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-rw-r--r--tools/include/uapi/linux/perf_event.h2
-rw-r--r--tools/perf/util/event.c1
-rw-r--r--tools/perf/util/machine.c19
-rw-r--r--tools/perf/util/thread.c13
-rw-r--r--tools/perf/util/thread.h2
5 files changed, 27 insertions, 10 deletions
diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index f35eb72739c0..9de8780ac8d9 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -646,10 +646,12 @@ struct perf_event_mmap_page {
*
* PERF_RECORD_MISC_MMAP_DATA - PERF_RECORD_MMAP* events
* PERF_RECORD_MISC_COMM_EXEC - PERF_RECORD_COMM event
+ * PERF_RECORD_MISC_FORK_EXEC - PERF_RECORD_FORK event (perf internal)
* PERF_RECORD_MISC_SWITCH_OUT - PERF_RECORD_SWITCH* events
*/
#define PERF_RECORD_MISC_MMAP_DATA (1 << 13)
#define PERF_RECORD_MISC_COMM_EXEC (1 << 13)
+#define PERF_RECORD_MISC_FORK_EXEC (1 << 13)
#define PERF_RECORD_MISC_SWITCH_OUT (1 << 13)
/*
* These PERF_RECORD_MISC_* flags below are safely reused
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index bc646185f8d9..e9c108a6b1c3 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -308,6 +308,7 @@ static int perf_event__synthesize_fork(struct perf_tool *tool,
event->fork.pid = tgid;
event->fork.tid = pid;
event->fork.header.type = PERF_RECORD_FORK;
+ event->fork.header.misc = PERF_RECORD_MISC_FORK_EXEC;
event->fork.header.size = (sizeof(event->fork) + machine->id_hdr_size);
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 8ee8ab39d8ac..8f36ce813bc5 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1708,6 +1708,7 @@ int machine__process_fork_event(struct machine *machine, union perf_event *event
struct thread *parent = machine__findnew_thread(machine,
event->fork.ppid,
event->fork.ptid);
+ bool do_maps_clone = true;
int err = 0;
if (dump_trace)
@@ -1736,9 +1737,25 @@ int machine__process_fork_event(struct machine *machine, union perf_event *event
thread = machine__findnew_thread(machine, event->fork.pid,
event->fork.tid);
+ /*
+ * When synthesizing FORK events, we are trying to create thread
+ * objects for the already running tasks on the machine.
+ *
+ * Normally, for a kernel FORK event, we want to clone the parent's
+ * maps because that is what the kernel just did.
+ *
+ * But when synthesizing, this should not be done. If we do, we end up
+ * with overlapping maps as we process the sythesized MMAP2 events that
+ * get delivered shortly thereafter.
+ *
+ * Use the FORK event misc flags in an internal way to signal this
+ * situation, so we can elide the map clone when appropriate.
+ */
+ if (event->fork.header.misc & PERF_RECORD_MISC_FORK_EXEC)
+ do_maps_clone = false;
if (thread == NULL || parent == NULL ||
- thread__fork(thread, parent, sample->time) < 0) {
+ thread__fork(thread, parent, sample->time, do_maps_clone) < 0) {
dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
err = -1;
}
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 2048d393ece6..3d9ed7d0e281 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -330,7 +330,8 @@ static int thread__prepare_access(struct thread *thread)
}
static int thread__clone_map_groups(struct thread *thread,
- struct thread *parent)
+ struct thread *parent,
+ bool do_maps_clone)
{
/* This is new thread, we share map groups for process. */
if (thread->pid_ == parent->pid_)
@@ -341,15 +342,11 @@ static int thread__clone_map_groups(struct thread *thread,
thread->pid_, thread->tid, parent->pid_, parent->tid);
return 0;
}
-
/* But this one is new process, copy maps. */
- if (map_groups__clone(thread, parent->mg) < 0)
- return -ENOMEM;
-
- return 0;
+ return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0;
}
-int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
+int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
{
if (parent->comm_set) {
const char *comm = thread__comm_str(parent);
@@ -362,7 +359,7 @@ int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
}
thread->ppid = parent->tid;
- return thread__clone_map_groups(thread, parent);
+ return thread__clone_map_groups(thread, parent, do_maps_clone);
}
void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 36c09a9904e6..30e2b4c165fe 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -89,7 +89,7 @@ struct comm *thread__comm(const struct thread *thread);
struct comm *thread__exec_comm(const struct thread *thread);
const char *thread__comm_str(const struct thread *thread);
int thread__insert_map(struct thread *thread, struct map *map);
-int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp);
+int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone);
size_t thread__fprintf(struct thread *thread, FILE *fp);
struct thread *thread__main_thread(struct machine *machine, struct thread *thread);