workqueue: prepare for WQ_UNBOUND implementation
In preparation of WQ_UNBOUND addition, make the following changes.
* Add WORK_CPU_* constants for pseudo cpu id numbers used (currently
only WORK_CPU_NONE) and use them instead of NR_CPUS. This is to
allow another pseudo cpu id for unbound cpu.
* Reorder WQ_* flags.
* Make workqueue_struct->cpu_wq a union which contains a percpu
pointer, regular pointer and an unsigned long value and use
kzalloc/kfree() in UP allocation path. This will be used to
implement unbound workqueues which will use only one cwq on SMPs.
* Move alloc_cwqs() allocation after initialization of wq fields, so
that alloc_cwqs() has access to wq->flags.
* Trivial relocation of wq local variables in freeze functions.
These changes don't cause any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 3f36d37..139069a 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -50,6 +50,10 @@
WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
WORK_NO_COLOR = WORK_NR_COLORS,
+ /* special cpu IDs */
+ WORK_CPU_NONE = NR_CPUS,
+ WORK_CPU_LAST = WORK_CPU_NONE,
+
/*
* Reserve 6 bits off of cwq pointer w/ debugobjects turned
* off. This makes cwqs aligned to 64 bytes which isn't too
@@ -60,7 +64,7 @@
WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
- WORK_STRUCT_NO_CPU = NR_CPUS << WORK_STRUCT_FLAG_BITS,
+ WORK_STRUCT_NO_CPU = WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS,
/* bit mask for work_busy() return values */
WORK_BUSY_PENDING = 1 << 0,
@@ -227,9 +231,9 @@
clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
enum {
- WQ_FREEZEABLE = 1 << 0, /* freeze during suspend */
+ WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
WQ_SINGLE_CPU = 1 << 1, /* only single cpu at a time */
- WQ_NON_REENTRANT = 1 << 2, /* guarantee non-reentrance */
+ WQ_FREEZEABLE = 1 << 2, /* freeze during suspend */
WQ_RESCUER = 1 << 3, /* has an rescue worker */
WQ_HIGHPRI = 1 << 4, /* high priority */
WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */