[PATCH v2 1/3] virtio-rng cleanup: move some code out of mutex protection

Amos Kong
Mon, 15 Sep 2014 16:02:27 -0000

It doesn't save too much cpu time as expected, just a cleanup.

Signed-off-by: Amos Kong <akong at redhat.com>
---
 drivers/char/hw_random/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index aa30a25..c591d7e 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -270,8 +270,8 @@ static ssize_t hwrng_attr_current_show(struct device *dev,
 		return -ERESTARTSYS;
 	if (current_rng)
 		name = current_rng->name;
-	ret = snprintf(buf, PAGE_SIZE, "%s\n", name);
 	mutex_unlock(&rng_mutex);
+	ret = snprintf(buf, PAGE_SIZE, "%s\n", name);

 	return ret;
 }
@@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device
*dev,
 	ssize_t ret = 0;
 	struct hwrng *rng;

+	buf[0] = '\0';
 	err = mutex_lock_interruptible(&rng_mutex);
 	if (err)
 		return -ERESTARTSYS;
-	buf[0] = '\0';
 	list_for_each_entry(rng, &rng_list, list) {
 		strncat(buf, rng->name, PAGE_SIZE - ret - 1);
 		ret += strlen(rng->name);
 		strncat(buf, " ", PAGE_SIZE - ret - 1);
 		ret++;
 	}
+	mutex_unlock(&rng_mutex);
 	strncat(buf, "\n", PAGE_SIZE - ret - 1);
 	ret++;
-	mutex_unlock(&rng_mutex);

 	return ret;
 }
--
1.9.3