lkml.org 
[lkml]   [2014]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC 4/5] perf: Add pmu callbacks to track event mapping and unmapping
Date
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
include/linux/perf_event.h | 7 +++++++
kernel/events/core.c | 9 +++++++++
2 files changed, 16 insertions(+)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 707617a8c0f6..88069e319a3f 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -206,6 +206,13 @@ struct pmu {
*/
int (*event_init) (struct perf_event *event);

+ /*
+ * Notification that the event was mapped or unmapped. Called
+ * in the context of the mapping task.
+ */
+ void (*event_mapped) (struct perf_event *event); /*optional*/
+ void (*event_unmapped) (struct perf_event *event); /*optional*/
+
#define PERF_EF_START 0x01 /* start the counter when adding */
#define PERF_EF_RELOAD 0x02 /* reload the counter when starting */
#define PERF_EF_UPDATE 0x04 /* update the counter when stopping */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 963bf139e2b2..dc73e9723748 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4008,6 +4008,9 @@ static void perf_mmap_open(struct vm_area_struct *vma)

atomic_inc(&event->mmap_count);
atomic_inc(&event->rb->mmap_count);
+
+ if (event->pmu->event_mapped)
+ event->pmu->event_mapped(event);
}

/*
@@ -4027,6 +4030,9 @@ static void perf_mmap_close(struct vm_area_struct *vma)
int mmap_locked = rb->mmap_locked;
unsigned long size = perf_data_size(rb);

+ if (event->pmu->event_unmapped)
+ event->pmu->event_unmapped(event);
+
atomic_dec(&rb->mmap_count);

if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
@@ -4228,6 +4234,9 @@ unlock:
vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &perf_mmap_vmops;

+ if (event->pmu->event_mapped)
+ event->pmu->event_mapped(event);
+
return ret;
}

--
1.9.3


\
 
 \ /
  Last update: 2014-10-15 01:21    [W:0.333 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site