From 0e8633419641bfd6444ba31e87c8cd7f51620fc1 Mon Sep 17 00:00:00 2001 From: Sepherosa Ziehau Date: Mon, 11 Apr 2016 06:31:52 +0000 Subject: [PATCH] hyperv/hn: Cap default # of rings to 8. 8 gives the best performance in both Azure and local Hyper-V on both 10Ge and 40Ge. More rings are still allowed by manual configuration. Reviewed by: Dexuan Cui MFC after: 1 week Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D5879 --- sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c index acc49b4540c..fb0e8e52a6c 100644 --- a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c +++ b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c @@ -136,6 +136,8 @@ __FBSDID("$FreeBSD$"); #define HN_LROENT_CNT_DEF 128 +#define HN_RING_CNT_DEF_MAX 8 + #define HN_RNDIS_MSG_LEN \ (sizeof(rndis_msg) + \ RNDIS_HASH_PPI_SIZE + \ @@ -460,8 +462,14 @@ netvsc_attach(device_t dev) * The # of RX rings to use is same as the # of channels to use. */ ring_cnt = hn_chan_cnt; - if (ring_cnt <= 0 || ring_cnt > mp_ncpus) + if (ring_cnt <= 0) { + /* Default */ ring_cnt = mp_ncpus; + if (ring_cnt > HN_RING_CNT_DEF_MAX) + ring_cnt = HN_RING_CNT_DEF_MAX; + } else if (ring_cnt > mp_ncpus) { + ring_cnt = mp_ncpus; + } tx_ring_cnt = hn_tx_ring_cnt; if (tx_ring_cnt <= 0 || tx_ring_cnt > ring_cnt)