Re: [PATCH net-next] xen-netback: Follow-up patch for grant mapping series
From: Zoltan Kiss
Date: Fri Mar 21 2014 - 15:43:37 EST
On 21/03/14 09:41, Ian Campbell wrote:
On Thu, 2014-03-20 at 19:32 +0000, Zoltan Kiss wrote:
Ian made some late comments about the grant mapping series, I incorporated the
outcomes into this patch. Additional comments, refactoring etc.
I don't know how davem feels about merging these kinds of thing into one
patch but from my point of view the least thing to do is to enumerate
the cleanups -- so that people can verify that the patch does infact do
exactly what it says it does, no more, no less.
Ok, I'll make a detailed list in the commit message about what are the
changes, and fix up the typos you mentioned below.
Signed-off-by: Zoltan Kiss <zoltan.kiss@xxxxxxxxxx>
---
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 6837bfc..fa19538 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -576,15 +576,15 @@ 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) *
@@ -599,6 +599,13 @@ 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 mchecking again. We shouldn't exit here until
"checking"
+ * dealloc thread and NAPI instance release all the
+ * pages. If a kernel bug cause the skbs stall
"causes the skbs to stall"
+ * somewhere, the interface couldn't be brought down
+ * properly.
I'm not sure what you are saying here exactly. Perhaps you means
s/couldn't/cannot/?
+ */
i = -1;
}
}
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 1c336f6..0e46184b 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);
@@ -99,6 +99,9 @@ static inline unsigned long idx_to_kaddr(struct xenvif *vif,
return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx));
}
+#define callback_param(vif, pending_idx) \
+ (vif->pending_tx_info[pending_idx].callback_struct)
+
/* Find the containing VIF's structure from a pointer in pending_tx_info array
*/
static inline struct xenvif* ubuf_to_vif(struct ubuf_info *ubuf)
@@ -1025,12 +1028,12 @@ static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
/* If this is not the first frag, chain it to the previous*/
if (unlikely(prev_pending_idx == INVALID_PENDING_IDX))
skb_shinfo(skb)->destructor_arg =
- &vif->pending_tx_info[pending_idx].callback_struct;
+ &callback_param(vif, pending_idx);
else if (likely(pending_idx != prev_pending_idx))
- vif->pending_tx_info[prev_pending_idx].callback_struct.ctx =
- &(vif->pending_tx_info[pending_idx].callback_struct);
+ callback_param(vif, prev_pending_idx).ctx =
+ &callback_param(vif, pending_idx);
- vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
+ callback_param(vif, pending_idx).ctx = NULL;
prev_pending_idx = pending_idx;
txp = &vif->pending_tx_info[pending_idx].req;
@@ -1400,13 +1403,13 @@ static int xenvif_tx_submit(struct xenvif *vif)
memcpy(skb->data,
(void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
data_len);
- vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
+ callback_param(vif, pending_idx).ctx = NULL;
if (data_len < txp->size) {
/* Append the packet payload as a fragment. */
txp->offset += data_len;
txp->size -= data_len;
skb_shinfo(skb)->destructor_arg =
- &vif->pending_tx_info[pending_idx].callback_struct;
+ &callback_param(vif, pending_idx);
} else {
/* Schedule a response immediately. */
xenvif_idx_unmap(vif, pending_idx);
@@ -1550,7 +1553,6 @@ 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;
}
@@ -1683,12 +1685,20 @@ 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,
&vif->mmap_pages[pending_idx], 1);
- BUG_ON(ret);
+ if (ret) {
+ netdev_err(vif->dev,
+ "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: %x status: %d\n",
+ ret,
+ pending_idx,
+ tx_unmap_op.host_addr,
+ tx_unmap_op.handle,
+ tx_unmap_op.status);
+ BUG();
+ }
xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
}
--
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