userpg->time_shift = rd->shift;
userpg->time_zero = rd->epoch_ns;
@ -1212,4 +1213,10 @@ void arch_perf_update_userpage(struct perf_event *event,
userpg->time_mult >>= 1;
}
/*
* Internal timekeeping for enabled/running/stopped times
* is always computed with the sched_clock.
*/
userpg->cap_user_time = 1;
userpg->cap_user_time_zero = 1;
}