On 12/7/20 4:02 AM, Peter Zijlstra wrote:
On Thu, Dec 03, 2020 at 08:59:13PM -0500, Waiman Long wrote:
On 12/3/20 3:11 PM, Eric W. Biederman wrote:
+static inline int __down_read_interruptible(struct rw_semaphore *sem)
+{
+ if (!rwsem_read_trylock(sem)) {
+ if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))
+ return -EINTR;
+ DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
+ } else {
+ rwsem_set_reader_owned(sem);
+ }
+ return 0;
+}
+
static inline int __down_read_killable(struct rw_semaphore *sem)
{
if (!rwsem_read_trylock(sem)) {
@@ -1495,6 +1507,20 @@ void __sched down_read(struct rw_semaphore *sem)
}
EXPORT_SYMBOL(down_read);
+int __sched down_read_interruptible(struct rw_semaphore *sem)
+{
+ might_sleep();
+ rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
+
+ if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock,
__down_read_interruptible)) {
+ rwsem_release(&sem->dep_map, _RET_IP_);
+ return -EINTR;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(down_read_interruptible);
+
int __sched down_read_killable(struct rw_semaphore *sem)
{
might_sleep();
Acked-by: Waiman Long <long...@redhat.com>
Yeah, that seems correct.. There's an unfortunate amount of copy-paste
there though.
Do we want to follow that up with something like this?
I am actually thinking about similar streamlining once the patch lands.
Your suggested changes look fine to me.
Cheers,
Longman
