perf_counter: Change pctrl() behaviour

Instead of en/dis-abling all counters acting on a particular
task, en/dis- able all counters we created.

[ v2: fix crash on first counter enable ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.916937244@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index d87247d2641f..353c0ac7723a 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -108,6 +108,15 @@ extern struct group_info init_groups;
 
 extern struct cred init_cred;
 
+#ifdef CONFIG_PERF_COUNTERS
+# define INIT_PERF_COUNTERS(tsk)                                        \
+        .perf_counter_mutex =                                           \
+                 __MUTEX_INITIALIZER(tsk.perf_counter_mutex),           \
+        .perf_counter_list = LIST_HEAD_INIT(tsk.perf_counter_list),
+#else
+# define INIT_PERF_COUNTERS(tsk)
+#endif
+
 /*
  *  INIT_TASK is used to set up the first task table, touch at
  * your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -171,6 +180,7 @@ extern struct cred init_cred;
         },                                                              \
         .dirties = INIT_PROP_LOCAL_SINGLE(dirties),                     \
         INIT_IDS                                                        \
+        INIT_PERF_COUNTERS(tsk)                                         \
         INIT_TRACE_IRQFLAGS                                             \
         INIT_LOCKDEP                                                    \
         INIT_FTRACE_GRAPH                                               \