2024-06-05 07:27:20

by Jijie Shao

Subject: [PATCH net 2/2] net: hns3: add cond_resched() to hns3 ring buffer init process

From: Jie Wang <[email protected]>

Currently hns3 ring buffer init process would hold cpu too long with big
Tx/Rx ring depth. This could cause soft lockup.

So this patch adds cond_resched() to the process. Then cpu can break to
run other tasks instead of busy looping.

Fixes: a723fb8efe29 ("net: hns3: refine for set ring parameters")
Signed-off-by: Jie Wang <[email protected]>
Signed-off-by: Jijie Shao <[email protected]>
---
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++++
drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 ++
2 files changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index ff71fb1eced9..a5fc0209d628 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -3535,6 +3535,9 @@ static int hns3_alloc_ring_buffers(struct hns3_enet_ring *ring)
ret = hns3_alloc_and_attach_buffer(ring, i);
if (ret)
goto out_buffer_fail;
+
+ if (!(i % HNS3_RESCHED_BD_NUM))
+ cond_resched();
}

return 0;
@@ -5107,6 +5110,7 @@ int hns3_init_all_ring(struct hns3_nic_priv *priv)
}

u64_stats_init(&priv->ring[i].syncp);
+ cond_resched();
}

return 0;
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
index acd756b0c7c9..d36c4ed16d8d 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -214,6 +214,8 @@ enum hns3_nic_state {
#define HNS3_CQ_MODE_EQE 1U
#define HNS3_CQ_MODE_CQE 0U

+#define HNS3_RESCHED_BD_NUM 1024
+
enum hns3_pkt_l2t_type {
HNS3_L2_TYPE_UNICAST,
HNS3_L2_TYPE_MULTICAST,
--
2.30.0

2024-06-06 16:27:26

by Simon Horman

Subject: Re: [PATCH net 2/2] net: hns3: add cond_resched() to hns3 ring buffer init process

On Wed, Jun 05, 2024 at 03:20:58PM +0800, Jijie Shao wrote:
> From: Jie Wang <[email protected]>
>
> Currently hns3 ring buffer init process would hold cpu too long with big
> Tx/Rx ring depth. This could cause soft lockup.
>
> So this patch adds cond_resched() to the process. Then cpu can break to
> run other tasks instead of busy looping.
>
> Fixes: a723fb8efe29 ("net: hns3: refine for set ring parameters")
> Signed-off-by: Jie Wang <[email protected]>
> Signed-off-by: Jijie Shao <[email protected]>

Reviewed-by: Simon Horman <[email protected]>