Re: [patch 21/21] slab defrag: Obsolete SLAB

From: Christoph Lameter
Date: Fri May 16 2008 - 15:07:17 EST


On Thu, 15 May 2008, Matthew Wilcox wrote:

> On Thu, May 15, 2008 at 12:09:06PM -0700, Christoph Lameter wrote:
> > Assumptions may be the issue. My own "reproducer" for remote frees is
> > available from my git tree and I usually prefer to run my own. We
>
> No doubt you prefer to run a test which fails to show a problem with
> your code. How about you try running a test which does show a problem?

The test was designed to show the worst case effect of the additional
atomic op and it does its job. Look at the tests branch of my vm git tree.

> > There is no way of zeroing the counters. Run slabinfo -AD after the
> > test application has been running for awhile. If you want a differential
> > then you have to take two datapoints.
>
> Is a differential interesting to you?

Depends on how much other stuff is going on before.

>
> > > Otherwise I'll get something wrong and these numbers will be useless to
> > > you. Or that's what you'll claim anyway.
> >
> > No. I guess I will end up with a lot of guess work of what is going on on
> > the system since the information is limited for some reason.
>
> They're your statistics. Tell me what you need.

The output of slabinfo -AD....


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