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authorArnaldo Carvalho de Melo <acme@redhat.com>2010-06-17 08:37:44 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2010-06-17 08:37:44 -0300
commit720a3aeb7373cb49cf222d5f12e121f78d3d4410 (patch)
treee2451f06fe4983c4aae971bdaf31fe538a7fec1a
parent174787cb5144e5a45141ec7cb9d95ea29bbe22bb (diff)
downloadop-kernel-dev-720a3aeb7373cb49cf222d5f12e121f78d3d4410.zip
op-kernel-dev-720a3aeb7373cb49cf222d5f12e121f78d3d4410.tar.gz
perf session: Remove threads from tree on PERF_RECORD_EXIT
Move them to a session->dead_threads list just like we do with maps that are replaced, because we may have hist_entries pointing to them. This fixes a bug when inserting maps for a new thread that reused the TID, mixing maps for two different threads, causing an endless loop. The code for insering maps should be made more robust but for .35 this is the minimalistic patch. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: David S. Miller <davem@davemloft.net> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/util/event.c4
-rw-r--r--tools/perf/util/session.c11
-rw-r--r--tools/perf/util/session.h2
-rw-r--r--tools/perf/util/thread.h5
4 files changed, 20 insertions, 2 deletions
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 1f08f00..2fbf6a4 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -538,8 +538,10 @@ int event__process_task(event_t *self, struct perf_session *session)
dump_printf("(%d:%d):(%d:%d)\n", self->fork.pid, self->fork.tid,
self->fork.ppid, self->fork.ptid);
- if (self->header.type == PERF_RECORD_EXIT)
+ if (self->header.type == PERF_RECORD_EXIT) {
+ perf_session__remove_thread(session, thread);
return 0;
+ }
if (thread == NULL || parent == NULL ||
thread__fork(thread, parent) < 0) {
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 8f83a18..c422cd6 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -90,6 +90,7 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
memcpy(self->filename, filename, len);
self->threads = RB_ROOT;
+ INIT_LIST_HEAD(&self->dead_threads);
self->hists_tree = RB_ROOT;
self->last_match = NULL;
self->mmap_window = 32;
@@ -131,6 +132,16 @@ void perf_session__delete(struct perf_session *self)
free(self);
}
+void perf_session__remove_thread(struct perf_session *self, struct thread *th)
+{
+ rb_erase(&th->rb_node, &self->threads);
+ /*
+ * We may have references to this thread, for instance in some hist_entry
+ * instances, so just move them to a separate list.
+ */
+ list_add_tail(&th->node, &self->dead_threads);
+}
+
static bool symbol__match_parent_regex(struct symbol *sym)
{
if (sym->name && !regexec(&parent_regex, sym->name, 0, NULL, 0))
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 55c6881..9fa0fc2 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -26,6 +26,7 @@ struct perf_session {
unsigned long size;
unsigned long mmap_window;
struct rb_root threads;
+ struct list_head dead_threads;
struct thread *last_match;
struct machine host_machine;
struct rb_root machines;
@@ -99,6 +100,7 @@ int perf_session__create_kernel_maps(struct perf_session *self);
int do_read(int fd, void *buf, size_t size);
void perf_session__update_sample_type(struct perf_session *self);
+void perf_session__remove_thread(struct perf_session *self, struct thread *th);
static inline
struct machine *perf_session__find_host_machine(struct perf_session *self)
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 1dfd9ff..ee6bbcf 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -6,7 +6,10 @@
#include "symbol.h"
struct thread {
- struct rb_node rb_node;
+ union {
+ struct rb_node rb_node;
+ struct list_head node;
+ };
struct map_groups mg;
pid_t pid;
char shortname[3];
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