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| author | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2003-07-30 21:27:29 +0000 |
|---|---|---|
| committer | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2003-07-30 21:27:29 +0000 |
| commit | f7463a99139aaa01df0345830b79e48c0ee89fab (patch) | |
| tree | 50716f78559189958bc4fc5d95a7ce428508477d /xen | |
| parent | 2a1d0b3f0233b00c23f0b3020511fe25d0b31607 (diff) | |
| download | xen-f7463a99139aaa01df0345830b79e48c0ee89fab.tar.gz xen-f7463a99139aaa01df0345830b79e48c0ee89fab.tar.bz2 xen-f7463a99139aaa01df0345830b79e48c0ee89fab.zip | |
bitkeeper revision 1.387 (3f283841sxL_1BFf_Dks40SWU9PRqg)
dev.c:
Fix possible subtle race in new network tx code.
Diffstat (limited to 'xen')
| -rw-r--r-- | xen/net/dev.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/xen/net/dev.c b/xen/net/dev.c index b1a87ffb83..e9e965c7e9 100644 --- a/xen/net/dev.c +++ b/xen/net/dev.c @@ -836,6 +836,12 @@ static void tx_skb_release(struct sk_buff *skb) __make_tx_response(vif, skb->guest_id, RING_STATUS_OK); spin_unlock_irqrestore(&vif->tx_lock, flags); + /* + * Checks below must happen after the above response is posted. + * This avoids a possible race with a guest OS on another CPU. + */ + smp_rmb(); + if ( (vif->tx_cons == vif->tx_prod) && get_tx_bufs(vif) ) { add_to_net_schedule_list_tail(vif); |