This patch adds a new software event for munmaps. It will allows
users to profile changes to address space. munmaps will be tracked
with mmaps.
Signed-off-by: Eric B Munson <ebmunson@xxxxxxxxxx>
Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
---
include/linux/perf_event.h | 6 ++++-
kernel/perf_event.c | 49 +++++++++++++++++++++++++++++++++++++++---
mm/mmap.c | 2 +
tools/perf/builtin-record.c | 1 +
4 files changed, 53 insertions(+), 5 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 716f99b..937dd93 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -215,8 +215,9 @@ struct perf_event_attr {
*/
precise_ip : 2, /* skid constraint */
mmap_data : 1, /* non-exec mmap data */
+ munmap : 1, /* include munmap events */
- __reserved_1 : 46;
+ __reserved_1 : 45;
union {
__u32 wakeup_events; /* wakeup every n events */
@@ -341,6 +342,7 @@ enum perf_event_type {
* };
*/
PERF_RECORD_MMAP = 1,
+ PERF_RECORD_MUNMAP = 10,
/*
* struct {
@@ -969,6 +971,8 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
}
extern void perf_event_mmap(struct vm_area_struct *vma);
+extern void perf_event_munmap(struct vm_area_struct *vma, unsigned long start,
+ size_t len);
extern struct perf_guest_info_callbacks *perf_guest_cbs;
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 403d180..2d24e4e 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -46,6 +46,7 @@ static int perf_overcommit __read_mostly = 1;
static atomic_t nr_events __read_mostly;
static atomic_t nr_mmap_events __read_mostly;
+static atomic_t nr_munmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
static atomic_t nr_task_events __read_mostly;
@@ -1891,6 +1892,8 @@ static void free_event(struct perf_event *event)
atomic_dec(&nr_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
+ if (event->attr.munmap)
+ atomic_dec(&nr_munmap_events);
if (event->attr.comm)
atomic_dec(&nr_comm_events);
if (event->attr.task)
@@ -3491,7 +3494,8 @@ perf_event_read_event(struct perf_event *event,
/*
* task tracking -- fork/exit
*
- * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
+ * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.munmap |
+ * attr.task
*/
struct perf_task_event {
@@ -3542,7 +3546,7 @@ static int perf_event_task_match(struct perf_event *event)
return 0;
if (event->attr.comm || event->attr.mmap ||
- event->attr.mmap_data || event->attr.task)
+ event->attr.mmap_data || event->attr.munmap || event->attr.task)
return 1;
return 0;
@@ -3583,6 +3587,7 @@ static void perf_event_task(struct task_struct *task,
if (!atomic_read(&nr_comm_events) &&
!atomic_read(&nr_mmap_events) &&
+ !atomic_read(&nr_munmap_events) &&
!atomic_read(&nr_task_events))
return;
@@ -3776,9 +3781,14 @@ static int perf_event_mmap_match(struct perf_event *event,
if (event->cpu != -1 && event->cpu != smp_processor_id())
return 0;
- if ((!executable && event->attr.mmap_data) ||
- (executable && event->attr.mmap))
+ if (mmap_event->event_id.header.type == PERF_RECORD_MMAP) {
+ if ((!executable && event->attr.mmap_data) ||
+ (executable && event->attr.mmap))
+ return 1;
+ } else if ((mmap_event->event_id.header.type == PERF_RECORD_MUNMAP) &&
+ event->attr.munmap) {
return 1;
+ }
return 0;
}
@@ -3896,6 +3906,35 @@ void perf_event_mmap(struct vm_area_struct *vma)
perf_event_mmap_event(&mmap_event);
}
+void perf_event_munmap(struct vm_area_struct *vma, unsigned long start,
+ size_t len)
+{
+ struct perf_mmap_event mmap_event;
+
+ if (!atomic_read(&nr_munmap_events))
+ return;
+
+ mmap_event = (struct perf_mmap_event){
+ .vma = vma,
+ /* .file_name */
+ /* .file_size */
+ .event_id = {
+ .header = {
+ .type = PERF_RECORD_MUNMAP,
+ .misc = 0,
+ /* .size */
+ },
+ /* .pid */
+ /* .tid */
+ .start = start,
+ .len = len,
+ .pgoff = 0,
+ },
+ };
+
+ perf_event_mmap_event(&mmap_event);
+}
+
/*
* IRQ throttle logging
*/
@@ -4925,6 +4964,8 @@ done:
atomic_inc(&nr_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
+ if (event->attr.munmap)
+ atomic_inc(&nr_munmap_events);
if (event->attr.comm)
atomic_inc(&nr_comm_events);
if (event->attr.task)
diff --git a/mm/mmap.c b/mm/mmap.c
index e38e910..cb03746 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2082,6 +2082,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
}
}
+ perf_event_munmap(vma, start, end - start);
+
/*
* Remove the vma's, and unmap the actual pages
*/
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index b938796..b2018be 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -287,6 +287,7 @@ static void create_counter(int counter, int cpu)
}
attr->mmap = track;
+ attr->munmap = track;
attr->comm = track;
attr->inherit = !no_inherit;
if (target_pid == -1 && target_tid == -1 && !system_wide) {
--
1.7.0.4
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