Dear RT folks!
I'm pleased to announce the v5.6.17-rt9 patch set.
Changes since v5.6.17-rt8:
- Replace the workqueue related patches with those that have been
merged upstream.
- Don't acquire a sleeping lock with disabled interrupts in
bluetooth/rfcomm. Reported by Luis Claudio R. Goncalves.
Known issues
- It has been pointed out that due to changes to the printk code the
internal buffer representation changed. This is only an issue if tools
like `crash' are used to extract the printk buffer from a kernel memory
image.
The delta patch against v5.6.17-rt8 is appended below and can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/incr/patch-5.6.17-rt8-rt9.patch.xz
You can get this release via the git tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
v5.6.17-rt9
The RT patch against v5.6.17 can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/older/patch-5.6.17-rt9.patch.xz
The split quilt queue is available at:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/older/patches-5.6.17-rt9.tar.xz
Sebastian
diff --git a/include/linux/swait.h b/include/linux/swait.h
index 21ae66cd41d30..f426a0661aa03 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -299,18 +299,4 @@ do {
\
__ret; \
})
-#define __swait_event_lock_irq(wq, condition, lock, cmd) \
- ___swait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \
- raw_spin_unlock_irq(&lock); \
- cmd; \
- schedule(); \
- raw_spin_lock_irq(&lock))
-
-#define swait_event_lock_irq(wq_head, condition, lock) \
- do { \
- if (condition) \
- break; \
- __swait_event_lock_irq(wq_head, condition, lock, ); \
- } while (0)
-
#endif /* _LINUX_SWAIT_H */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index a62f326a0b0ad..e958258669972 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -50,7 +50,6 @@
#include <linux/uaccess.h>
#include <linux/sched/isolation.h>
#include <linux/nmi.h>
-#include <linux/swait.h>
#include "workqueue_internal.h"
@@ -302,7 +301,8 @@ static struct workqueue_attrs
*wq_update_unbound_numa_attrs_buf;
static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */
static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */
static DEFINE_RAW_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */
-static DECLARE_SWAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go
away */
+/* wait for manager to go away */
+static struct rcuwait manager_wait = __RCUWAIT_INITIALIZER(manager_wait);
static LIST_HEAD(workqueues); /* PR: list of all workqueues */
static bool workqueue_freezing; /* PL: have wqs started
freezing? */
@@ -1609,11 +1609,9 @@ EXPORT_SYMBOL_GPL(queue_work_node);
void delayed_work_timer_fn(struct timer_list *t)
{
struct delayed_work *dwork = from_timer(dwork, t, timer);
- unsigned long flags;
- local_irq_save(flags);
+ /* should have been called from irqsafe timer with irq already off */
__queue_work(dwork->cpu, dwork->wq, &dwork->work);
- local_irq_restore(flags);
}
EXPORT_SYMBOL(delayed_work_timer_fn);
@@ -2141,7 +2139,7 @@ static bool manage_workers(struct worker *worker)
pool->manager = NULL;
pool->flags &= ~POOL_MANAGER_ACTIVE;
- swake_up_one(&wq_manager_wait);
+ rcuwait_wake_up(&manager_wait);
return true;
}
@@ -3505,6 +3503,18 @@ static void rcu_free_pool(struct rcu_head *rcu)
kfree(pool);
}
+/* This returns with the lock held on success (pool manager is inactive). */
+static bool wq_manager_inactive(struct worker_pool *pool)
+{
+ raw_spin_lock_irq(&pool->lock);
+
+ if (pool->flags & POOL_MANAGER_ACTIVE) {
+ raw_spin_unlock_irq(&pool->lock);
+ return false;
+ }
+ return true;
+}
+
/**
* put_unbound_pool - put a worker_pool
* @pool: worker_pool to put
@@ -3540,10 +3550,10 @@ static void put_unbound_pool(struct worker_pool *pool)
* Become the manager and destroy all workers. This prevents
* @pool's workers from blocking on attach_mutex. We're the last
* manager and @pool gets freed with the flag set.
+ * Because of how wq_manager_inactive() works, we will hold the
+ * spinlock after a successful wait.
*/
- raw_spin_lock_irq(&pool->lock);
- swait_event_lock_irq(wq_manager_wait,
- !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock);
+ rcuwait_wait_event(&manager_wait, wq_manager_inactive(pool));
pool->flags |= POOL_MANAGER_ACTIVE;
while ((worker = first_idle_worker(pool)))
diff --git a/localversion-rt b/localversion-rt
index 700c857efd9ba..22746d6390a42 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt8
+-rt9
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index b4eaf21360ef2..df14eebe80da8 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -64,15 +64,13 @@ static void rfcomm_sk_data_ready(struct rfcomm_dlc *d,
struct sk_buff *skb)
static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
{
struct sock *sk = d->owner, *parent;
- unsigned long flags;
if (!sk)
return;
BT_DBG("dlc %p state %ld err %d", d, d->state, err);
- local_irq_save(flags);
- bh_lock_sock(sk);
+ spin_lock_bh(&sk->sk_lock.slock);
if (err)
sk->sk_err = err;
@@ -93,8 +91,7 @@ static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int
err)
sk->sk_state_change(sk);
}
- bh_unlock_sock(sk);
- local_irq_restore(flags);
+ spin_unlock_bh(&sk->sk_lock.slock);
if (parent && sock_flag(sk, SOCK_ZAPPED)) {
/* We have to drop DLC lock here, otherwise
