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authorTejun Heo <tj@kernel.org>2013-04-01 17:08:13 -0700
committerTejun Heo <tj@kernel.org>2013-04-01 18:45:36 -0700
commit229641a6f1f09e27a1f12fba38980f33f4c92975 (patch)
tree234a6f8aea0910de3242af0bbe6d7494fcf81847 /kernel/rcutree.c
parentd55262c4d164759a8debe772da6c9b16059dec47 (diff)
parent07961ac7c0ee8b546658717034fe692fd12eefa9 (diff)
Merge tag 'v3.9-rc5' into wq/for-3.10
Writeback conversion to workqueue will be based on top of wq/for-3.10 branch to take advantage of custom attrs and NUMA support for unbound workqueues. Mainline currently contains two commits which result in non-trivial merge conflicts with wq/for-3.10 and because block/for-3.10/core is based on v3.9-rc3 which contains one of the conflicting commits, we need a pre-merge-window merge anyway. Let's pull v3.9-rc5 into wq/for-3.10 so that the block tree doesn't suffer from workqueue merge conflicts. The two conflicts and their resolutions: * e68035fb65 ("workqueue: convert to idr_alloc()") in mainline changes worker_pool_assign_id() to use idr_alloc() instead of the old idr interface. worker_pool_assign_id() goes through multiple locking changes in wq/for-3.10 causing the following conflict. static int worker_pool_assign_id(struct worker_pool *pool) { int ret; <<<<<<< HEAD lockdep_assert_held(&wq_pool_mutex); do { if (!idr_pre_get(&worker_pool_idr, GFP_KERNEL)) return -ENOMEM; ret = idr_get_new(&worker_pool_idr, pool, &pool->id); } while (ret == -EAGAIN); ======= mutex_lock(&worker_pool_idr_mutex); ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL); if (ret >= 0) pool->id = ret; mutex_unlock(&worker_pool_idr_mutex); >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89 return ret < 0 ? ret : 0; } We want locking from the former and idr_alloc() usage from the latter, which can be combined to the following. static int worker_pool_assign_id(struct worker_pool *pool) { int ret; lockdep_assert_held(&wq_pool_mutex); ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL); if (ret >= 0) { pool->id = ret; return 0; } return ret; } * eb2834285c ("workqueue: fix possible pool stall bug in wq_unbind_fn()") updated wq_unbind_fn() such that it has single larger for_each_std_worker_pool() loop instead of two separate loops with a schedule() call inbetween. wq/for-3.10 renamed pool->assoc_mutex to pool->manager_mutex causing the following conflict (earlier function body and comments omitted for brevity). static void wq_unbind_fn(struct work_struct *work) { ... spin_unlock_irq(&pool->lock); <<<<<<< HEAD mutex_unlock(&pool->manager_mutex); } ======= mutex_unlock(&pool->assoc_mutex); >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89 schedule(); <<<<<<< HEAD for_each_cpu_worker_pool(pool, cpu) ======= >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89 atomic_set(&pool->nr_running, 0); spin_lock_irq(&pool->lock); wake_up_worker(pool); spin_unlock_irq(&pool->lock); } } The resolution is mostly trivial. We want the control flow of the latter with the rename of the former. static void wq_unbind_fn(struct work_struct *work) { ... spin_unlock_irq(&pool->lock); mutex_unlock(&pool->manager_mutex); schedule(); atomic_set(&pool->nr_running, 0); spin_lock_irq(&pool->lock); wake_up_worker(pool); spin_unlock_irq(&pool->lock); } } Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/rcutree.c')
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