From 8719dceae2f98a578507c0f6b49c93f320bd729c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 12 Mar 2013 11:30:04 -0700 Subject: workqueue: reject adjusting max_active or applying attrs to ordered workqueues Adjusting max_active of or applying new workqueue_attrs to an ordered workqueue breaks its ordering guarantee. The former is obvious. The latter is because applying attrs creates a new pwq (pool_workqueue) and there is no ordering constraint between the old and new pwqs. Make apply_workqueue_attrs() and workqueue_set_max_active() trigger WARN_ON() if those operations are requested on an ordered workqueue and fail / ignore respectively. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan --- include/linux/workqueue.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/workqueue.h') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 1751ec4c47c9..5668ab249af5 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -295,6 +295,7 @@ enum { WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */ __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ + __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ @@ -397,7 +398,7 @@ __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 | (flags), 1, ##args) + alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args) #define create_workqueue(name) \ alloc_workqueue((name), WQ_MEM_RECLAIM, 1) -- cgit v1.2.3