From 17b02695b254aa2ef0e53df9c8e6548f86e66a9d Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Sat, 28 Oct 2006 10:38:52 -0700
Subject: [PATCH] [PATCH] taskstats_tgid_alloc: optimization

Every subthread (except first) does unneeded kmem_cache_alloc/kmem_cache_free.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 include/linux/taskstats_kern.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/taskstats_kern.h b/include/linux/taskstats_kern.h
index a437ca0d226b..664224008fb2 100644
--- a/include/linux/taskstats_kern.h
+++ b/include/linux/taskstats_kern.h
@@ -32,6 +32,9 @@ static inline void taskstats_tgid_alloc(struct signal_struct *sig)
 	struct taskstats *stats;
 	unsigned long flags;
 
+	if (sig->stats != NULL)
+		return;
+
 	stats = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL);
 	if (!stats)
 		return;
-- 
2.20.1