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

David Hildenbrand
2019-08-21T16:29:13Z

On 21.08.19 18:23, Nadav Amit wrote:
>> 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.
>

ratelimit would make sense :)

And yes, this would certainly be nicer.

--

Thanks,

David / dhildenb