[PATCH 5/9 V3] workqueue: move rebind_hold to idle_rebind

From: Lai Jiangshan
Date: Wed Aug 29 2012 - 12:52:53 EST


By the help of @idle_rebind.ref_done, the life time of idle_rebind
is expanded enough and it can include the whole reference-time
of @rebind_hold, so we can move @rebind_hold from gcwq to idle_rebind.

Also we change it to completion instead. we need to ease the pain of WORKER_REBIND.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
kernel/workqueue.c | 20 ++++++++------------
1 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e40898a..eeb5752 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -185,8 +185,6 @@ struct global_cwq {
/* L: hash of busy workers */

struct worker_pool pools[2]; /* normal and highpri pools */
-
- wait_queue_head_t rebind_hold; /* rebind hold wait */
} ____cacheline_aligned_in_smp;

/*
@@ -1327,15 +1325,16 @@ struct idle_rebind {
int idle_cnt; /* # idle workers to be rebound */
struct completion idle_done; /* all idle workers rebound */

+ /* idle workers wait all idles to be rebound */
+ struct completion rebind_hold;
+
/*
* notify the rebind_workers() that:
- * 0. All worker leave rebind_hold:
* 1. All idle workers are rebound.
* 2. No idle worker has ref to this struct
*
* @ref_cnt: # idle workers has ref to this struct
* @ref_done: any idle workers has no ref to this struct,
- * nor rebind_hold.
* it also implies that all idle workers are rebound.
*/
int ref_cnt;
@@ -1349,8 +1348,6 @@ struct idle_rebind {
*/
static void idle_worker_rebind(struct worker *worker)
{
- struct global_cwq *gcwq = worker->pool->gcwq;
-
/* CPU must be online at this point */
WARN_ON(!worker_maybe_bind_and_lock(worker));
if (!--worker->idle_rebind->idle_cnt)
@@ -1358,7 +1355,7 @@ static void idle_worker_rebind(struct worker *worker)
spin_unlock_irq(&worker->pool->gcwq->lock);

/* we did our part, wait for rebind_workers() to finish up */
- wait_event(gcwq->rebind_hold, !(worker->flags & WORKER_REBIND));
+ wait_for_completion(&worker->idle_rebind->rebind_hold);

/* noify if all idle worker are done(rebond & wait) */
spin_lock_irq(&worker->pool->gcwq->lock);
@@ -1425,11 +1422,12 @@ static void rebind_workers(struct global_cwq *gcwq)
/*
* Rebind idle workers. Interlocked both ways in triple waits.
* We wait for workers to rebind via @idle_rebind.idle_done.
- * Workers will wait for us to finish up by watching %WORKER_REBIND.
+ * Workers will wait for us via @idle_rebind.rebind_hold.
* And them we wait for workers to leave rebind_hold
* via @idle_rebind.ref_done.
*/
init_completion(&idle_rebind.idle_done);
+ init_completion(&idle_rebind.rebind_hold);
init_completion(&idle_rebind.ref_done);
idle_rebind.ref_cnt = 1;
retry:
@@ -1473,7 +1471,7 @@ retry:
list_for_each_entry(worker, &pool->idle_list, entry)
worker->flags &= ~WORKER_REBIND;

- wake_up_all(&gcwq->rebind_hold);
+ complete_all(&idle_rebind.rebind_hold);

/* rebind busy workers */
for_each_busy_worker(worker, i, pos, gcwq) {
@@ -1499,7 +1497,7 @@ retry:

/*
* we will leave rebind_workers(), have to wait until no worker
- * has ref to this idle_rebind nor rebind_hold.
+ * has ref to this idle_rebind.
*/
if (--idle_rebind.ref_cnt) {
spin_unlock_irq(&gcwq->lock);
@@ -3789,8 +3787,6 @@ static int __init init_workqueues(void)
mutex_init(&pool->manager_mutex);
ida_init(&pool->worker_ida);
}
-
- init_waitqueue_head(&gcwq->rebind_hold);
}

/* create the initial worker */
--
1.7.4.4

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