src/sys/kern/subr_taskqueue.c, branch releng/10.2

MFC r258713,262062: add taskqueue_drain_all

2014-02-17T15:32:08Z

MFC r258354: taskqueue_cancel: garbage collect a write-only variable

2014-01-16T14:11:45Z

MFprojects/camlock r254460:

2013-08-24T14:41:49Z

Remove locking from taskqueue_member(). The list of threads is static during the taskqueue life cycle, so there is no need to protect it, taking quite congested lock several more times for each ZFS I/O.

Extend taskqueue(9) to enable per-taskqueue callbacks.

2013-03-23T15:11:53Z

The scope of these callbacks is primarily to support actions that affect the taskqueue's thread environments. They are entirely optional, and consequently are introduced as a new API: taskqueue_set_callback(). This interface allows the caller to specify that a taskqueue requires a callback and optional context pointer for a given callback type. The callback types included in this commit can be used to register a constructor and destructor for thread-local storage using osd(9). This allows a particular taskqueue to define that its threads require a specific type of TLS, without the need for a specially-orchestrated task-based mechanism for startup and shutdown in order to accomplish it. Two callback types are supported at this point: - TASKQUEUE_CALLBACK_TYPE_INIT, called by every thread when it starts, prior to processing any tasks. - TASKQUEUE_CALLBACK_TYPE_SHUTDOWN, called by every thread when it exits, after it has processed its last task but before the taskqueue is reclaimed. While I'm here: - Add two new macros, TQ_ASSERT_LOCKED and TQ_ASSERT_UNLOCKED, and use them in appropriate locations. - Fix taskqueue.9 to mention taskqueue_start_threads(), which is a required interface for all consumers of taskqueue(9). Reviewed by: kib (all), eadler (taskqueue.9), brd (taskqueue.9) Approved by: ken (mentor) Sponsored by: Spectra Logic MFC after: 1 month

Add a special meaning to the negative ticks argument for

2012-11-20T15:33:48Z

taskqueue_enqueue_timeout(). Do not rearm the callout if it is already armed and the ticks is negative. Otherwise rearm it to fire in abs(ticks) ticks in the future. The intended use is to call taskqueue_enqueue_timeout() for the given timeout_task with the same negative ticks argument. As result, the task is scheduled to execute not further than abs(ticks) ticks in future, and the consequent enqueues are coalesced until the already scheduled task is finished. Reviewed by: rwatson Tested by: Markus Gebert MFC after: 2 weeks

Shorten the name of the fast SWI taskqueue to "fast taskq" so that

2012-08-28T13:35:37Z

it fits. Reported by: lev MFC after: 1 week

Ensure that ta_pending doesn't overflow u_short by capping its value at USHRT_MAX.

2011-09-15T08:42:06Z

If it overflows before the taskqueue can run, the task will be re-added to the taskqueue and cause a loop in the task list. Reported by: Arnaud Lacombe Submitted by: Ryan Stone Reviewed by: jhb Approved by: re (kib) MFC after: 1 day

Implement the delayed task execution extension to the taskqueue

2011-04-26T11:39:56Z

mechanism. The caller may specify a timeout in ticks after which the task will be scheduled. Sponsored by: The FreeBSD Foundation Reviewed by: jeff, jhb MFC after: 1 month

taskqueue: drop unused tq_name field

2010-11-23T14:30:22Z

tq_name was used write-only and besides it was just a pointer, so it could point to some garbage in a temporary buffer that's gone. This change shouldn't change KPI/KBI as struct taskqueue is private to subr_taskqueue.c. If we find a need for tq_name it can be resurrected at any moment. taskqueue_create() interface is preserved for this purpose. Suggested by: jhb MFC after: 10 days

Use macros rather than inline functions to lock and unlock mutexes, so that

2010-11-08T22:12:25Z

line number information is preserved in witness. Reviewed by: jhb