From: Leo Yan <leo.yan@linaro.org> To: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, daniel.lezcano@linaro.org, tglx@linutronix.de, sboyd@codeaurora.org, john.stultz@linaro.org Subject: Re: [PATCH 5/5] arm64: perf: Add cap_user_time_short Date: Tue, 12 May 2020 22:11:26 +0800 [thread overview] Message-ID: <20200512141126.GD20352@leoy-ThinkPad-X240s> (raw) In-Reply-To: <20200512124451.061059334@infradead.org> On Tue, May 12, 2020 at 02:41:03PM +0200, Peter Zijlstra wrote: > This completes the ARM64 cap_user_time support. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > arch/arm64/kernel/perf_event.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > --- a/arch/arm64/kernel/perf_event.c > +++ b/arch/arm64/kernel/perf_event.c > @@ -1173,6 +1173,7 @@ void arch_perf_update_userpage(struct pe > > userpg->cap_user_time = 0; > userpg->cap_user_time_zero = 0; > + userpg->cap_user_time_short = 0; > > do { > rd = sched_clock_read_begin(&seq); > @@ -1183,13 +1184,13 @@ void arch_perf_update_userpage(struct pe > userpg->time_mult = rd->mult; > userpg->time_shift = rd->shift; > userpg->time_zero = rd->epoch_ns; > + userpg->time_cycle = rd->epoch_cyc; s/time_cycle/time_cycles, maybe consider to change the naming to 'time_cycle'. This patch set looks good to me after I tested it on Arm64 board. Thanks, Leo > + userpg->time_mask = rd->sched_clock_mask; > > /* > - * This isn't strictly correct, the ARM64 counter can be > - * 'short' and then we get funnies when it wraps. The correct > - * thing would be to extend the perf ABI with a cycle and mask > - * value, but because wrapping on ARM64 is very rare in > - * practise this 'works'. > + * Subtract the cycle base, such that software that > + * doesn't know about cap_user_time_short still 'works' > + * assuming no wraps. > */ > userpg->time_zero -= (rd->epoch_cyc * rd->mult) >> rd->shift; > > @@ -1214,4 +1215,5 @@ void arch_perf_update_userpage(struct pe > */ > userpg->cap_user_time = 1; > userpg->cap_user_time_zero = 1; > + userpg->cap_user_time_short = 1; > } > >
WARNING: multiple messages have this Message-ID (diff)
From: Leo Yan <leo.yan@linaro.org> To: Peter Zijlstra <peterz@infradead.org> Cc: Mark Rutland <mark.rutland@arm.com>, alexander.shishkin@linux.intel.com, Marc Zyngier <maz@kernel.org>, jolsa@redhat.com, daniel.lezcano@linaro.org, sboyd@codeaurora.org, linux-kernel@vger.kernel.org, acme@kernel.org, mingo@redhat.com, john.stultz@linaro.org, Catalin Marinas <catalin.marinas@arm.com>, tglx@linutronix.de, Will Deacon <will@kernel.org>, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 5/5] arm64: perf: Add cap_user_time_short Date: Tue, 12 May 2020 22:11:26 +0800 [thread overview] Message-ID: <20200512141126.GD20352@leoy-ThinkPad-X240s> (raw) In-Reply-To: <20200512124451.061059334@infradead.org> On Tue, May 12, 2020 at 02:41:03PM +0200, Peter Zijlstra wrote: > This completes the ARM64 cap_user_time support. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > arch/arm64/kernel/perf_event.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > --- a/arch/arm64/kernel/perf_event.c > +++ b/arch/arm64/kernel/perf_event.c > @@ -1173,6 +1173,7 @@ void arch_perf_update_userpage(struct pe > > userpg->cap_user_time = 0; > userpg->cap_user_time_zero = 0; > + userpg->cap_user_time_short = 0; > > do { > rd = sched_clock_read_begin(&seq); > @@ -1183,13 +1184,13 @@ void arch_perf_update_userpage(struct pe > userpg->time_mult = rd->mult; > userpg->time_shift = rd->shift; > userpg->time_zero = rd->epoch_ns; > + userpg->time_cycle = rd->epoch_cyc; s/time_cycle/time_cycles, maybe consider to change the naming to 'time_cycle'. This patch set looks good to me after I tested it on Arm64 board. Thanks, Leo > + userpg->time_mask = rd->sched_clock_mask; > > /* > - * This isn't strictly correct, the ARM64 counter can be > - * 'short' and then we get funnies when it wraps. The correct > - * thing would be to extend the perf ABI with a cycle and mask > - * value, but because wrapping on ARM64 is very rare in > - * practise this 'works'. > + * Subtract the cycle base, such that software that > + * doesn't know about cap_user_time_short still 'works' > + * assuming no wraps. > */ > userpg->time_zero -= (rd->epoch_cyc * rd->mult) >> rd->shift; > > @@ -1214,4 +1215,5 @@ void arch_perf_update_userpage(struct pe > */ > userpg->cap_user_time = 1; > userpg->cap_user_time_zero = 1; > + userpg->cap_user_time_short = 1; > } > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-05-12 14:11 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-12 12:40 [PATCH 0/5] arm64: perf: Proper cap_user_time* support Peter Zijlstra 2020-05-12 12:40 ` Peter Zijlstra 2020-05-12 12:40 ` [PATCH 1/5] sched_clock: Expose struct clock_read_data Peter Zijlstra 2020-05-12 12:40 ` Peter Zijlstra 2020-05-12 12:41 ` [PATCH 2/5] arm64: perf: Implement correct cap_user_time Peter Zijlstra 2020-05-12 12:41 ` Peter Zijlstra 2020-05-12 14:03 ` Leo Yan 2020-05-12 14:03 ` Leo Yan 2020-05-12 14:08 ` Peter Zijlstra 2020-05-12 14:08 ` Peter Zijlstra 2020-05-12 16:05 ` kbuild test robot 2020-05-12 16:05 ` kbuild test robot 2020-05-12 16:05 ` kbuild test robot 2020-05-12 12:41 ` [PATCH 3/5] arm64: perf: Only advertise cap_user_time for arch_timer Peter Zijlstra 2020-05-12 12:41 ` Peter Zijlstra 2020-05-12 12:41 ` [PATCH 4/5] perf: Add perf_event_mmap_page::cap_user_time_short ABI Peter Zijlstra 2020-05-12 12:41 ` Peter Zijlstra 2020-05-12 12:41 ` [PATCH 5/5] arm64: perf: Add cap_user_time_short Peter Zijlstra 2020-05-12 12:41 ` Peter Zijlstra 2020-05-12 14:11 ` Leo Yan [this message] 2020-05-12 14:11 ` Leo Yan 2020-05-12 16:59 ` kbuild test robot 2020-05-12 16:59 ` kbuild test robot 2020-05-12 16:59 ` kbuild test robot 2020-07-13 6:08 ` [PATCH 0/5] arm64: perf: Proper cap_user_time* support Leo Yan 2020-07-13 6:08 ` Leo Yan 2020-07-13 10:11 ` Will Deacon 2020-07-13 10:11 ` Will Deacon 2020-07-13 12:58 ` Leo Yan 2020-07-13 12:58 ` Leo Yan
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