From a7f99d0f2bbfe3b42ce398cdd37a97762e72cb56 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Fri, 1 Dec 2017 11:01:47 -0800 Subject: hv_netvsc: use reciprocal divide to speed up percent calculation Every packet sent checks the available ring space. The calculation can be sped up by using reciprocal divide which is multiplication. Since ring_size can only be configured by module parameter, so it doesn't have to be passed around everywhere. Also it should be unsigned since it is number of pages. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc_drv.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'drivers/net/hyperv/netvsc_drv.c') diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 5129647d420c..ba690e1737ab 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -54,9 +55,11 @@ #define LINKCHANGE_INT (2 * HZ) #define VF_TAKEOVER_INT (HZ / 10) -static int ring_size = 128; -module_param(ring_size, int, S_IRUGO); +static unsigned int ring_size __ro_after_init = 128; +module_param(ring_size, uint, S_IRUGO); MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)"); +unsigned int netvsc_ring_bytes __ro_after_init; +struct reciprocal_value netvsc_ring_reciprocal __ro_after_init; static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | NETIF_MSG_IFUP | @@ -860,7 +863,6 @@ static int netvsc_set_channels(struct net_device *net, memset(&device_info, 0, sizeof(device_info)); device_info.num_chn = count; - device_info.ring_size = ring_size; device_info.send_sections = nvdev->send_section_cnt; device_info.send_section_size = nvdev->send_section_size; device_info.recv_sections = nvdev->recv_section_cnt; @@ -975,7 +977,6 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) rndis_filter_close(nvdev); memset(&device_info, 0, sizeof(device_info)); - device_info.ring_size = ring_size; device_info.num_chn = nvdev->num_chn; device_info.send_sections = nvdev->send_section_cnt; device_info.send_section_size = nvdev->send_section_size; @@ -1539,7 +1540,6 @@ static int netvsc_set_ringparam(struct net_device *ndev, memset(&device_info, 0, sizeof(device_info)); device_info.num_chn = nvdev->num_chn; - device_info.ring_size = ring_size; device_info.send_sections = new_tx; device_info.send_section_size = nvdev->send_section_size; device_info.recv_sections = new_rx; @@ -1995,7 +1995,6 @@ static int netvsc_probe(struct hv_device *dev, /* Notify the netvsc driver of the new device */ memset(&device_info, 0, sizeof(device_info)); - device_info.ring_size = ring_size; device_info.num_chn = VRSS_CHANNEL_DEFAULT; device_info.send_sections = NETVSC_DEFAULT_TX; device_info.send_section_size = NETVSC_SEND_SECTION_SIZE; @@ -2158,11 +2157,13 @@ static int __init netvsc_drv_init(void) if (ring_size < RING_SIZE_MIN) { ring_size = RING_SIZE_MIN; - pr_info("Increased ring_size to %d (min allowed)\n", + pr_info("Increased ring_size to %u (min allowed)\n", ring_size); } - ret = vmbus_driver_register(&netvsc_drv); + netvsc_ring_bytes = ring_size * PAGE_SIZE; + netvsc_ring_reciprocal = reciprocal_value(netvsc_ring_bytes); + ret = vmbus_driver_register(&netvsc_drv); if (ret) return ret; -- cgit v1.2.1