From: Sagi Grimberg <sagi@grimberg.me>
To: linux-nvme@lists.infradead.org
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
Subject: [PATCH v2] nvmet-rdma: Avoid o(n^2) loop in delete_ctrl
Date: Tue, 7 May 2024 09:54:44 +0300 [thread overview]
Message-ID: <20240507065444.1109334-1-sagi@grimberg.me> (raw)
From: Sagi Grimberg <sagi.grimberg@vastdata.com>
When deleting a nvmet-rdma ctrl, we essentially loop over all
queues that belong to the controller and schedule a removal of
each. Instead of restarting the loop every time a queue is found,
do a simple safe list traversal.
This addresses an unneeded time spent scheduling queue removal in
cases there a lot of queues.
Signed-off-by: Sagi Grimberg <sagi.grimberg@vastdata.com>
---
Changes from v1:
- address exceed 80 characters
drivers/nvme/target/rdma.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 5b8c63e74639..955296ac377f 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1814,18 +1814,14 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
{
- struct nvmet_rdma_queue *queue;
+ struct nvmet_rdma_queue *queue, *n;
-restart:
mutex_lock(&nvmet_rdma_queue_mutex);
- list_for_each_entry(queue, &nvmet_rdma_queue_list, queue_list) {
- if (queue->nvme_sq.ctrl == ctrl) {
- list_del_init(&queue->queue_list);
- mutex_unlock(&nvmet_rdma_queue_mutex);
-
- __nvmet_rdma_queue_disconnect(queue);
- goto restart;
- }
+ list_for_each_entry_safe(queue, n, &nvmet_rdma_queue_list, queue_list) {
+ if (queue->nvme_sq.ctrl != ctrl)
+ continue;
+ list_del_init(&queue->queue_list);
+ __nvmet_rdma_queue_disconnect(queue);
}
mutex_unlock(&nvmet_rdma_queue_mutex);
}
--
2.40.1
next reply other threads:[~2024-05-07 6:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 6:54 Sagi Grimberg [this message]
2024-05-07 7:26 ` [PATCH v2] nvmet-rdma: Avoid o(n^2) loop in delete_ctrl Christoph Hellwig
2024-05-07 15:08 ` Keith Busch
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