v4.9, 4.4-final: 28 bioset threads on small notebook, 36 threads on cellphone

From: Pavel Machek
Date: Mon Feb 06 2017 - 07:53:17 EST


On Sat 2016-02-20 21:04:32, Pavel Machek wrote:
> Hi!
>
> > > > > > I know it is normal to spawn 8 threads for every single function,
> > > > > ...
> > > > > > but 28 threads?
> > > > > >
> > > > > > root 974 0.0 0.0 0 0 ? S< Dec08 0:00 [bioset]
> > > > > ...
> > > > >
> > > > > How many physical block devices do you have?
> > > > >
> > > > > DM is doing its part to not contribute to this:
> > > > > dbba42d8a ("dm: eliminate unused "bioset" process for each bio-based DM device")
> > > > >
> > > > > (but yeah, all these extra 'bioset' threads aren't ideal)
> > > >
> > > > Still there in 4.4-final.
> > >
> > > ...and still there in 4.5-rc4 :-(.
> >
> > You're directing this concern to the wrong person.
> >
> > I already told you DM is _not_ contributing any extra "bioset" threads
> > (ever since commit dbba42d8a).
>
> Well, sorry about that. Note that l-k is on the cc list, so hopefully
> the right person sees it too.
>
> Ok, let me check... it seems that
> 54efd50bfd873e2dbf784e0b21a8027ba4299a3e is responsible, thus Kent
> Overstreet <kent.overstreet@xxxxxxxxx> is to blame.
>
> Um, and you acked the patch, so you are partly responsible.

Still there on v4.9, 36 threads on nokia n900 cellphone.

So.. what needs to be done there?
Pavel

--
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