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

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
...@@ -30,6 +30,7 @@ ...@@ -30,6 +30,7 @@
#include <linux/if_ether.h> #include <linux/if_ether.h>
#include <linux/vmalloc.h> #include <linux/vmalloc.h>
#include <linux/rtnetlink.h> #include <linux/rtnetlink.h>
#include <linux/prefetch.h>
#include <asm/sync_bitops.h> #include <asm/sync_bitops.h>
...@@ -1265,10 +1266,15 @@ int netvsc_poll(struct napi_struct *napi, int budget) ...@@ -1265,10 +1266,15 @@ int netvsc_poll(struct napi_struct *napi, int budget)
void netvsc_channel_cb(void *context) void netvsc_channel_cb(void *context)
{ {
struct netvsc_channel *nvchan = 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)) { if (napi_schedule_prep(&nvchan->napi)) {
/* disable interupts from host */ /* disable interupts from host */
hv_begin_read(&nvchan->channel->inbound); hv_begin_read(rbi);
__napi_schedule(&nvchan->napi); __napi_schedule(&nvchan->napi);
} }
......
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