From: Benjamin Marzinski <bmarzins@redhat.com>
To: Mikulas Patocka <mpatocka@redhat.com>,
Mike Snitzer <snitzer@kernel.org>,
Heinz Mauelshagen <mauelshagen@redhat.com>
Cc: dm-devel@lists.linux.dev
Subject: [PATCH 3/3] dm-delay: remove timer_lock
Date: Tue, 7 May 2024 17:16:25 -0400 [thread overview]
Message-ID: <20240507211626.26706-4-bmarzins@redhat.com> (raw)
In-Reply-To: <20240507211626.26706-1-bmarzins@redhat.com>
Instead of manually checking the timer details in queue_timeout(), call
timer_reduce() to start the timer or reduce the expiration time. This
avoids needing a lock.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
drivers/md/dm-delay.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index b1829c106a37..297ae7ffcd0b 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -28,7 +28,6 @@ struct delay_class {
struct delay_c {
struct timer_list delay_timer;
- struct mutex timer_lock;
struct mutex process_bios_lock; /* hold while removing bios to be processed from list */
spinlock_t delayed_bios_lock; /* hold on all accesses to delayed_bios list */
struct workqueue_struct *kdelayd_wq;
@@ -60,12 +59,7 @@ static void handle_delayed_timer(struct timer_list *t)
static void queue_timeout(struct delay_c *dc, unsigned long expires)
{
- mutex_lock(&dc->timer_lock);
-
- if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires)
- mod_timer(&dc->delay_timer, expires);
-
- mutex_unlock(&dc->timer_lock);
+ timer_reduce(&dc->delay_timer, expires);
}
static inline bool delay_is_fast(struct delay_c *dc)
@@ -176,7 +170,6 @@ static void delay_dtr(struct dm_target *ti)
kthread_stop(dc->worker);
mutex_destroy(&dc->process_bios_lock);
- mutex_destroy(&dc->timer_lock);
kfree(dc);
}
@@ -234,7 +227,6 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->private = dc;
INIT_LIST_HEAD(&dc->delayed_bios);
- mutex_init(&dc->timer_lock);
mutex_init(&dc->process_bios_lock);
spin_lock_init(&dc->delayed_bios_lock);
dc->may_delay = true;
--
2.45.0
next prev parent reply other threads:[~2024-05-07 21:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 21:16 [PATCH 0/3] dm-delay synchronization cleanup Benjamin Marzinski
2024-05-07 21:16 ` [PATCH 1/3] dm-delay: fix workqueue delay_timer race Benjamin Marzinski
2024-05-07 21:16 ` [PATCH 2/3] dm-delay: change locking to avoid contention Benjamin Marzinski
2024-05-07 21:16 ` Benjamin Marzinski [this message]
2024-05-09 14:24 ` [PATCH 0/3] dm-delay synchronization cleanup Mike Snitzer
2024-05-09 16:07 ` Benjamin Marzinski
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