I think it's worth trying GFP_NOFAIL just to see what happens.
The correct fix is probably to wrap the page_alloc in a loop that
retries a few times, maybe something like:
unsigned long start = jiffies;
while( (pl->page = alloc_page(GFP_KERNEL)) == NULL &&
jiffies - start < 5*HZ )
blk_congestion_wait(WRITE, HZ/5);
It's likely not helped by the fact the network driver has big
allocation spikes periodically when it refills the packet receive
ring. I'll check in something to smooth out those allocations...
-- Keir
28 messages in com.xensource.lists.xen-develRe: [Xen-devel] LVM Snapshot Troubles 
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