perf callchain: Make callchain cursors TLS

perf top -G has a race on callchain cursor between main thread and
display thread. Since the callchain cursors are used locally make them
thread-local data would solve the problem.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Reported-by: Sunjin Yang <fan4326@gmail.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sunjin Yang <fan4326@gmail.com>
Link: http://lkml.kernel.org/r/1338443007-24857-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 2400e009f149b9017ee1d0ad7345092f3bcec46f..25249f76329daf851f925240f8c295c0c3fc5bdc 100644 (file)
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -152,7 +152,7 @@ static int perf_evsel__add_hist_entry(struct perf_evsel *evsel,
 
        if (symbol_conf.use_callchain) {
                err = callchain_append(he->callchain,
-                                      &evsel->hists.callchain_cursor,
+                                      &callchain_cursor,
                                       sample->period);
                if (err)
                        return err;

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 871b540293e132610bb6a50bb384289d89aca75c..6bb0277b7dfecdbf63e727592995480a409f16f5 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -787,7 +787,7 @@ static void perf_event__process_sample(struct perf_tool *tool,
                }
 
                if (symbol_conf.use_callchain) {
-                       err = callchain_append(he->callchain, &evsel->hists.callchain_cursor,
+                       err = callchain_append(he->callchain, &callchain_cursor,
                                               sample->period);
                        if (err)
                                return;

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 9f7106a8d9a48cb6f9600beac10bfa3a38bd9be5..3a6bff47614f788eae96a6ea7c7ed64759ec465a 100644 (file)
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -18,6 +18,8 @@
 #include "util.h"
 #include "callchain.h"
 
+__thread struct callchain_cursor callchain_cursor;
+
 bool ip_callchain__valid(struct ip_callchain *chain,
                         const union perf_event *event)
 {

diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 7f9c0f1ae3a9aad6f6a845299f74d1340ece754f..3bdb407f9cd9f8b9ed9e6340316c4e8237942f5c 100644 (file)
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -76,6 +76,8 @@ struct callchain_cursor {
        struct callchain_cursor_node    *curr;
 };
 
+extern __thread struct callchain_cursor callchain_cursor;
+
 static inline void callchain_init(struct callchain_root *root)
 {
        INIT_LIST_HEAD(&root->node.siblings);

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 1293b5ebea4dd31327a9e36402577779ec41626b..514e2a4b367d6d53838d9ac726a063b0ba3bf5e8 100644 (file)
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -378,7 +378,7 @@ void hist_entry__free(struct hist_entry *he)
  * collapse the histogram
  */
 
-static bool hists__collapse_insert_entry(struct hists *hists,
+static bool hists__collapse_insert_entry(struct hists *hists __used,
                                         struct rb_root *root,
                                         struct hist_entry *he)
 {
@@ -397,8 +397,9 @@ static bool hists__collapse_insert_entry(struct hists *hists,
                        iter->period += he->period;
                        iter->nr_events += he->nr_events;
                        if (symbol_conf.use_callchain) {
-                               callchain_cursor_reset(&hists->callchain_cursor);
-                               callchain_merge(&hists->callchain_cursor, iter->callchain,
+                               callchain_cursor_reset(&callchain_cursor);
+                               callchain_merge(&callchain_cursor,
+                                               iter->callchain,
                                                he->callchain);
                        }
                        hist_entry__free(he);

diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index cfc64e293f90b6f3e065d42379da8bb00302616b..34bb556d62191a1300b295011be6210f9633fcf7 100644 (file)
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -67,8 +67,6 @@ struct hists {
        struct events_stats     stats;
        u64                     event_stream;
        u16                     col_len[HISTC_NR_COLS];
-       /* Best would be to reuse the session callchain cursor */
-       struct callchain_cursor callchain_cursor;
 };
 
 struct hist_entry *__hists__add_entry(struct hists *self,

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 48206144758ef77475a6357e6a0ae272daea9dab..3b6f8e460a316297731106c1ac8169f8af6f8f52 100644 (file)
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -288,7 +288,8 @@ struct branch_info *machine__resolve_bstack(struct machine *self,
        return bi;
 }
 
-int machine__resolve_callchain(struct machine *self, struct perf_evsel *evsel,
+int machine__resolve_callchain(struct machine *self,
+                              struct perf_evsel *evsel __used,
                               struct thread *thread,
                               struct ip_callchain *chain,
                               struct symbol **parent)
@@ -297,7 +298,7 @@ int machine__resolve_callchain(struct machine *self, struct perf_evsel *evsel,
        unsigned int i;
        int err;
 
-       callchain_cursor_reset(&evsel->hists.callchain_cursor);
+       callchain_cursor_reset(&callchain_cursor);
 
        for (i = 0; i < chain->nr; i++) {
                u64 ip;
@@ -333,7 +334,7 @@ int machine__resolve_callchain(struct machine *self, struct perf_evsel *evsel,
                                break;
                }
 
-               err = callchain_cursor_append(&evsel->hists.callchain_cursor,
+               err = callchain_cursor_append(&callchain_cursor,
                                              ip, al.map, al.sym);
                if (err)
                        return err;
@@ -1428,7 +1429,6 @@ void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
                          int print_sym, int print_dso, int print_symoffset)
 {
        struct addr_location al;
-       struct callchain_cursor *cursor = &evsel->hists.callchain_cursor;
        struct callchain_cursor_node *node;
 
        if (perf_event__preprocess_sample(event, machine, &al, sample,
@@ -1446,10 +1446,10 @@ void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
                                error("Failed to resolve callchain. Skipping\n");
                        return;
                }
-               callchain_cursor_commit(cursor);
+               callchain_cursor_commit(&callchain_cursor);
 
                while (1) {
-                       node = callchain_cursor_current(cursor);
+                       node = callchain_cursor_current(&callchain_cursor);
                        if (!node)
                                break;
 
@@ -1465,7 +1465,7 @@ void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
                        }
                        printf("\n");
 
-                       callchain_cursor_advance(cursor);
+                       callchain_cursor_advance(&callchain_cursor);
                }
 
        } else {