This is a note to let you know that I've just added the patch titled
bcache: Make gc wakeup sane, remove set_task_state()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bcache-make-gc-wakeup-sane-remove-set_task_state.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From be628be09563f8f6e81929efbd7cf3f45c344416 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Date: Wed, 26 Oct 2016 20:31:17 -0700
Subject: bcache: Make gc wakeup sane, remove set_task_state()
From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
commit be628be09563f8f6e81929efbd7cf3f45c344416 upstream.
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Coly Li <colyli@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/bcache/bcache.h | 4 ++--
drivers/md/bcache/btree.c | 39 ++++++++++++++++++++-------------------
drivers/md/bcache/btree.h | 3 +--
drivers/md/bcache/request.c | 4 +---
drivers/md/bcache/super.c | 2 ++
5 files changed, 26 insertions(+), 26 deletions(-)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -425,7 +425,7 @@ struct cache {
* until a gc finishes - otherwise we could pointlessly burn a ton of
* cpu
*/
- unsigned invalidate_needs_gc:1;
+ unsigned invalidate_needs_gc;
bool discard; /* Get rid of? */
@@ -593,8 +593,8 @@ struct cache_set {
/* Counts how many sectors bio_insert has added to the cache */
atomic_t sectors_to_gc;
+ wait_queue_head_t gc_wait;
- wait_queue_head_t moving_gc_wait;
struct keybuf moving_gc_keys;
/* Number of moving GC bios in flight */
struct semaphore moving_in_flight;
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1757,32 +1757,34 @@ static void bch_btree_gc(struct cache_se
bch_moving_gc(c);
}
-static int bch_gc_thread(void *arg)
+static bool gc_should_run(struct cache_set *c)
{
- struct cache_set *c = arg;
struct cache *ca;
unsigned i;
- while (1) {
-again:
- bch_btree_gc(c);
+ for_each_cache(ca, c, i)
+ if (ca->invalidate_needs_gc)
+ return true;
- set_current_state(TASK_INTERRUPTIBLE);
- if (kthread_should_stop())
- break;
+ if (atomic_read(&c->sectors_to_gc) < 0)
+ return true;
- mutex_lock(&c->bucket_lock);
+ return false;
+}
- for_each_cache(ca, c, i)
- if (ca->invalidate_needs_gc) {
- mutex_unlock(&c->bucket_lock);
- set_current_state(TASK_RUNNING);
- goto again;
- }
+static int bch_gc_thread(void *arg)
+{
+ struct cache_set *c = arg;
- mutex_unlock(&c->bucket_lock);
+ while (1) {
+ wait_event_interruptible(c->gc_wait,
+ kthread_should_stop() || gc_should_run(c));
- schedule();
+ if (kthread_should_stop())
+ break;
+
+ set_gc_sectors(c);
+ bch_btree_gc(c);
}
return 0;
@@ -1790,11 +1792,10 @@ again:
int bch_gc_thread_start(struct cache_set *c)
{
- c->gc_thread = kthread_create(bch_gc_thread, c, "bcache_gc");
+ c->gc_thread = kthread_run(bch_gc_thread, c, "bcache_gc");
if (IS_ERR(c->gc_thread))
return PTR_ERR(c->gc_thread);
- set_task_state(c->gc_thread, TASK_INTERRUPTIBLE);
return 0;
}
--- a/drivers/md/bcache/btree.h
+++ b/drivers/md/bcache/btree.h
@@ -260,8 +260,7 @@ void bch_initial_mark_key(struct cache_s
static inline void wake_up_gc(struct cache_set *c)
{
- if (c->gc_thread)
- wake_up_process(c->gc_thread);
+ wake_up(&c->gc_wait);
}
#define MAP_DONE 0
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -196,10 +196,8 @@ static void bch_data_insert_start(struct
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
struct bio *bio = op->bio, *n;
- if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) {
- set_gc_sectors(op->c);
+ if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0)
wake_up_gc(op->c);
- }
if (op->bypass)
return bch_data_invalidate(cl);
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1491,6 +1491,7 @@ struct cache_set *bch_cache_set_alloc(st
mutex_init(&c->bucket_lock);
init_waitqueue_head(&c->btree_cache_wait);
init_waitqueue_head(&c->bucket_wait);
+ init_waitqueue_head(&c->gc_wait);
sema_init(&c->uuid_write_mutex, 1);
spin_lock_init(&c->btree_gc_time.lock);
@@ -1550,6 +1551,7 @@ static void run_cache_set(struct cache_s
for_each_cache(ca, c, i)
c->nbuckets += ca->sb.nbuckets;
+ set_gc_sectors(c);
if (CACHE_SYNC(&c->sb)) {
LIST_HEAD(journal);
Patches currently in stable-queue which might be from kent.overstreet@xxxxxxxxx are
queue-4.9/bcache-make-gc-wakeup-sane-remove-set_task_state.patch