Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [PATCH 17/21] workqueue: simplify workqueue_cpu_up_callback(CPU_ONLINE) | Date | Wed, 20 Mar 2013 03:28:17 +0800 |
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If we have 4096 CPUs, workqueue_cpu_up_callback() will travel too much CPUs, to avoid it, we use for_each_cpu_worker_pool for the cpu pools and use unbound_pool_hash for unbound pools.
After it, for_each_pool() becomes unused, so we remove it.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- kernel/workqueue.c | 55 +++++++++++++++++----------------------------------- 1 files changed, 18 insertions(+), 37 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 29c5baa..21ef721 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -317,23 +317,6 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to, (pool)++) /** - * for_each_pool - iterate through all worker_pools in the system - * @pool: iteration cursor - * @pi: integer used for iteration - * - * This must be called either with pools_mutex held or sched RCU read locked. - * If the pool needs to be used beyond the locking in effect, the caller is - * responsible for guaranteeing that the pool stays online. - * - * The if/else clause exists only for the lockdep assertion and can be - * ignored. - */ -#define for_each_pool(pool, pi) \ - idr_for_each_entry(&worker_pool_idr, pool, pi) \ - if (({ assert_rcu_or_pools_mutex(); false; })) { } \ - else - -/** * for_each_pool_worker - iterate through all workers of a worker_pool * @worker: iteration cursor * @wi: integer used for iteration @@ -4011,7 +3994,7 @@ static void associate_cpu_pool(struct worker_pool *pool) struct worker *worker; int wi; - lockdep_assert_held(&pool->manager_mutex); + mutex_lock(&pool->manager_mutex); /* * Restore CPU affinity of all workers. As all idle workers should @@ -4023,7 +4006,7 @@ static void associate_cpu_pool(struct worker_pool *pool) for_each_pool_worker(worker, wi, pool) if (WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0)) - return; + goto out_unlock; spin_lock_irq(&pool->lock); @@ -4064,6 +4047,9 @@ static void associate_cpu_pool(struct worker_pool *pool) pool->flags &= ~POOL_DISASSOCIATED; spin_unlock_irq(&pool->lock); + +out_unlock: + mutex_unlock(&pool->manager_mutex); } /** @@ -4078,25 +4064,28 @@ static void associate_cpu_pool(struct worker_pool *pool) */ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) { - static cpumask_t cpumask; + static cpumask_t cpumask; /* protected by pools_mutex */ struct worker *worker; int wi; - lockdep_assert_held(&pool->manager_mutex); + mutex_lock(&pool->manager_mutex); /* is @cpu allowed for @pool? */ if (!cpumask_test_cpu(cpu, pool->attrs->cpumask)) - return; + goto out_unlock; /* is @cpu the only online CPU? */ cpumask_and(&cpumask, pool->attrs->cpumask, cpu_online_mask); if (cpumask_weight(&cpumask) != 1) - return; + goto out_unlock; /* as we're called from CPU_ONLINE, the following shouldn't fail */ for_each_pool_worker(worker, wi, pool) WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0); + +out_unlock: + mutex_unlock(&pool->manager_mutex); } /* @@ -4109,7 +4098,7 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb, { int cpu = (unsigned long)hcpu; struct worker_pool *pool; - int pi; + int bkt; switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: @@ -4123,20 +4112,12 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb, case CPU_DOWN_FAILED: case CPU_ONLINE: - mutex_lock(&pools_mutex); - - for_each_pool(pool, pi) { - mutex_lock(&pool->manager_mutex); - - if (pool->cpu == cpu) { - associate_cpu_pool(pool); - } else if (pool->cpu < 0) { - restore_unbound_workers_cpumask(pool, cpu); - } - - mutex_unlock(&pool->manager_mutex); - } + for_each_cpu_worker_pool(pool, cpu) + associate_cpu_pool(pool); + mutex_lock(&pools_mutex); + hash_for_each(unbound_pool_hash, bkt, pool, hash_node) + restore_unbound_workers_cpumask(pool, cpu); mutex_unlock(&pools_mutex); break; } -- 1.7.7.6
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