diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2019-06-23 12:56:11 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2019-06-23 12:56:11 +0000 |
| commit | ae7cad33495c99a6d11a82c999947dc9e3df78f7 (patch) | |
| tree | f89c810fbe80b96621e01c05a2ad0d90cf713850 /sys/kern | |
| parent | 5a7996f8224a39f7cbcce2755f46572678dea144 (diff) | |
Make taskq_barrier(9) work for multi-threaded task queues.
ok visa@
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_task.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/sys/kern/kern_task.c b/sys/kern/kern_task.c index 74f3ea4ab18..c553caca8ec 100644 --- a/sys/kern/kern_task.c +++ b/sys/kern/kern_task.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_task.c,v 1.25 2019/04/28 04:20:40 dlg Exp $ */ +/* $OpenBSD: kern_task.c,v 1.26 2019/06/23 12:56:10 kettenis Exp $ */ /* * Copyright (c) 2013 David Gwynne <dlg@openbsd.org> @@ -43,6 +43,7 @@ struct taskq { TQ_S_DESTROYED } tq_state; unsigned int tq_running; + unsigned int tq_waiting; unsigned int tq_nthreads; unsigned int tq_flags; const char *tq_name; @@ -59,6 +60,7 @@ static const char taskq_sys_name[] = "systq"; struct taskq taskq_sys = { TQ_S_CREATED, 0, + 0, 1, 0, taskq_sys_name, @@ -77,6 +79,7 @@ static const char taskq_sys_mp_name[] = "systqmp"; struct taskq taskq_sys_mp = { TQ_S_CREATED, 0, + 0, 1, TASKQ_MPSAFE, taskq_sys_mp_name, @@ -122,6 +125,7 @@ taskq_create(const char *name, unsigned int nthreads, int ipl, tq->tq_state = TQ_S_CREATED; tq->tq_running = 0; + tq->tq_waiting = 0; tq->tq_nthreads = nthreads; tq->tq_name = name; tq->tq_flags = flags; @@ -223,6 +227,7 @@ taskq_barrier(struct taskq *tq) WITNESS_CHECKORDER(&tq->tq_lock_object, LOP_NEWORDER, NULL); + SET(t.t_flags, TASK_BARRIER); task_add(tq, &t); cond_wait(&c, "tqbar"); } @@ -238,6 +243,7 @@ taskq_del_barrier(struct taskq *tq, struct task *del) if (task_del(tq, del)) return; + SET(t.t_flags, TASK_BARRIER); task_add(tq, &t); cond_wait(&c, "tqbar"); } @@ -304,13 +310,30 @@ taskq_next_work(struct taskq *tq, struct task *work) struct task *next; mtx_enter(&tq->tq_mtx); +retry: while ((next = TAILQ_FIRST(&tq->tq_worklist)) == NULL) { if (tq->tq_state != TQ_S_RUNNING) { mtx_leave(&tq->tq_mtx); return (0); } + tq->tq_waiting++; msleep(tq, &tq->tq_mtx, PWAIT, "bored", 0); + tq->tq_waiting--; + } + + if (ISSET(next->t_flags, TASK_BARRIER)) { + /* + * Make sure all other threads are sleeping before we + * proceed and run the barrier task. + */ + if (++tq->tq_waiting == tq->tq_nthreads) { + tq->tq_waiting--; + } else { + msleep(tq, &tq->tq_mtx, PWAIT, "tqblk", 0); + tq->tq_waiting--; + goto retry; + } } TAILQ_REMOVE(&tq->tq_worklist, next, t_entry); |