Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 43bf99ce authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

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: default avatarStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 37b9dfa0

drivers/net/hyperv/netvsc.c

+7 −1
Original line number Diff line number Diff line
@@ -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);

	}