diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-07-16 13:11:27 +0800 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-07-20 11:50:47 +0100 |
| commit | 279a811eb520594fac3cd3a541e6c7ea50072ac9 (patch) | |
| tree | 26c3211c1a4c9238fd368446f88bc07b3cb98a9f /arch/arm64/kernel | |
| parent | 950b74ddefc4a42add8b1ae0170aa309338ffe73 (diff) | |
| download | lwn-279a811eb520594fac3cd3a541e6c7ea50072ac9.tar.gz lwn-279a811eb520594fac3cd3a541e6c7ea50072ac9.zip | |
arm64: perf: Only advertise cap_user_time for arch_timer
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>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/perf_event.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 3bbbc22a5148..674edc7ba8ca 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -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; } |