crypto: disable preemption while benchmarking RAID5 xor checksumming

With CONFIG_PREEMPT=y, we need to disable preemption while benchmarking RAID5 xor checksumming to ensure we're actually measuring what we think we're measuring. Signed-off-by: Jim Kukunas <[email protected]> Signed-off-by: NeilBrown <[email protected]>
rtvt123 · May 22, 2012 · 56a5199 · 56a5199
1 parent 6a32847
commit 56a5199
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/crypto/xor.c b/crypto/xor.c
@@ -21,6 +21,7 @@
 #include <linux/gfp.h>
 #include <linux/raid/xor.h>
 #include <linux/jiffies.h>
+#include <linux/preempt.h>
 #include <asm/xor.h>
 
 /* The xor routines to use.  */
@@ -69,6 +70,8 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
 	tmpl->next = template_list;
 	template_list = tmpl;
 
+	preempt_disable();
+
 	/*
 	 * Count the number of XORs done during a whole jiffy, and use
 	 * this to calculate the speed of checksumming.  We use a 2-page
@@ -91,6 +94,8 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
 			max = count;
 	}
 
+	preempt_enable();
+
 	speed = max * (HZ * BENCH_SIZE / 1024);
 	tmpl->speed = speed;