gru: collect per-context user statistics

Collect GRU statistics for each user GRU context.  Statistics are kept for
TLB misses & content resource contention.  Add user request for retrieving
the statistics.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index e38a0f1..347004e 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -744,6 +744,7 @@
 	spin_unlock(&blade->bs_lock);
 
 	if (ngts) {
+		gts->ustats.context_stolen++;
 		ngts->ts_steal_jiffies = jiffies;
 		gru_unload_context(ngts, is_kernel_context(ngts) ? 0 : 1);
 		gts_stolen(ngts, blade);