[PATCH v2 30/32] perf,perf/x86: add hook perf_event_arch_exec

David Carrillo-Cisneros
2016-05-11T23:04:03Z

perf_event context switches events to newly exec'ed tasks using
perf_event_exec. Add a hook for such path.

In x86, perf_event_arch_exec is used to synchronize the software
cache of the PQR_ASSOC msr, setting the right RMID for the new task.

Reviewed-by: Stephane Eranian <eranian@google.com>
Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
arch/x86/include/asm/perf_event.h | 2 ++
include/linux/perf_event.h | 5 +++++
kernel/events/core.c | 1 +
3 files changed, 8 insertions(+)

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index a7d907f..e744398 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -334,6 +334,8 @@ extern struct cftype perf_event_cgrp_arch_subsys_cftypes[];
.dfl_cftypes = perf_event_cgrp_arch_subsys_cftypes, \
.legacy_cftypes = perf_event_cgrp_arch_subsys_cftypes,

+#define perf_event_arch_exec pqr_ctx_switch
+
#else

#define PERF_CGROUP_ARCH_CGRP_SUBSYS_ATTS
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f40b3aa..fa52e46 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1394,4 +1394,9 @@ static struct device_attribute format_attr_##_name = __ATTR_RO(_name)
#define PERF_CGROUP_ARCH_CGRP_SUBSYS_ATTS
#endif

+#ifndef perf_event_arch_exec
+#define perf_event_arch_exec() do { } while (0)
+#endif
+
+
#endif /* _LINUX_PERF_EVENT_H */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c3d9712..4f3a24f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6018,6 +6018,7 @@ void perf_event_exec(void)
true);
}
rcu_read_unlock();
+ perf_event_arch_exec();
}

struct remote_output {
--
2.8.0.rc3.226.g39d4020