Re: Odd kswapd behaviour after suspending in 2.6.11-rc1

Nick Piggin
2005-01-15T10:40:19Z

Nigel Cunningham wrote:
> Hi Nick and Bernard.
>
> On Sat, 2005-01-15 at 21:16, Nick Piggin wrote:
>
>>OK I think the problem is due to swsusp allocating a very large
>>chunk of memory before suspending. After resuming, kswapd is more
>>or less in the same state and tries a bit too hard to free things.
>
>
> I'm not sure about this theory. The normal case will be that all
> allocations (maybe one or two order 1 or order 2 allocations if I've
> forgotten something) are order 0 and processes are thawed after we've
> freed all the memory we were using. Could that still trigger kswapd?
>

I've seen try to do order 8 allocations or something almost as
ridiculous. Atomic too.

Well, correction, I've seen _reports_. Never tried swsusp myself.

I don't think a few order 0 and 1 allocations would do any harm
because otherwise every man and his dog would be having problems.

>
>>Thanks for the report... I'll come up with something for you to try
>>in the next day or so.
>
>
> I'm flying to America on Monday, but I'll try to keep up with the
> progress in this and do anything I can to help.
>

It is basically a problem with one of my patches. I should be able
to fix it (although fixing swsusp would be nice too :) ).

Thanks,
Nick