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 Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v2 0/6] arm64: perf: Proper cap_user_time* support Date: Wed, 15 Jul 2020 10:05:06 +0800 [thread overview] Message-ID: <20200715020512.20991-1-leo.yan@linaro.org> (raw) This patch set is rebased for Peter's patch set to support cap_user_time/cap_user_time_short ABI for Arm64, and export Arm arch timer counter related parameters from kernel to Perf tool. In this version, there have two changes comparing to Peter's original patch set [1]: The first change is for calculation 'time_zero', in the old patch it used the formula: userpg->time_zero -= (rd->epoch_cyc * rd->mult) >> rd->shift; From the testing, if 'rd->epoch_cyc' is a big counter value, then it's easily to cause overflow issue when multiply by the 'rd->mult'. So in this patch set, it changes to use quot/rem approach for the calculation and can avoid overflow: quot = rd->epoch_cyc >> rd->shift; rem = rd->epoch_cyc & (((u64)1 << rd->shift) - 1); ns = quot * rd->mult + ((rem * rd->mult) >> rd->shift); userpg->time_zero -= ns; The second change is to add new patch 'tools headers UAPI: Update tools's copy of linux/perf_event.h', it's used to update perf tool header so make sure the headers are consistent between kernel and user space. This patch set has been rebased on mainline kernel with the latest commit 11ba468877bb ("Linux 5.8-rc5"); it has been verified with Perf tool for Arm SPE timestamp enabling, the patch set for Arm SPE timestamp enabling will be sent out separately. [1] https://lkml.org/lkml/2020/5/12/481 Leo Yan (1): tools headers UAPI: Update tools's copy of linux/perf_event.h Peter Zijlstra (5): sched_clock: Expose struct clock_read_data arm64: perf: Implement correct cap_user_time arm64: perf: Only advertise cap_user_time for arch_timer perf: Add perf_event_mmap_page::cap_user_time_short ABI arm64: perf: Add cap_user_time_short arch/arm64/kernel/perf_event.c | 59 ++++++++++++++++++++------- include/linux/sched_clock.h | 28 +++++++++++++ include/uapi/linux/perf_event.h | 23 +++++++++-- kernel/time/sched_clock.c | 41 ++++++------------- tools/include/uapi/linux/perf_event.h | 23 +++++++++-- 5 files changed, 126 insertions(+), 48 deletions(-) -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
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 Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v2 0/6] arm64: perf: Proper cap_user_time* support Date: Wed, 15 Jul 2020 10:05:06 +0800 [thread overview] Message-ID: <20200715020512.20991-1-leo.yan@linaro.org> (raw) This patch set is rebased for Peter's patch set to support cap_user_time/cap_user_time_short ABI for Arm64, and export Arm arch timer counter related parameters from kernel to Perf tool. In this version, there have two changes comparing to Peter's original patch set [1]: The first change is for calculation 'time_zero', in the old patch it used the formula: userpg->time_zero -= (rd->epoch_cyc * rd->mult) >> rd->shift; From the testing, if 'rd->epoch_cyc' is a big counter value, then it's easily to cause overflow issue when multiply by the 'rd->mult'. So in this patch set, it changes to use quot/rem approach for the calculation and can avoid overflow: quot = rd->epoch_cyc >> rd->shift; rem = rd->epoch_cyc & (((u64)1 << rd->shift) - 1); ns = quot * rd->mult + ((rem * rd->mult) >> rd->shift); userpg->time_zero -= ns; The second change is to add new patch 'tools headers UAPI: Update tools's copy of linux/perf_event.h', it's used to update perf tool header so make sure the headers are consistent between kernel and user space. This patch set has been rebased on mainline kernel with the latest commit 11ba468877bb ("Linux 5.8-rc5"); it has been verified with Perf tool for Arm SPE timestamp enabling, the patch set for Arm SPE timestamp enabling will be sent out separately. [1] https://lkml.org/lkml/2020/5/12/481 Leo Yan (1): tools headers UAPI: Update tools's copy of linux/perf_event.h Peter Zijlstra (5): sched_clock: Expose struct clock_read_data arm64: perf: Implement correct cap_user_time arm64: perf: Only advertise cap_user_time for arch_timer perf: Add perf_event_mmap_page::cap_user_time_short ABI arm64: perf: Add cap_user_time_short arch/arm64/kernel/perf_event.c | 59 ++++++++++++++++++++------- include/linux/sched_clock.h | 28 +++++++++++++ include/uapi/linux/perf_event.h | 23 +++++++++-- kernel/time/sched_clock.c | 41 ++++++------------- tools/include/uapi/linux/perf_event.h | 23 +++++++++-- 5 files changed, 126 insertions(+), 48 deletions(-) -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-07-15 2:05 UTC|newest] Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-15 2:05 Leo Yan [this message] 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 2:05 ` Leo Yan 2020-07-15 5:56 ` Ahmed S. Darwish 2020-07-15 5:56 ` Ahmed S. Darwish 2020-07-15 6:54 ` Leo Yan 2020-07-15 6:54 ` Leo Yan 2020-07-15 7:21 ` Ahmed S. Darwish 2020-07-15 7:21 ` Ahmed S. Darwish 2020-07-15 8:12 ` Peter Zijlstra 2020-07-15 8:12 ` Peter Zijlstra 2020-07-15 8:14 ` peterz 2020-07-15 8:14 ` peterz 2020-07-15 9:23 ` Ahmed S. Darwish 2020-07-15 9:23 ` Ahmed S. Darwish 2020-07-15 9:52 ` Peter Zijlstra 2020-07-15 9:52 ` Peter Zijlstra 2020-07-15 11:59 ` [PATCH] time/sched_clock: Use raw_read_seqcount_latch() Ahmed S. Darwish 2020-07-15 15:29 ` Leo Yan 2020-07-15 15:58 ` Peter Zijlstra 2020-07-16 5:22 ` Leo Yan 2020-09-10 15:08 ` [tip: locking/core] time/sched_clock: Use raw_read_seqcount_latch() during suspend tip-bot2 for Ahmed S. Darwish 2020-07-15 2:05 ` [PATCH v2 2/6] arm64: perf: Implement correct cap_user_time Leo Yan 2020-07-15 2:05 ` Leo Yan 2020-07-15 8:38 ` Peter Zijlstra 2020-07-15 8:38 ` Peter Zijlstra 2020-07-15 15:39 ` Leo Yan 2020-07-15 15:39 ` Leo Yan 2020-07-15 2:05 ` [PATCH v2 3/6] arm64: perf: Only advertise cap_user_time for arch_timer Leo Yan 2020-07-15 2:05 ` Leo Yan 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 ` 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 ` 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 2:05 ` Leo Yan 2020-07-15 5:17 ` [PATCH v2 0/6] arm64: perf: Proper cap_user_time* support Ahmed S. Darwish 2020-07-15 5:17 ` Ahmed S. Darwish 2020-07-15 6:29 ` Leo Yan 2020-07-15 6:29 ` Leo Yan
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