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From:   NeilBrown <neilb@suse.de>
To:     Chuck Lever <chuck.lever@oracle.com>,
        Jeff Layton <jlayton@kernel.org>
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 6/6] SUNRPC: discard SP_CONGESTED
Date:   Wed,  2 Aug 2023 17:34:43 +1000
Message-Id: <20230802073443.17965-7-neilb@suse.de>
In-Reply-To: <20230802073443.17965-1-neilb@suse.de>
References: <20230802073443.17965-1-neilb@suse.de>
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We can tell if a pool is congested by checking if the idle list is
empty.  We don't need a separate flag.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 include/linux/sunrpc/svc.h | 1 -
 net/sunrpc/svc.c           | 1 -
 net/sunrpc/svc_xprt.c      | 4 +---
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 8b93af92dd53..5ea76d432015 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -50,7 +50,6 @@ struct svc_pool {
 /* bits for sp_flags */
 enum {
 	SP_TASK_PENDING,	/* still work to do even if no xprt is queued */
-	SP_CONGESTED,		/* all threads are busy, none idle */
 	SP_NEED_VICTIM,		/* One thread needs to agree to exit */
 	SP_VICTIM_REMAINS,	/* One thread needs to actually exit */
 };
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index dce433dea1bd..5df7b4353320 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -718,7 +718,6 @@ void svc_pool_wake_idle_thread(struct svc_pool *pool)
 	}
 	rcu_read_unlock();
 
-	set_bit(SP_CONGESTED, &pool->sp_flags);
 }
 EXPORT_SYMBOL_GPL(svc_pool_wake_idle_thread);
 
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index e44efcc21b63..dd60e5810cdb 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -735,8 +735,6 @@ static void svc_rqst_wait_for_work(struct svc_rqst *rqstp)
 
 	if (rqst_should_sleep(rqstp)) {
 		set_current_state(TASK_IDLE);
-		smp_mb__before_atomic();
-		clear_bit(SP_CONGESTED, &pool->sp_flags);
 		spin_lock_bh(&pool->sp_lock);
 		list_add(&rqstp->rq_idle, &pool->sp_idle_threads);
 		spin_unlock_bh(&pool->sp_lock);
@@ -873,7 +871,7 @@ void svc_recv(struct svc_rqst *rqstp)
 		/* Normally we will wait up to 5 seconds for any required
 		 * cache information to be provided.
 		 */
-		if (test_bit(SP_CONGESTED, &pool->sp_flags))
+		if (list_empty(&pool->sp_idle_threads))
 			rqstp->rq_chandle.thread_wait = 5 * HZ;
 		else
 			rqstp->rq_chandle.thread_wait = 1 * HZ;
-- 
2.40.1