From: Leo Yan <leo.yan@linaro.org>
To: Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul Cercueil <paul@crapouillou.net>,
"Ben Dooks (Codethink)" <ben.dooks@codethink.co.uk>,
"Ahmed S. Darwish" <a.darwish@linutronix.de>,
Adrian Hunter <adrian.hunter@intel.com>,
Kan Liang <kan.liang@linux.intel.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 3/6] arm64: perf: Only advertise cap_user_time for arch_timer
Date: Wed, 15 Jul 2020 10:05:09 +0800 [thread overview]
Message-ID: <20200715020512.20991-4-leo.yan@linaro.org> (raw)
In-Reply-To: <20200715020512.20991-1-leo.yan@linaro.org>
From: Peter Zijlstra <peterz@infradead.org>
When sched_clock is running on anything other than arch_timer, don't
advertise cap_user_time*.
Requested-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/arm64/kernel/perf_event.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 35c2c737d4af..76f6afd28b48 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>
@@ -1170,16 +1172,15 @@ void arch_perf_update_userpage(struct perf_event *event,
unsigned int seq;
u64 quot, rem, 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;
@@ -1211,4 +1212,10 @@ 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;
}
--
2.17.1
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next prev parent reply other threads:[~2020-07-15 2:13 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 2:05 [PATCH v2 0/6] arm64: perf: Proper cap_user_time* support Leo Yan
2020-07-15 2:05 ` [PATCH v2 1/6] sched_clock: Expose struct clock_read_data Leo Yan
2020-07-15 5:56 ` Ahmed S. Darwish
2020-07-15 6:54 ` Leo Yan
2020-07-15 7:21 ` Ahmed S. Darwish
2020-07-15 8:12 ` Peter Zijlstra
2020-07-15 8:14 ` peterz
2020-07-15 9:23 ` Ahmed S. Darwish
2020-07-15 9:52 ` Peter Zijlstra
2020-07-15 2:05 ` [PATCH v2 2/6] arm64: perf: Implement correct cap_user_time Leo Yan
2020-07-15 8:38 ` Peter Zijlstra
2020-07-15 15:39 ` Leo Yan
2020-07-15 2:05 ` Leo Yan [this message]
2020-07-15 2:05 ` [PATCH v2 4/6] perf: Add perf_event_mmap_page::cap_user_time_short ABI Leo Yan
2020-07-15 2:05 ` [PATCH v2 5/6] arm64: perf: Add cap_user_time_short Leo Yan
2020-07-15 2:05 ` [PATCH v2 6/6] tools headers UAPI: Update tools's copy of linux/perf_event.h Leo Yan
2020-07-15 5:17 ` [PATCH v2 0/6] arm64: perf: Proper cap_user_time* support Ahmed S. Darwish
2020-07-15 6:29 ` Leo Yan
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