[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [PATCH net] xen-netback: fix abuse of napi budget



netback seemed to be somewhat confused about the napi budget parameter and
basically ignored it. This patch fixes that, properly limiting the work done
in each poll.

Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
---
 drivers/net/xen-netback/netback.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/xen-netback/netback.c 
b/drivers/net/xen-netback/netback.c
index 43341b8..83b4e5b 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1351,14 +1351,15 @@ static bool tx_credit_exceeded(struct xenvif *vif, 
unsigned size)
        return false;
 }
 
-static unsigned xenvif_tx_build_gops(struct xenvif *vif)
+static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
 {
        struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop;
        struct sk_buff *skb;
        int ret;
 
        while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
-               < MAX_PENDING_REQS)) {
+               < MAX_PENDING_REQS) &&
+              (skb_queue_len(&vif->tx_queue) < budget)) {
                struct xen_netif_tx_request txreq;
                struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
                struct page *page;
@@ -1520,14 +1521,13 @@ static unsigned xenvif_tx_build_gops(struct xenvif *vif)
 }
 
 
-static int xenvif_tx_submit(struct xenvif *vif, int budget)
+static int xenvif_tx_submit(struct xenvif *vif)
 {
        struct gnttab_copy *gop = vif->tx_copy_ops;
        struct sk_buff *skb;
        int work_done = 0;
 
-       while (work_done < budget &&
-              (skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
+       while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
                struct xen_netif_tx_request *txp;
                u16 pending_idx;
                unsigned data_len;
@@ -1602,14 +1602,14 @@ int xenvif_tx_action(struct xenvif *vif, int budget)
        if (unlikely(!tx_work_todo(vif)))
                return 0;
 
-       nr_gops = xenvif_tx_build_gops(vif);
+       nr_gops = xenvif_tx_build_gops(vif, budget);
 
        if (nr_gops == 0)
                return 0;
 
        gnttab_batch_copy(vif->tx_copy_ops, nr_gops);
 
-       work_done = xenvif_tx_submit(vif, nr_gops);
+       work_done = xenvif_tx_submit(vif);
 
        return work_done;
 }
-- 
1.7.10.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.