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authorIngo Molnar <mingo@elte.hu>2009-06-03 19:59:24 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-03 20:03:32 +0200
commiteed4dcd443da7a46131ef37c7a389b444905960e (patch)
treef9dfab55e3f14c956ec1d4e3f85487d3258962ef /Documentation
parent44db76c8553c328f4ae02481d77bb3a88ca17645 (diff)
perf report: Add front-entry cache for lookups
Before: Performance counter stats for './perf report -i perf.data.big': 12453988058 instructions Performance counter stats for './perf report -i perf.data.big': 12379566017 instructions 0.60% reduction. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/perf_counter/builtin-report.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index e837bb983dc..33b3b15fb01 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -229,6 +229,7 @@ static int thread__set_comm(struct thread *self, const char *comm)
}
static struct rb_root threads;
+static struct thread *last_match;
static struct thread *threads__findnew(pid_t pid)
{
@@ -236,12 +237,22 @@ static struct thread *threads__findnew(pid_t pid)
struct rb_node *parent = NULL;
struct thread *th;
+ /*
+ * Font-end cache - PID lookups come in blocks,
+ * so most of the time we dont have to look up
+ * the full rbtree:
+ */
+ if (last_match && last_match->pid == pid)
+ return last_match;
+
while (*p != NULL) {
parent = *p;
th = rb_entry(parent, struct thread, rb_node);
- if (th->pid == pid)
+ if (th->pid == pid) {
+ last_match = th;
return th;
+ }
if (pid < th->pid)
p = &(*p)->rb_left;
@@ -253,7 +264,9 @@ static struct thread *threads__findnew(pid_t pid)
if (th != NULL) {
rb_link_node(&th->rb_node, parent, p);
rb_insert_color(&th->rb_node, &threads);
+ last_match = th;
}
+
return th;
}