Re: swapping and the value of /proc/sys/vm/swappiness

Con Kolivas
2004-09-07T01:35:19Z

Marcelo Tosatti writes:

> On Tue, Sep 07, 2004 at 09:34:20AM +1000, Con Kolivas wrote:
>> Andrew Morton writes:
>>
>> >Con Kolivas <kernel@kolivas.org> wrote:
>> >>
>> >>> A scan of the change logs for swappiness related changes shows nothing
>> >>that > might explain these changes. My question is: "Is this change in
>> >> behavior
>> >> > deliberate, or just a side effect of other changes that were made in
>> >> the vm?" > and "What kind of swappiness behavior might I expect to find
>> >> in future kernels?".
>> >>
>> >> The change was not deliberate but there have been some other people
>> >> report significant changes in the swappiness behaviour as well (see
>> >> archives). It has usually been of the increased swapping variety lately.
>> >> It has been annoying enough to the bleeding edge desktop users for a
>> >> swag of out-of-tree hacks to start appearing (like mine).
>> >
>> >All of which is largely wasted effort. It would be much more useful to get
>> >down and identify which patch actually caused the behavioural change.
>>
>> I don't disagree. Is there anyone who has the time and is willing to do the
>> regression testing? This is a general appeal to the mailing list.
>
> Hi kernel fellows,
>
> I volunteer. I'll try something tomorrow to compare swappiness of older kernels like
> 2.6.5 and 2.6.6, which were fine on SGI's Altix tests, up to current newer kernels
> (on small memory boxes of course).
>
> Someone needs to write a vmstat-like tool to parse /proc/vmstat.
> The statistics in there allows us to watch the behaviour of VM
> page reclaim code.
>
> Con, if you could compile a list of reports we would be very grateful.

Apart from lots of "soft" reports I've been getting, the most obvious one
recently on the mailing list is this:

http://marc.theaimsgroup.com/?l=linux-kernel&m=109237941331221&w=2

and no, I'm not referring to this thread because he tried one of my patches;
that's an old patch that I'm not even pushing any more.

Cheers,
Con