perf_counter: Use PID namespaces properly

Stop using task_struct::pid and start using PID namespaces.

PIDs will be reported in the PID namespace of the monitoring
task at the moment of counter creation.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
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>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index d970fbc16afd..9ec20fc6bd36 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -317,6 +317,7 @@ enum perf_event_type {
 #include <linux/spinlock.h>
 #include <linux/hrtimer.h>
 #include <linux/fs.h>
+#include <linux/pid_namespace.h>
 #include <asm/atomic.h>
 
 struct task_struct;
@@ -500,6 +501,8 @@ struct perf_counter {
 
         void (*destroy)(struct perf_counter *);
         struct rcu_head                 rcu_head;
+
+        struct pid_namespace            *ns;
 #endif
 };