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From: kan.liang@linux.intel.com
To: peterz@infradead.org, acme@kernel.org, mingo@redhat.com,
	linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, jolsa@kernel.org, eranian@google.com,
	alexander.shishkin@linux.intel.com, ak@linux.intel.com,
	Kan Liang <kan.liang@linux.intel.com>
Subject: [PATCH 1/9] perf/core: Support a REMOVE transaction
Date: Tue, 21 May 2019 14:40:47 -0700	[thread overview]
Message-ID: <20190521214055.31060-2-kan.liang@linux.intel.com> (raw)
In-Reply-To: <20190521214055.31060-1-kan.liang@linux.intel.com>

From: Andi Kleen <ak@linux.intel.com>

The TopDown events can be collected per thread/process on Icelake. To
use TopDown through RDPMC in applications, the metrics and slots MSR
values have to be saved/restored during context switching.
It is useful to have a remove transaction when the counter is
unscheduled, so that the values can be saved correctly.

Add a remove transaction to the perf core.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
 arch/x86/events/core.c     | 3 +--
 include/linux/perf_event.h | 1 +
 kernel/events/core.c       | 5 +++++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index f0e4804515d8..e075de494dfd 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1856,8 +1856,7 @@ static inline void x86_pmu_read(struct perf_event *event)
  * Set the flag to make pmu::enable() not perform the
  * schedulability test, it will be performed at commit time
  *
- * We only support PERF_PMU_TXN_ADD transactions. Save the
- * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
+ * Save the transaction flags and ignore non-PERF_PMU_TXN_ADD
  * transactions.
  */
 static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 5beb5cde3d56..973b7f8ce8e9 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -233,6 +233,7 @@ struct perf_event;
  */
 #define PERF_PMU_TXN_ADD  0x1		/* txn to add/schedule event on PMU */
 #define PERF_PMU_TXN_READ 0x2		/* txn to read event group from PMU */
+#define PERF_PMU_TXN_REMOVE 0x4		/* txn to remove event on PMU */
 
 /**
  * pmu::capabilities flags
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 118ad1aef6af..f204166f6bc8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2032,6 +2032,7 @@ group_sched_out(struct perf_event *group_event,
 		struct perf_cpu_context *cpuctx,
 		struct perf_event_context *ctx)
 {
+	struct pmu *pmu = ctx->pmu;
 	struct perf_event *event;
 
 	if (group_event->state != PERF_EVENT_STATE_ACTIVE)
@@ -2039,6 +2040,8 @@ group_sched_out(struct perf_event *group_event,
 
 	perf_pmu_disable(ctx->pmu);
 
+	pmu->start_txn(pmu, PERF_PMU_TXN_REMOVE);
+
 	event_sched_out(group_event, cpuctx, ctx);
 
 	/*
@@ -2051,6 +2054,8 @@ group_sched_out(struct perf_event *group_event,
 
 	if (group_event->attr.exclusive)
 		cpuctx->exclusive = 0;
+
+	pmu->commit_txn(pmu);
 }
 
 #define DETACH_GROUP	0x01UL
-- 
2.14.5


  reply	other threads:[~2019-05-21 21:41 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-21 21:40 [PATCH 0/9] TopDown metrics support for Icelake kan.liang
2019-05-21 21:40 ` kan.liang [this message]
2019-05-21 21:40 ` [PATCH 2/9] perf/x86/intel: Basic support for metrics counters kan.liang
2019-05-28 12:05   ` Peter Zijlstra
2019-05-28 18:20     ` Liang, Kan
2019-05-28 12:15   ` Peter Zijlstra
2019-05-28 18:21     ` Liang, Kan
2019-05-29  7:28       ` Peter Zijlstra
2019-05-29 14:40         ` Liang, Kan
2019-05-29 16:46           ` Peter Zijlstra
2019-05-29  8:14   ` Peter Zijlstra
2019-05-21 21:40 ` [PATCH 3/9] perf/x86/intel: Support overflows on SLOTS kan.liang
2019-05-28 12:20   ` Peter Zijlstra
2019-05-28 18:22     ` Liang, Kan
2019-05-21 21:40 ` [PATCH 4/9] perf/x86/intel: Support hardware TopDown metrics kan.liang
2019-05-28 12:43   ` Peter Zijlstra
2019-05-28 18:23     ` Liang, Kan
2019-05-29  7:30       ` Peter Zijlstra
2019-05-28 12:53   ` Peter Zijlstra
2019-05-28 12:56   ` Peter Zijlstra
2019-05-28 13:32     ` Peter Zijlstra
2019-05-28 13:30   ` Peter Zijlstra
2019-05-28 18:24     ` Liang, Kan
2019-05-29  7:34       ` Peter Zijlstra
2019-05-29 14:41         ` Liang, Kan
2019-05-28 13:43   ` Peter Zijlstra
2019-05-28 18:24     ` Liang, Kan
2019-05-29  7:54       ` Peter Zijlstra
2019-05-29 14:42         ` Liang, Kan
2019-05-29 16:58           ` Peter Zijlstra
2019-06-04 20:39             ` Liang, Kan
2019-05-28 13:48   ` Peter Zijlstra
2019-05-28 18:24     ` Liang, Kan
2019-05-29  7:57       ` Peter Zijlstra
2019-05-29 14:42         ` Liang, Kan
2019-05-21 21:40 ` [PATCH 5/9] perf/x86/intel: Set correct weight for TopDown metrics events kan.liang
2019-05-28 13:50   ` Peter Zijlstra
2019-05-21 21:40 ` [PATCH 6/9] perf/x86/intel: Export new TopDown metrics events for Icelake kan.liang
2019-05-21 21:40 ` [PATCH 7/9] perf/x86/intel: Disable sampling read slots and topdown kan.liang
2019-05-28 13:52   ` Peter Zijlstra
2019-05-28 18:25     ` Liang, Kan
2019-05-29  7:58       ` Peter Zijlstra
2019-05-21 21:40 ` [PATCH 8/9] perf, tools, stat: Support new per thread TopDown metrics kan.liang
2019-05-21 21:40 ` [PATCH 9/9] perf, tools: Add documentation for topdown metrics kan.liang

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