Documentation/core-api/workqueue.rst

33 thread system-wide.  A single MT wq needed to keep around the same
43 while an ST wq one for the whole system.  Work items had to compete for
60 * Use per-CPU unified worker pools shared by all wq to provide
83 called worker-pools.
85 The cmwq design differentiates between the user-facing workqueues that
87 which manages worker-pools and processes the queued work items.
89 There are two worker-pools, one for normal work items and the other
91 worker-pools to serve work items queued on unbound workqueues - the
102 When a work item is queued to a workqueue, the target worker-pool is
104 and appended on the shared worklist of the worker-pool.  For example,
106 be queued on the worklist of either normal or highpri worker-pool that
112 Minimal to save resources and sufficient in that the system is used at
115 Each worker-pool bound to an actual CPU implements concurrency
116 management by hooking into the scheduler.  The worker-pool is notified
122 workers on the CPU, the worker-pool doesn't start execution of a new
144 wq's that have a rescue-worker reserved for execution under memory
145 pressure.  Else it is possible that the worker-pool deadlocks waiting
154 removal.  ``alloc_workqueue()`` takes three arguments - ``@name``,
165 ---------
169   worker-pools which host workers which are not bound to any
172   worker-pools try to start execution of work items as soon as
176   * Wide fluctuation in the concurrency level requirement is
182     managed by the system scheduler.
185   A freezable wq participates in the freeze phase of the system
196   worker-pool of the target cpu.  Highpri worker-pools are
199   Note that normal and highpri worker-pools don't interact with
207   worker-pool from starting execution.  This is useful for bound
209   execution is regulated by the system scheduler.
214   non-CPU-intensive work items can delay execution of CPU
220 workqueues are now non-reentrant - any work item is guaranteed to be
221 executed by at most one worker system-wide at any given time.
225 --------------
248 unbound worker-pools and only one work item could be active at any given
253 be used to achieve system-wide ST behavior.
346   special attribute, can use one of the system wq.  There is no
348   and a system wq.
398 .. kernel-doc:: include/linux/workqueue.h
400 .. kernel-doc:: kernel/workqueue.c