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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-06-02 15:08:15 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-02 21:45:29 +0200
commit8e5799b1ad2a0567fdfaaf0e91b40efee010f2c1 (patch)
treebd3f45c348f48411a4496229572643211cbd59b8 /kernel/perf_counter.c
parent53e111a730ea8b002d57dd226098c12789993329 (diff)
downloadop-kernel-dev-8e5799b1ad2a0567fdfaaf0e91b40efee010f2c1.zip
op-kernel-dev-8e5799b1ad2a0567fdfaaf0e91b40efee010f2c1.tar.gz
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>
Diffstat (limited to 'kernel/perf_counter.c')
-rw-r--r--kernel/perf_counter.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index caa012c..978ecfc 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1510,6 +1510,8 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
if (counter->hw_event.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
values[n++] = counter->total_time_running +
atomic64_read(&counter->child_total_time_running);
+ if (counter->hw_event.read_format & PERF_FORMAT_ID)
+ values[n++] = counter->id;
mutex_unlock(&counter->child_mutex);
if (count < n * sizeof(u64))
@@ -2303,7 +2305,7 @@ static void perf_counter_output(struct perf_counter *counter,
u32 pid, tid;
} tid_entry;
struct {
- u64 event;
+ u64 id;
u64 counter;
} group_entry;
struct perf_callchain_entry *callchain = NULL;
@@ -2416,7 +2418,7 @@ static void perf_counter_output(struct perf_counter *counter,
if (sub != counter)
sub->pmu->read(sub);
- group_entry.event = sub->hw_event.config;
+ group_entry.id = sub->id;
group_entry.counter = atomic64_read(&sub->count);
perf_output_put(&handle, group_entry);
@@ -3375,6 +3377,8 @@ done:
return counter;
}
+static atomic64_t perf_counter_id;
+
/**
* sys_perf_counter_open - open a performance counter, associate it to a task/cpu
*
@@ -3470,6 +3474,7 @@ SYSCALL_DEFINE5(perf_counter_open,
mutex_unlock(&current->perf_counter_mutex);
counter->ns = get_pid_ns(current->nsproxy->pid_ns);
+ counter->id = atomic64_inc_return(&perf_counter_id);
fput_light(counter_file, fput_needed2);
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