Based on its name you would think that rqst_should_sleep() would be
read-only, not changing anything. But it fact it will clear
SP_TASK_PENDING if that was set. This is surprising, and it blurs the
line between "check for work to do" and "dequeue work to do".
So change the "test_and_clear" to simple "test" and clear the bit once
the thread has decided to wake up and return to the caller.
With this, it makes sense to *always* set SP_TASK_PENDING when asked,
rather than only to set it if no thread could be woken up.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
net/sunrpc/svc_xprt.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index cd92cb54132d..380fb3caea4c 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -581,8 +581,8 @@ void svc_wake_up(struct svc_serv *serv)
{
struct svc_pool *pool = &serv->sv_pools[0];
- if (!svc_pool_wake_idle_thread(serv, pool))
- set_bit(SP_TASK_PENDING, &pool->sp_flags);
+ set_bit(SP_TASK_PENDING, &pool->sp_flags);
+ svc_pool_wake_idle_thread(serv, pool);
}
EXPORT_SYMBOL_GPL(svc_wake_up);
@@ -704,7 +704,7 @@ rqst_should_sleep(struct svc_rqst *rqstp)
struct svc_pool *pool = rqstp->rq_pool;
/* did someone call svc_wake_up? */
- if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags))
+ if (test_bit(SP_TASK_PENDING, &pool->sp_flags))
return false;
/* was a socket queued? */
@@ -750,6 +750,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp)
set_bit(RQ_BUSY, &rqstp->rq_flags);
smp_mb__after_atomic();
+ clear_bit(SP_TASK_PENDING, &pool->sp_flags);
rqstp->rq_xprt = svc_xprt_dequeue(pool);
if (rqstp->rq_xprt) {
trace_svc_pool_awoken(rqstp);
@@ -761,6 +762,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp)
percpu_counter_inc(&pool->sp_threads_no_work);
return NULL;
out_found:
+ clear_bit(SP_TASK_PENDING, &pool->sp_flags);
/* Normally we will wait up to 5 seconds for any required
* cache information to be provided.
*/
--
2.40.1
