Re: Vanilla-Kernel 3 - page allocation failure

From: Philipp Herz - Profihost AG
Date: Fri Oct 21 2011 - 02:37:15 EST


On Tue, 18 Oct 2011 08:51:54 PDT, Andi Kleen said:
Philipp Herz - Profihost AG<p.herz@xxxxxxxxxxxx> 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
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