diff options
| author | NeilBrown <neilb@suse.de> | 2022-03-07 00:41:44 +0100 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2022-03-13 17:59:35 +0100 |
| commit | a80a8461868905823609be97f91776a26befe839 (patch) | |
| tree | a13a68e25b6b7fb3b8e505ab330539691a84a473 | |
| parent | SUNRPC/xprt: async tasks mustn't block waiting for memory (diff) | |
| download | linux-a80a8461868905823609be97f91776a26befe839.tar.xz linux-a80a8461868905823609be97f91776a26befe839.zip | |
SUNRPC: remove scheduling boost for "SWAPPER" tasks.
Currently, tasks marked as "swapper" tasks get put to the front of
non-priority rpc_queues, and are sorted earlier than non-swapper tasks on
the transport's ->xmit_queue.
This is pointless as currently *all* tasks for a mount that has swap
enabled on *any* file are marked as "swapper" tasks. So the net result
is that the non-priority rpc_queues are reverse-ordered (LIFO).
This scheduling boost is not necessary to avoid deadlocks, and hurts
fairness, so remove it. If there were a need to expedite some requests,
the tk_priority mechanism is a more appropriate tool.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
| -rw-r--r-- | net/sunrpc/sched.c | 7 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 11 |
2 files changed, 0 insertions, 18 deletions
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index e5b07562ba45..690bd3401820 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -186,11 +186,6 @@ static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, /* * Add new request to wait queue. - * - * Swapper tasks always get inserted at the head of the queue. - * This should avoid many nasty memory deadlocks and hopefully - * improve overall performance. - * Everyone else gets appended to the queue to ensure proper FIFO behavior. */ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task, @@ -199,8 +194,6 @@ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, INIT_LIST_HEAD(&task->u.tk_wait.timer_list); if (RPC_IS_PRIORITY(queue)) __rpc_add_wait_queue_priority(queue, task, queue_priority); - else if (RPC_IS_SWAPPER(task)) - list_add(&task->u.tk_wait.list, &queue->tasks[0]); else list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); task->tk_waitqueue = queue; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 2d1f84aea516..2f165634df54 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1354,17 +1354,6 @@ xprt_request_enqueue_transmit(struct rpc_task *task) INIT_LIST_HEAD(&req->rq_xmit2); goto out; } - } else if (RPC_IS_SWAPPER(task)) { - list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { - if (pos->rq_cong || pos->rq_bytes_sent) - continue; - if (RPC_IS_SWAPPER(pos->rq_task)) - continue; - /* Note: req is added _before_ pos */ - list_add_tail(&req->rq_xmit, &pos->rq_xmit); - INIT_LIST_HEAD(&req->rq_xmit2); - goto out; - } } else if (!req->rq_seqno) { list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { if (pos->rq_task->tk_owner != task->tk_owner) |