From 1bb332af4cd889e4b64dacbf4a793ceb3a70445d Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Thu, 6 Mar 2014 21:48:28 +0000 Subject: 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 Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/net/xen-netback/netback.c') 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) -- cgit v1.2.3-59-g8ed1b