@@ -30,6 +30,7 @@
#include <linux/if_ether.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
+#include <linux/prefetch.h>
#include <asm/sync_bitops.h>
@@ -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);
}
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 <sthemmin@microsoft.com> --- drivers/net/hyperv/netvsc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)