From 8e5799b1ad2a0567fdfaaf0e91b40efee010f2c1 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue, 2 Jun 2009 15:08:15 +0200
Subject: perf_counter: Add unique counter id

Stephan raised the issue that we currently cannot distinguish between
similar counters within a group (PERF_RECORD_GROUP uses the config
value as identifier).

Therefore, generate a new ID for each counter using a global u64
sequence counter.

Reported-by: Stephane Eranian <eranian@googlemail.com>
Signed-off-by: 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>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/linux/perf_counter.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'include')

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 9ec20fc6bd3..4845a214b9e 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -114,8 +114,9 @@ enum perf_counter_record_format {
  * in increasing order of bit value, after the counter value.
  */
 enum perf_counter_read_format {
-	PERF_FORMAT_TOTAL_TIME_ENABLED	=  1,
-	PERF_FORMAT_TOTAL_TIME_RUNNING	=  2,
+	PERF_FORMAT_TOTAL_TIME_ENABLED	=  1U << 0,
+	PERF_FORMAT_TOTAL_TIME_RUNNING	=  1U << 1,
+	PERF_FORMAT_ID			=  1U << 2,
 };
 
 /*
@@ -290,7 +291,7 @@ enum perf_event_type {
 	 *	{ u32			cpu, res; } && PERF_RECORD_CPU
 	 *
 	 *	{ u64			nr;
-	 *	  { u64 event, val; }	cnt[nr];  } && PERF_RECORD_GROUP
+	 *	  { u64 id, val; }	cnt[nr];  } && PERF_RECORD_GROUP
 	 *
 	 *	{ u16			nr,
 	 *				hv,
@@ -503,6 +504,7 @@ struct perf_counter {
 	struct rcu_head			rcu_head;
 
 	struct pid_namespace		*ns;
+	u64				id;
 #endif
 };
 
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