From: Stephen Boyd <sboyd@codeaurora.org> To: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 4/7] ARM: perf_event: Add hook for event index clearing Date: Fri, 7 Feb 2014 13:01:22 -0800 [thread overview] Message-ID: <1391806885-24210-5-git-send-email-sboyd@codeaurora.org> (raw) In-Reply-To: <1391806885-24210-1-git-send-email-sboyd@codeaurora.org> On Krait processors we have a many-to-one relationship between raw CPU events and the event programmed into the PMNx counter. Two raw CPU events could map to the same value programmed in the PMNx counter. To avoid this problem, we check for collisions during the get_event_idx() callback by setting a bit in a bitmap whenever a certain event is used in a PMNx counter (see the next patch). Unfortunately, we don't have a hook to clear this bit in the bitmap when the event is deleted so let's add an optional clear_event_idx() callback for this purpose. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> --- arch/arm/include/asm/pmu.h | 2 ++ arch/arm/kernel/perf_event.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index f24edad26c70..ae1919be8f98 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -71,6 +71,8 @@ struct arm_pmu { void (*disable)(struct perf_event *event); int (*get_event_idx)(struct pmu_hw_events *hw_events, struct perf_event *event); + void (*clear_event_idx)(struct pmu_hw_events *hw_events, + struct perf_event *event); int (*set_event_filter)(struct hw_perf_event *evt, struct perf_event_attr *attr); u32 (*read_counter)(struct perf_event *event); diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index b0c8489018d3..361a1aaee7c8 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -207,6 +207,8 @@ armpmu_del(struct perf_event *event, int flags) armpmu_stop(event, PERF_EF_UPDATE); hw_events->events[idx] = NULL; clear_bit(idx, hw_events->used_mask); + if (armpmu->clear_event_idx) + armpmu->clear_event_idx(hw_events, event); perf_event_update_userpage(event); } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation
WARNING: multiple messages have this Message-ID (diff)
From: sboyd@codeaurora.org (Stephen Boyd) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 4/7] ARM: perf_event: Add hook for event index clearing Date: Fri, 7 Feb 2014 13:01:22 -0800 [thread overview] Message-ID: <1391806885-24210-5-git-send-email-sboyd@codeaurora.org> (raw) In-Reply-To: <1391806885-24210-1-git-send-email-sboyd@codeaurora.org> On Krait processors we have a many-to-one relationship between raw CPU events and the event programmed into the PMNx counter. Two raw CPU events could map to the same value programmed in the PMNx counter. To avoid this problem, we check for collisions during the get_event_idx() callback by setting a bit in a bitmap whenever a certain event is used in a PMNx counter (see the next patch). Unfortunately, we don't have a hook to clear this bit in the bitmap when the event is deleted so let's add an optional clear_event_idx() callback for this purpose. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> --- arch/arm/include/asm/pmu.h | 2 ++ arch/arm/kernel/perf_event.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index f24edad26c70..ae1919be8f98 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -71,6 +71,8 @@ struct arm_pmu { void (*disable)(struct perf_event *event); int (*get_event_idx)(struct pmu_hw_events *hw_events, struct perf_event *event); + void (*clear_event_idx)(struct pmu_hw_events *hw_events, + struct perf_event *event); int (*set_event_filter)(struct hw_perf_event *evt, struct perf_event_attr *attr); u32 (*read_counter)(struct perf_event *event); diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index b0c8489018d3..361a1aaee7c8 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -207,6 +207,8 @@ armpmu_del(struct perf_event *event, int flags) armpmu_stop(event, PERF_EF_UPDATE); hw_events->events[idx] = NULL; clear_bit(idx, hw_events->used_mask); + if (armpmu->clear_event_idx) + armpmu->clear_event_idx(hw_events, event); perf_event_update_userpage(event); } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2014-02-07 21:01 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-02-07 21:01 [PATCH v3 0/7] Support Krait CPU PMUs Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 1/7] ARM: perf_event: Support percpu irqs for the CPU PMU Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 2/7] ARM: perf_event: Assign pdev pointer earlier for CPU PMUs Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 3/7] ARM: perf_event: Add basic support for Krait " Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd [this message] 2014-02-07 21:01 ` [PATCH v3 4/7] ARM: perf_event: Add hook for event index clearing Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 5/7] ARM: perf_event: Fully support Krait CPU PMU events Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 6/7] devicetree: bindings: Document Krait performance monitor units (PMU) Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd 2014-02-07 21:01 ` [PATCH v3 7/7] ARM: dts: msm: Add krait-pmu to platforms with Krait CPUs Stephen Boyd 2014-02-07 21:01 ` Stephen Boyd
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