[PATCH net-next v5 5/9] xen-netback: Add stat counters for zerocopy
From: Zoltan Kiss <hidden>
Date: 2014-01-20 21:24:57
Also in:
lkml, xen-devel
Subsystem:
networking drivers, the rest, xen network backend driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Wei Liu, Paul Durrant
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. Signed-off-by: Zoltan Kiss <redacted> --- drivers/net/xen-netback/common.h | 3 +++ drivers/net/xen-netback/interface.c | 15 +++++++++++++++ drivers/net/xen-netback/netback.c | 9 ++++++++- 3 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 419e63c..e3c28ff 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h@@ -155,6 +155,9 @@ struct xenvif { /* Statistics */ unsigned long rx_gso_checksum_fixup; + unsigned long tx_zerocopy_sent; + unsigned long tx_zerocopy_success; + unsigned long tx_zerocopy_fail; /* Miscellaneous private stuff. */ struct net_device *dev;
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index af5216f..75fe683 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c@@ -239,6 +239,21 @@ static const struct xenvif_stat { "rx_gso_checksum_fixup", offsetof(struct xenvif, rx_gso_checksum_fixup) }, + /* If (sent != success + fail), there are probably packets never + * freed up properly! + */ + { + "tx_zerocopy_sent", + offsetof(struct xenvif, tx_zerocopy_sent), + }, + { + "tx_zerocopy_success", + offsetof(struct xenvif, tx_zerocopy_success), + }, + { + "tx_zerocopy_fail", + offsetof(struct xenvif, tx_zerocopy_fail) + }, }; static int xenvif_get_sset_count(struct net_device *dev, int string_set)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index a1b03e4..e2dd565 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c@@ -1611,8 +1611,10 @@ static int xenvif_tx_submit(struct xenvif *vif, int budget) * 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); }
@@ -1645,6 +1647,11 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success) napi_schedule(&vif->napi); } while (ubuf); spin_unlock_irqrestore(&vif->dealloc_lock, flags); + + if (likely(zerocopy_success)) + vif->tx_zerocopy_success++; + else + vif->tx_zerocopy_fail++; } static inline void xenvif_tx_action_dealloc(struct xenvif *vif)