On 11/04/2017 07:28 PM, Tetsuo Handa wrote:
Wei Wang wrote:
On 11/03/2017 07:25 PM, Tetsuo Handa wrote:
If this is inside vb->balloon_lock mutex (isn't this?), xb_set_page() must not
use __GFP_DIRECT_RECLAIM allocation, for leak_balloon_sg_oom() will be blocked
on vb->balloon_lock mutex.
OK. Since the preload() doesn't need too much memory (< 4K in total),
how about GFP_NOWAIT here?
Maybe GFP_NOWAIT | __GFP_NOWARN ?
Sounds good to me. I also plan to move "xb_set_page()" under mutex_lock,
that is,
fill_balloon()
{
...
mutex_lock(&vb->balloon_lock);
vb->num_pfns = 0;
while ((page = balloon_page_pop(&pages))) {
==> xb_set_page(..,page,..);
balloon_page_enqueue(&vb->vb_dev_info, page);
...
}
As explained in the xbitmap patch, we need the lock to avoid concurrent
access to the bitmap.
Best,
Wei
