From: David Miller <davem@davemloft.net>
To: lipeng321@huawei.com
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxarm@huawei.com, yisen.zhuang@huawei.com,
salil.mehta@huawei.com
Subject: Re: [PATCH net-next 05/10] net: hns3: using modulo for cyclic counters in hclge_cmd_send
Date: Sat, 30 Jun 2018 21:03:42 +0900 (KST) [thread overview]
Message-ID: <20180630.210342.804224843120744818.davem@davemloft.net> (raw)
In-Reply-To: <1530271385-49668-6-git-send-email-lipeng321@huawei.com>
From: Peng Li <lipeng321@huawei.com>
Date: Fri, 29 Jun 2018 19:23:00 +0800
> @@ -228,8 +228,7 @@ int hclge_cmd_send(struct hclge_hw *hw, struct hclge_desc *desc, int num)
> desc_to_use = &hw->cmq.csq.desc[hw->cmq.csq.next_to_use];
> *desc_to_use = desc[handle];
> (hw->cmq.csq.next_to_use)++;
> - if (hw->cmq.csq.next_to_use == hw->cmq.csq.desc_num)
> - hw->cmq.csq.next_to_use = 0;
> + hw->cmq.csq.next_to_use %= hw->cmq.csq.desc_num;
> handle++;
I would advise against this.
The "%" modulus operation takes many cpu cycles, and the current code
is thus much faster.
next prev parent reply other threads:[~2018-06-30 12:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-29 11:22 [PATCH net-next 00/10] net: hns3: a few code improvements Peng Li
2018-06-29 11:22 ` [PATCH net-next 01/10] net: hns3: remove unused hclge_ring_to_dma_dir Peng Li
2018-06-29 11:22 ` [PATCH net-next 02/10] net: hns3: remove useless code in hclge_cmd_send Peng Li
2018-06-29 11:22 ` [PATCH net-next 03/10] net: hns3: remove some redundant assignments Peng Li
2018-06-29 11:22 ` [PATCH net-next 04/10] net: hns3: simplify hclge_cmd_csq_clean Peng Li
2018-06-29 11:23 ` [PATCH net-next 05/10] net: hns3: using modulo for cyclic counters in hclge_cmd_send Peng Li
2018-06-30 12:03 ` David Miller [this message]
2018-07-02 7:06 ` lipeng (Y)
2018-06-29 11:23 ` [PATCH net-next 06/10] net: hns3: remove a redundant hclge_cmd_csq_done Peng Li
2018-06-29 11:23 ` [PATCH net-next 07/10] net: hns3: remove some unused members of some structures Peng Li
2018-06-29 11:23 ` [PATCH net-next 08/10] net: hns3: give default option while dependency HNS3 set Peng Li
2018-06-29 11:23 ` [PATCH net-next 09/10] net: hns3: use dma_zalloc_coherent instead of kzalloc/dma_map_single Peng Li
2018-06-29 11:23 ` [PATCH net-next 10/10] net: hns3: modify hnae_ to hnae3_ Peng Li
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