Re: [PATCH net-next v3 1/9] xen-netback: Introduce TX grant map definitions

From: Zoltan Kiss
Date: Thu Jan 09 2014 - 14:53:21 EST


On 09/01/14 15:30, Wei Liu wrote:
On Wed, Jan 08, 2014 at 12:10:10AM +0000, Zoltan Kiss wrote:
v3:
- fix comment in xenvif_tx_dealloc_action()
- call unmap hypercall directly instead of gnttab_unmap_refs(), which does
unnecessary m2p_override. Also remove pages_to_[un]map members

Is it worthy to have another function call
gnttab_unmap_refs_no_m2p_override in Xen core driver, or just add a
parameter to control wether we need to touch m2p_override? I *think* it
will benefit block driver as well?

(CC Roger and David for input)

Yep, it worth, but let's make it a different patch

--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -771,6 +771,19 @@ static struct page *xenvif_alloc_page(struct xenvif *vif,
return page;
}

+static inline void xenvif_tx_create_gop(struct xenvif *vif, u16 pending_idx,
+ struct xen_netif_tx_request *txp,
+ struct gnttab_map_grant_ref *gop)

Indentation.
I fixed it and the later ones up, hopefully I haven't missed anything.


+
+ spin_lock_irqsave(&vif->dealloc_lock, flags);
+ do {
+ pending_idx = ubuf->desc;
+ ubuf = (struct ubuf_info *) ubuf->ctx;
+ index = pending_index(vif->dealloc_prod);
+ vif->dealloc_ring[index] = pending_idx;
+ /* Sync with xenvif_tx_action_dealloc:

xenvif_tx_dealloc_action I suppose.
Yes.

+ /* Already unmapped? */
+ if (vif->grant_tx_handle[pending_idx] ==
+ NETBACK_INVALID_HANDLE) {
+ netdev_err(vif->dev,
+ "Trying to unmap invalid handle! "
+ "pending_idx: %x\n", pending_idx);
+ continue;

You seemed to miss the BUG_ON we discussed?

See thread starting <52AF1A84.3090304@xxxxxxxxxx>.
Indeed, despite I wrote it in the version history :)


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