Re: [RFC PATCH 0/3] Fix SLQB on memoryless configurations V2

Mel Gorman
2009-09-22T12:55:42Z

On Tue, Sep 22, 2009 at 10:33:11AM +0530, Sachin Sant wrote:
> Mel Gorman wrote:
>> On Mon, Sep 21, 2009 at 01:54:12PM -0400, Christoph Lameter wrote:
>>
>>> Lets just keep SLQB back until the basic issues with memoryless nodes are
>>> resolved.
>>>
>>
>> It's not even super-clear that the memoryless nodes issues are entirely
>> related to SLQB. Sachin for example says that there was a stall issue
>> with memoryless nodes that could be triggered without SLQB. Sachin, is
>> that still accurate?
>>
> I think there are two different problems that we are dealing with.
>
> First one is the SLQB not working on a ppc64 box which seems to be specific
> to only one machine and i haven't seen that on other power boxes.The patches
> that you have posted seems to allow the box to boot, but eventually it hits
> the stall issue(related to percpu dynamic allocator not working on ppc64),
> which is the second problem we are dealing with.
>

Ok, I've sent out V3 of this. It's only a partial fix but it's about as
far as it can be brought until the other difficulties are resolved.

> The stall issue seems to be much more critical as it is affecting almost
> all of the power boxes that i have tested with (4 in all).
> This issue is seen with Linus tree as well and was first seen with
> 2.6.31-git5 (0cb583fd..)
>
> The stall issue was reported here:
> http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-September/075791.html
>

Can you bisect this please?

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab