Re: [PATCH] mm/balloon_compaction: suppress allocation warnings

Nadav Amit
2019-08-21T16:23:31Z

> On Aug 21, 2019, at 9:05 AM, David Hildenbrand <david@redhat.com> wrote:
>
> On 20.08.19 11:16, Nadav Amit wrote:
>> There is no reason to print warnings when balloon page allocation fails,
>> as they are expected and can be handled gracefully. Since VMware
>> balloon now uses balloon-compaction infrastructure, and suppressed these
>> warnings before, it is also beneficial to suppress these warnings to
>> keep the same behavior that the balloon had before.
>
> I am not sure if that's a good idea. The allocation warnings are usually
> the only trace of "the user/admin did something bad because he/she tried
> to inflate the balloon to an unsafe value". Believe me, I processed a
> couple of such bugreports related to virtio-balloon and the warning were
> very helpful for that.

Ok, so a message is needed, but does it have to be a generic frightening
warning?

How about using __GFP_NOWARN, and if allocation do something like:

pr_warn(“Balloon memory allocation failed”);

Or even something more informative? This would surely be less intimidating
for common users.