Re: [PATCH v1 2/3] virtio-balloon: deflate up to oom_pages on OOM

From: Tetsuo Handa
Date: Sun Oct 22 2017 - 00:11:38 EST


Michael S. Tsirkin wrote:
> On Fri, Oct 20, 2017 at 07:54:25PM +0800, Wei Wang wrote:
> > The current implementation only deflates 256 pages even when a user
> > specifies more than that via the oom_pages module param. This patch
> > enables the deflating of up to oom_pages pages if there are enough
> > inflated pages.
>
> This seems reasonable. Does this by itself help?

At least

> > - num_freed_pages = leak_balloon(vb, oom_pages);
> > +
> > + /* Don't deflate more than the number of inflated pages */
> > + while (npages && atomic64_read(&vb->num_pages))
> > + npages -= leak_balloon(vb, npages);

don't we need to abort if leak_balloon() returned 0 for some reason?