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

Re: [Xen-devel] [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy" series.



On 30/04/14 16:24, Eric Dumazet wrote:
On Wed, 2014-04-30 at 12:45 +0200, Sander Eikelenboom wrote:

This looks like skb->data_len is not properly set

(Small note :
alloc_page(GFP_ATOMIC|__GFP_COLD) should be a plain
alloc_page(GFP_ATOMIC) : We prefer a page that has been used recently to
avoid cache misses if possible.
)

This probably confuses skb_try_coalesce()

My guess is xenvif_get_requests() forgets to init nskb->len /
nskb->data_len for the skb that is attached to frag_list
xenvif_get_requests() calls alloc_skb() which inits these values to zero

So the "skb->data_len += nskb->len;" at line 1353 is probably a nop.


_______________________________________________
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®.