Commit 0e59a4a5 authored by Zoltan Kiss's avatar Zoltan Kiss Committed by David S. Miller

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: default avatarZoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 869b9b19
......@@ -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;
}
}
......
......@@ -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,
......
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