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| author | Tejun Heo <tj@kernel.org> | 2017-07-23 08:36:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-11 09:09:00 -0700 |
| commit | 34a08ae493f1970d5ce80dd3812b8dba4e5cbe22 (patch) | |
| tree | 02f5cecfb03f2d71e6df69022bd05a5e7edea845 | |
| parent | 0c787041504edd1739a5f8bd04bdd36b8fcb093c (diff) | |
| download | linux-stable-34a08ae493f1970d5ce80dd3812b8dba4e5cbe22.tar.gz linux-stable-34a08ae493f1970d5ce80dd3812b8dba4e5cbe22.tar.bz2 linux-stable-34a08ae493f1970d5ce80dd3812b8dba4e5cbe22.zip | |
workqueue: implicit ordered attribute should be overridable
commit 0a94efb5acbb6980d7c9ab604372d93cd507e4d8 upstream.
5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be
ordered") automatically enabled ordered attribute for unbound
workqueues w/ max_active == 1. Because ordered workqueues reject
max_active and some attribute changes, this implicit ordered mode
broke cases where the user creates an unbound workqueue w/ max_active
== 1 and later explicitly changes the related attributes.
This patch distinguishes explicit and implicit ordered setting and
overrides from attribute changes if implict.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
Cc: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/workqueue.h | 4 | ||||
| -rw-r--r-- | kernel/workqueue.c | 13 |
2 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 0197358f1e81..262d5c95dfc8 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -311,6 +311,7 @@ enum { __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ + __WQ_ORDERED_EXPLICIT = 1 << 18, /* internal: alloc_ordered_workqueue() */ WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ @@ -408,7 +409,8 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, * Pointer to the allocated workqueue on success, %NULL on failure. */ #define alloc_ordered_workqueue(fmt, flags, args...) \ - alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args) + alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \ + __WQ_ORDERED_EXPLICIT | (flags), 1, ##args) #define create_workqueue(name) \ alloc_workqueue("%s", WQ_MEM_RECLAIM, 1, (name)) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 137332379ed4..23231237f2e2 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3647,8 +3647,12 @@ static int apply_workqueue_attrs_locked(struct workqueue_struct *wq, return -EINVAL; /* creating multiple pwqs breaks ordering guarantee */ - if (WARN_ON((wq->flags & __WQ_ORDERED) && !list_empty(&wq->pwqs))) - return -EINVAL; + if (!list_empty(&wq->pwqs)) { + if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT)) + return -EINVAL; + + wq->flags &= ~__WQ_ORDERED; + } ctx = apply_wqattrs_prepare(wq, attrs); @@ -4032,13 +4036,14 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) struct pool_workqueue *pwq; /* disallow meddling with max_active for ordered workqueues */ - if (WARN_ON(wq->flags & __WQ_ORDERED)) + if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT)) return; max_active = wq_clamp_max_active(max_active, wq->flags, wq->name); mutex_lock(&wq->mutex); + wq->flags &= ~__WQ_ORDERED; wq->saved_max_active = max_active; for_each_pwq(pwq, wq) @@ -5164,7 +5169,7 @@ int workqueue_sysfs_register(struct workqueue_struct *wq) * attributes breaks ordering guarantee. Disallow exposing ordered * workqueues. */ - if (WARN_ON(wq->flags & __WQ_ORDERED)) + if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT)) return -EINVAL; wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL); |