From 43bf99ce009de710b68473480a611f3b5ddd11d5 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Mon, 24 Jul 2017 10:57:27 -0700 Subject: [PATCH] netvsc: prefetch the first incoming ring element In interrupt handler, prefetch the first incoming ring element so that it is in cache by the time NAPI poll gets to it. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 0a9d9feedc3f..06f39a99da7c 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -30,6 +30,7 @@ #include #include #include +#include #include @@ -1265,10 +1266,15 @@ int netvsc_poll(struct napi_struct *napi, int budget) void netvsc_channel_cb(void *context) { struct netvsc_channel *nvchan = context; + struct vmbus_channel *channel = nvchan->channel; + struct hv_ring_buffer_info *rbi = &channel->inbound; + + /* preload first vmpacket descriptor */ + prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index); if (napi_schedule_prep(&nvchan->napi)) { /* disable interupts from host */ - hv_begin_read(&nvchan->channel->inbound); + hv_begin_read(rbi); __napi_schedule(&nvchan->napi); } -- 2.20.1