[PATCH 1/4] bcache: bch_writeback_thread() is not freezable

From: Jiri Kosina
Date: Tue May 24 2016 - 10:38:39 EST


From: Jiri Kosina <jkosina@xxxxxxx>

bch_writeback_thread() is calling try_to_freeze(), but that's just an
expensive no-op given the fact that the thread is not marked freezable.

I/O helper kthreads, exactly such as the bcache writeback thread, actually
shouldn't be freezable, because they are potentially necessary for
finalizing the image write-out.

Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---

This is a resend of a series sent more than a month ago and pinged
multiple time since then.

drivers/md/bcache/writeback.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index b9346cd..6012367 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -12,7 +12,6 @@
#include "writeback.h"

#include <linux/delay.h>
-#include <linux/freezer.h>
#include <linux/kthread.h>
#include <trace/events/bcache.h>

@@ -228,7 +227,6 @@ static void read_dirty(struct cached_dev *dc)
*/

while (!kthread_should_stop()) {
- try_to_freeze();

w = bch_keybuf_next(&dc->writeback_keys);
if (!w)
@@ -433,7 +431,6 @@ static int bch_writeback_thread(void *arg)
if (kthread_should_stop())
return 0;

- try_to_freeze();
schedule();
continue;
}
--
Jiri Kosina
SUSE Labs