Re: thousands of kworker processes with 4.7.x and 4.8-rc*

From: Mike Galbraith
Date: Sun Sep 25 2016 - 14:22:40 EST


On Sun, 2016-09-25 at 19:21 +0200, Mike Galbraith wrote:
> On Sun, 2016-09-25 at 21:40 +0900, Tomasz Chmielewski wrote:
>
> > The problem is the allocator.
> >
> > -CONFIG_SLUB=y
> > +CONFIG_SLAB=y
> >
> >
> > With SLUB, I'm getting a handful of kworker processes, as expected.
> >
> > With SLAB, I'm getting thousands of kworker processes.
> >
> >
> > Not sure if that's expected behaviour or not.
>
> I seriously doubt 1500+ kworkers piling up is expected.
>
> 4.7.0-rc4 47
> 4.7.0-rc5 1592
>
> Presuming you didn't switch to SLAB and/or change userspace all around
> while testing, that would still indicate a kernel regression lurking
> between rc4 and rc5.

Nevermind, seems config change was how you met the thing.

FWIW, I turned on SLAB with a distro config here, and see no such
behavior. If I could reproduce, I'd take the busted config back to
older kernels.

-Mike