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authorZoltan Kiss <zoltan.kiss@citrix.com>2014-03-06 21:48:28 +0000
committerDavid S. Miller <davem@davemloft.net>2014-03-07 15:56:35 -0500
commit1bb332af4cd889e4b64dacbf4a793ceb3a70445d (patch)
tree1aef36c3aa0f6366562e169fbfe7589190d9387e /drivers/net/xen-netback/netback.c
parentxen-netback: Remove old TX grant copy definitons and fix indentations (diff)
downloadlinux-dev-1bb332af4cd889e4b64dacbf4a793ceb3a70445d.tar.xz
linux-dev-1bb332af4cd889e4b64dacbf4a793ceb3a70445d.zip
xen-netback: Add stat counters for zerocopy
These counters help determine how often the buffers had to be copied. Also they help find out if packets are leaked, as if "sent != success + fail", there are probably packets never freed up properly. NOTE: if bisect brought you here, you should apply the series up until "xen-netback: Timeout packets in RX path", otherwise Windows guests can't work properly and malicious guests can block other guests by not releasing their sent packets. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--drivers/net/xen-netback/netback.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 46a75706cb78..3cb586357df7 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1323,8 +1323,10 @@ static int xenvif_tx_submit(struct xenvif *vif)
* do a skb_copy_ubufs while we are still in control of the
* skb. E.g. the __pskb_pull_tail earlier can do such thing.
*/
- if (skb_shinfo(skb)->destructor_arg)
+ if (skb_shinfo(skb)->destructor_arg) {
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ vif->tx_zerocopy_sent++;
+ }
netif_receive_skb(skb);
}
@@ -1364,6 +1366,11 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
napi_schedule(&vif->napi);
local_bh_enable();
}
+
+ if (likely(zerocopy_success))
+ vif->tx_zerocopy_success++;
+ else
+ vif->tx_zerocopy_fail++;
}
static inline void xenvif_tx_dealloc_action(struct xenvif *vif)