Revert "workqueue: Move nr_active handling into helpers"

This reverts commit 4023a2d95076918abe2757d60810642a8115b586 which is
commit 1c270b79ce0b8290f146255ea9057243f6dd3c17 upstream.

The workqueue patches backported to 6.6.y caused some reported
regressions, so revert them for now.

Reported-by: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Tejun Heo <tj@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Audra Mitchell <audra@redhat.com>
Link: https://lore.kernel.org/all/ce4c2f67-c298-48a0-87a3-f933d646c73b@leemhuis.info/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 51dc508ac35b50e8d771ad0b117089b34b481a81..3436fd266cde0881bc31697386493dada19c6d4b 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1458,14 +1458,11 @@ static bool pwq_is_empty(struct pool_workqueue *pwq)
 static void __pwq_activate_work(struct pool_workqueue *pwq,
                                struct work_struct *work)
 {
-       unsigned long *wdb = work_data_bits(work);
-
-       WARN_ON_ONCE(!(*wdb & WORK_STRUCT_INACTIVE));
        trace_workqueue_activate_work(work);
        if (list_empty(&pwq->pool->worklist))
                pwq->pool->watchdog_ts = jiffies;
        move_linked_works(work, &pwq->pool->worklist, NULL);
-       __clear_bit(WORK_STRUCT_INACTIVE_BIT, wdb);
+       __clear_bit(WORK_STRUCT_INACTIVE_BIT, work_data_bits(work));
 }
 
 /**
@@ -1490,66 +1487,12 @@ static bool pwq_activate_work(struct pool_workqueue *pwq,
        return true;
 }
 
-/**
- * pwq_tryinc_nr_active - Try to increment nr_active for a pwq
- * @pwq: pool_workqueue of interest
- *
- * Try to increment nr_active for @pwq. Returns %true if an nr_active count is
- * successfully obtained. %false otherwise.
- */
-static bool pwq_tryinc_nr_active(struct pool_workqueue *pwq)
-{
-       struct workqueue_struct *wq = pwq->wq;
-       struct worker_pool *pool = pwq->pool;
-       bool obtained;
-
-       lockdep_assert_held(&pool->lock);
-
-       obtained = pwq->nr_active < READ_ONCE(wq->max_active);
-
-       if (obtained)
-               pwq->nr_active++;
-       return obtained;
-}
-
-/**
- * pwq_activate_first_inactive - Activate the first inactive work item on a pwq
- * @pwq: pool_workqueue of interest
- *
- * Activate the first inactive work item of @pwq if available and allowed by
- * max_active limit.
- *
- * Returns %true if an inactive work item has been activated. %false if no
- * inactive work item is found or max_active limit is reached.
- */
-static bool pwq_activate_first_inactive(struct pool_workqueue *pwq)
-{
-       struct work_struct *work =
-               list_first_entry_or_null(&pwq->inactive_works,
-                                        struct work_struct, entry);
-
-       if (work && pwq_tryinc_nr_active(pwq)) {
-               __pwq_activate_work(pwq, work);
-               return true;
-       } else {
-               return false;
-       }
-}
-
-/**
- * pwq_dec_nr_active - Retire an active count
- * @pwq: pool_workqueue of interest
- *
- * Decrement @pwq's nr_active and try to activate the first inactive work item.
- */
-static void pwq_dec_nr_active(struct pool_workqueue *pwq)
+static void pwq_activate_first_inactive(struct pool_workqueue *pwq)
 {
-       struct worker_pool *pool = pwq->pool;
+       struct work_struct *work = list_first_entry(&pwq->inactive_works,
+                                                   struct work_struct, entry);
 
-       lockdep_assert_held(&pool->lock);
-
-       pwq->nr_active--;
-       pwq_activate_first_inactive(pwq);
+       pwq_activate_work(pwq, work);
 }
 
 /**
@@ -1567,8 +1510,14 @@ static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, unsigned long work_
 {
        int color = get_work_color(work_data);
 
-       if (!(work_data & WORK_STRUCT_INACTIVE))
-               pwq_dec_nr_active(pwq);
+       if (!(work_data & WORK_STRUCT_INACTIVE)) {
+               pwq->nr_active--;
+               if (!list_empty(&pwq->inactive_works)) {
+                       /* one down, submit an inactive one */
+                       if (pwq->nr_active < READ_ONCE(pwq->wq->max_active))
+                               pwq_activate_first_inactive(pwq);
+               }
+       }
 
        pwq->nr_in_flight[color]--;
 
@@ -1870,11 +1819,13 @@ retry:
         * @work must also queue behind existing inactive work items to maintain
         * ordering when max_active changes. See wq_adjust_max_active().
         */
-       if (list_empty(&pwq->inactive_works) && pwq_tryinc_nr_active(pwq)) {
+       if (list_empty(&pwq->inactive_works) &&
+           pwq->nr_active < READ_ONCE(pwq->wq->max_active)) {
                if (list_empty(&pool->worklist))
                        pool->watchdog_ts = jiffies;
 
                trace_workqueue_activate_work(work);
+               pwq->nr_active++;
                insert_work(pwq, work, &pool->worklist, work_flags);
                kick_pool(pool);
        } else {
@@ -4736,8 +4687,9 @@ static void wq_adjust_max_active(struct workqueue_struct *wq)
                /* this function can be called during early boot w/ irq disabled */
                raw_spin_lock_irqsave(&pwq->pool->lock, flags);
 
-               while (pwq_activate_first_inactive(pwq))
-                       ;
+               while (!list_empty(&pwq->inactive_works) &&
+                      pwq->nr_active < wq->max_active)
+                       pwq_activate_first_inactive(pwq);
 
                kick_pool(pwq->pool);