From f4e403633bcd290a4db2568364657d07b42ff890 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Fri, 28 Jul 2017 08:59:47 -0700 Subject: [PATCH] netvsc: signal host if receive ring is emptied Latency improvement related to NAPI conversion. If all packets are processed from receive ring then need to signal host. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index db95487..c64934c 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -1195,10 +1195,15 @@ int netvsc_poll(struct napi_struct *napi, int budget) nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc); } - /* If send of pending receive completions suceeded - * and did not exhaust NAPI budget + /* if ring is empty, signal host */ + if (!nvchan->desc) + hv_pkt_iter_close(channel); + + /* If send of pending receive completions suceeded + * and did not exhaust NAPI budget this time * and not doing busy poll - * then reschedule if more data has arrived from host + * then re-enable host interrupts + * and reschedule if ring is not empty. */ if (send_recv_completions(nvchan) == 0 && work_done < budget && -- 2.7.4