Re: Vanilla-Kernel 3 - page allocation failure

[Philipp Herz - Profihost AG <p.herz@profihost.ag>]

> On Tue, 18 Oct 2011 08:51:54 PDT, Andi Kleen said:
>> Philipp Herz - Profihost AG<p.herz@profihost.ag>  writes:
>>
>>> After updating kernel (x86_64) to stable version 3 there are a few
>>> messages appearing in the kernel log such as
>>>
>>> kworker/0:1: page allocation failure: order:1, mode:0x20
>>> mysql: page allocation failure: order:1, mode:0x20
>>> php5: page allocation failure: order:1, mode:0x20
>>
>> You just ran out of memory.
>
> I read it as "Why is this happening when the previous kernel didn't have
> this issue?", which is a *much* more complicated question...

Exactly, that was the intention of my post.

It would me nice to know, if these messages do require to focus on 
memory statitics?

Looking at our monitoring data, the system does have enough memory 
available.

How do processes get effected, when they are running into situations 
where kernel memory manager tells them about "page allocation failure"?

Is it just meant to be a warning/debugging message new to current kernel 
version 3?

How can we solve the situation? Getting rid of these message, by

- just suppressing
- increasing system's memory
- change kernel and/or kernel runtime config

?

Kind regards,
Philipp