From 720a3aeb7373cb49cf222d5f12e121f78d3d4410 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 17 Jun 2010 08:37:44 -0300 Subject: [PATCH] perf session: Remove threads from tree on PERF_RECORD_EXIT MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: David S. Miller Cc: Frédéric Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tom Zanussi LKML-Reference: Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.c | 4 +++- tools/perf/util/session.c | 11 +++++++++++ tools/perf/util/session.h | 2 ++ tools/perf/util/thread.h | 5 ++++- 4 files changed, 20 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 1f08f008d289..2fbf6a463c81 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 8f83a1835766..c422cd676313 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 55c6881b218d..9fa0fc2a863f 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 1dfd9ff8bdcd..ee6bbcf277ca 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]; -- 2.20.1