From 0e59a4a553df312b5308c75085f7f02b12680d12 Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Mon, 24 Mar 2014 23:59:50 +0000 Subject: [PATCH] xen-netback: Non-functional follow-up patch for grant mapping series Ian made some late comments about the grant mapping series, I incorporated the non-functional outcomes into this patch: - typo fixes in a comment of xenvif_free(), and add another one there as well - typo fix for comment of rx_drain_timeout_msecs - remove stale comment before calling xenvif_grant_handle_reset() Signed-off-by: Zoltan Kiss Signed-off-by: David S. Miller --- drivers/net/xen-netback/interface.c | 13 ++++++++++--- drivers/net/xen-netback/netback.c | 4 +--- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index e71fb1ac5c4d..cdc298e3b747 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -574,15 +574,15 @@ void xenvif_disconnect(struct xenvif *vif) void xenvif_free(struct xenvif *vif) { int i, unmap_timeout = 0; - /* Here we want to avoid timeout messages if an skb can be legitimatly - * stucked somewhere else. Realisticly this could be an another vif's + /* Here we want to avoid timeout messages if an skb can be legitimately + * stuck somewhere else. Realistically this could be an another vif's * internal or QDisc queue. That another vif also has this * rx_drain_timeout_msecs timeout, but the timer only ditches the * internal queue. After that, the QDisc queue can put in worst case * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's * internal queue, so we need several rounds of such timeouts until we * can be sure that no another vif should have skb's from us. We are - * not sending more skb's, so newly stucked packets are not interesting + * not sending more skb's, so newly stuck packets are not interesting * for us here. */ unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) * @@ -597,6 +597,13 @@ void xenvif_free(struct xenvif *vif) netdev_err(vif->dev, "Page still granted! Index: %x\n", i); + /* If there are still unmapped pages, reset the loop to + * start checking again. We shouldn't exit here until + * dealloc thread and NAPI instance release all the + * pages. If a kernel bug causes the skbs to stall + * somewhere, the interface cannot be brought down + * properly. + */ i = -1; } } diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 5d2dd1d54173..d3172fe0306f 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -56,7 +56,7 @@ bool separate_tx_rx_irq = 1; module_param(separate_tx_rx_irq, bool, 0644); /* When guest ring is filled up, qdisc queues the packets for us, but we have - * to timeout them, otherwise other guests' packets can get stucked there + * to timeout them, otherwise other guests' packets can get stuck there */ unsigned int rx_drain_timeout_msecs = 10000; module_param(rx_drain_timeout_msecs, uint, 0444); @@ -1545,7 +1545,6 @@ static inline void xenvif_tx_dealloc_action(struct xenvif *vif) idx_to_kaddr(vif, pending_idx), GNTMAP_host_map, vif->grant_tx_handle[pending_idx]); - /* Btw. already unmapped? */ xenvif_grant_handle_reset(vif, pending_idx); ++gop; } @@ -1678,7 +1677,6 @@ void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx) idx_to_kaddr(vif, pending_idx), GNTMAP_host_map, vif->grant_tx_handle[pending_idx]); - /* Btw. already unmapped? */ xenvif_grant_handle_reset(vif, pending_idx); ret = gnttab_unmap_refs(&tx_unmap_op, NULL, -- 2.11.0