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From: Jijie Shao <shaojijie@huawei.com>
To: <yisen.zhuang@huawei.com>, <salil.mehta@huawei.com>,
	<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
	<pabeni@redhat.com>, <horms@kernel.org>
CC: <shenjian15@huawei.com>, <wangjie125@huawei.com>,
	<liuyonglong@huawei.com>, <shaojijie@huawei.com>, <chenhao418@huawei.com>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH net 2/2] net: hns3: add cond_resched() to hns3 ring buffer init process
Date: Wed, 5 Jun 2024 15:20:58 +0800
Message-ID: <20240605072058.2027992-3-shaojijie@huawei.com>
In-Reply-To: <20240605072058.2027992-1-shaojijie@huawei.com>
References: <20240605072058.2027992-1-shaojijie@huawei.com>
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From: Jie Wang <wangjie125@huawei.com>

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 <wangjie125@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
---
 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