Re: [PATCH 1/6] kmod: add dynamic max concurrent thread count

Dmitry Torokhov
2017-05-25T18:27:03Z

On Thu, May 25, 2017 at 08:06:03PM +0200, Luis R. Rodriguez wrote:
> On Thu, May 25, 2017 at 10:38:40AM -0700, Luis R. Rodriguez wrote:
> > On Thu, May 25, 2017 at 10:30 AM, Dmitry Torokhov
> > > There is
> > > no slippery slope for systems to move away, no need to backport
> > > anything. We seem to agree that a better solution is possible (throttle
> > > number of concurrently running modprobes without killing requesters),
> > > and with that solution the band-aid will no longer be needed.
> > >
> > > So please implement and post the proper fix for the issue.
> >
> > Alright, will do away with this patch and just go for the jugular of the issue.
>
> I gave this some more thought, even if we go with the throttling right away in
> practice you'll end up with a dmesg notice of a throttle kicking in once you *do*

So remove it. The warning was meaningful when we rejected requests, now
it is not.

> reach this. We are forcing only 50 concurrent threads and making this a static
> limit with no good reason than 2.3.38 days evaluation from 16 years ago (2000).
> If we throttle we are going to throttle with a 2.3.38 days limit. And you
> advocate that ?

Yes. Can you give me reason why slamming the system with more than 50
modprobes is a good idea in 4.12 days? Does the increased limit
decreases boot time? By how much?

--
Dmitry