perf report: Add front-entry cache for lookups (eed4dcd4) · Commits · 戴 / test

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>

Documentation/perf_counter/builtin-report.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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