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

From: David Hildenbrand
Date: Wed Aug 21 2019 - 12:29:14 EST

On 21.08.19 18:23, Nadav Amit wrote:
>> On Aug 21, 2019, at 9:05 AM, David Hildenbrand <david@xxxxxxxxxx> 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(âBalloon memory allocation failedâ);
> Or even something more informative? This would surely be less intimidating
> for common users.

ratelimit would make sense :)

And yes, this would certainly be nicer.



David / dhildenb