Messages in this thread Patch in this message | | | Date | Wed, 11 May 2016 10:44:01 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 03/11] locking, rwsem: introduce basis for down_write_killable |
| |
On Wed, May 11, 2016 at 10:28:53AM +0200, Michal Hocko wrote:
> Does the following look correct/reasonable? This is absolutely untested > and more for a discussion:
I would much rather see it in common; something like so perhaps.
--- kernel/locking/rwsem-xadd.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index df4dcb883b50..5d7f2831a475 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -487,11 +487,9 @@ __rwsem_down_write_failed_common(struct rw_semaphore *sem, int state) /* Block until there are no active lockers. */ do { - if (signal_pending_state(state, current)) { - raw_spin_lock_irq(&sem->wait_lock); - ret = ERR_PTR(-EINTR); - goto out; - } + if (signal_pending_state(state, current)) + goto out_nolock; + schedule(); set_current_state(state); } while ((count = sem->count) & RWSEM_ACTIVE_MASK); @@ -504,6 +502,18 @@ __rwsem_down_write_failed_common(struct rw_semaphore *sem, int state) raw_spin_unlock_irq(&sem->wait_lock); return ret; + +out_nolock: + __set_current_state(TASK_RUNNING); + raw_spin_lock_irq(&sem->wait_lock); + list_del(&waiter.list); + if (list_empty(&sem->wait_list)) + rwsem_atomic_update(-RWSEM_WAITING_BIAS, sem); + else + __rwsem_do_wake(sem, RWSEM_WAKE_READERS); + raw_spin_unlock_irq(&sem->wait_lock); + + return ERR_PTR(-EINTR); } __visible struct rw_semaphore * __sched
| |