From: Alexey Budankov <alexey.budankov@linux.intel.com>
Date: Wed, 23 Oct 2019 10:11:04 +0300
Subject: perf/core, perf/x86: Introduce swap_task_ctx() method at 'struct pmu'
Git-commit: fc1adfe306b71e094df636012f8c0fed971cad45
Patch-mainline: v5.5-rc1
References: jsc#SLE-13346
X-Info: dependent patch for 7b2c05a15d29d0570a0d21da1e4fd5cbc85cbf13
Declare swap_task_ctx() methods at the generic and x86 specific
pmu types to bridge calls to platform specific PMU code on optimized
context switch path between equivalent task perf event contexts.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/9a0aa84a-f062-9b64-3133-373658550c4b@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Tony Jones <tonyj@suse.de>
---
arch/x86/events/perf_event.h | 8 ++++++++
include/linux/perf_event.h | 9 +++++++++
2 files changed, 17 insertions(+)
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index ecacfbf4ebc1..5384317eaa16 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -682,6 +682,14 @@ struct x86_pmu {
*/
atomic_t lbr_exclusive[x86_lbr_exclusive_max];
+ /*
+ * perf task context (i.e. struct perf_event_context::task_ctx_data)
+ * switch helper to bridge calls from perf/core to perf/x86.
+ * See struct pmu::swap_task_ctx() usage for examples;
+ */
+ void (*swap_task_ctx)(struct perf_event_context *prev,
+ struct perf_event_context *next);
+
/*
* AMD bits
*/
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 4f77b22d47be..011dcbdbccc2 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -410,6 +410,15 @@ struct pmu {
*/
size_t task_ctx_size;
+ /*
+ * PMU specific parts of task perf event context (i.e. ctx->task_ctx_data)
+ * can be synchronized using this function. See Intel LBR callstack support
+ * implementation and Perf core context switch handling callbacks for usage
+ * examples.
+ */
+ void (*swap_task_ctx) (struct perf_event_context *prev,
+ struct perf_event_context *next);
+ /* optional */
/*
* Set up pmu-private data structures for an AUX area