[PATCH 1/3] workqueue: remove the first check and the return value of maybe_create_worker()

From: Lai Jiangshan
Date: Thu Jul 10 2014 - 12:00:58 EST


The pool->lock is kept locked during the time the worker_thread() checks the
condition and maybe_create_worker() is called, therefore, the condition
is unchanged and the first condition check is unneeded.

After this unneeded check is removed, maybe_create_worker() only returns
true, so we remove the return value of it and adjust the call-site.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
kernel/workqueue.c | 18 +++++-------------
1 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f344334..92f7ea0c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1887,17 +1887,11 @@ static void pool_mayday_timeout(unsigned long __pool)
* spin_lock_irq(pool->lock) which may be released and regrabbed
* multiple times. Does GFP_KERNEL allocations. Called only from
* manager.
- *
- * Return:
- * %false if no action was taken and pool->lock stayed locked, %true
- * otherwise.
*/
-static bool maybe_create_worker(struct worker_pool *pool)
+static void maybe_create_worker(struct worker_pool *pool)
__releases(&pool->lock)
__acquires(&pool->lock)
{
- if (!need_to_create_worker(pool))
- return false;
restart:
spin_unlock_irq(&pool->lock);

@@ -1914,7 +1908,7 @@ restart:
start_worker(worker);
if (WARN_ON_ONCE(need_to_create_worker(pool)))
goto restart;
- return true;
+ return;
}

if (!need_to_create_worker(pool))
@@ -1930,7 +1924,6 @@ restart:
spin_lock_irq(&pool->lock);
if (need_to_create_worker(pool))
goto restart;
- return true;
}

/**
@@ -1959,7 +1952,6 @@ restart:
static bool manage_workers(struct worker *worker)
{
struct worker_pool *pool = worker->pool;
- bool ret = false;

/*
* Anyone who successfully grabs manager_arb wins the arbitration
@@ -1972,12 +1964,12 @@ static bool manage_workers(struct worker *worker)
* actual management, the pool may stall indefinitely.
*/
if (!mutex_trylock(&pool->manager_arb))
- return ret;
+ return false;

- ret |= maybe_create_worker(pool);
+ maybe_create_worker(pool);

mutex_unlock(&pool->manager_arb);
- return ret;
+ return true;
}

/**
--
1.7.4.4

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