Re: [PATCH RFC tip/core/rcu] Make SRCU be once again optional

From: Paul E. McKenney
Date: Sat Jun 03 2017 - 16:44:03 EST


On Sat, Jun 03, 2017 at 01:18:43AM -0400, Nicolas Pitre wrote:
> On Fri, 2 Jun 2017, Paul E. McKenney wrote:
>
> > On Fri, May 12, 2017 at 12:10:05PM -0700, Paul E. McKenney wrote:
> > > On Fri, May 12, 2017 at 02:59:48PM -0400, Nicolas Pitre wrote:
> > > > On Fri, 12 May 2017, Paul E. McKenney wrote:
> >
> > [ . . . ]
> >
> > > > No. "Available in mainline" is the name of the game for all I do. If it
> > > > can't be made acceptable for mainline then it basically has no chance of
> > > > gaining traction and becoming generally useful. My approach is therefore
> > > > to always find solutions that can be maintained upstream and contributed
> > > > to with minimal fuss by anyone.
> > >
> > > OK, then wish me luck. ;-)
> >
> > And still quite a bit of back and forth. How are things with tty?
> >
> > One question that came up -- what sort of SoCs are you targeting?
> > A number of people are insisting that smartphone SoCs with 256M DRAM
> > are the minimal systems of the future. This seems unlikely to me,
> > given the potential for extremely cheap SoCs with EDRAM or some such,
> > but figured I should ask what you are targeting.
>
> I'm targetting 256 *kilobytes* of RAM. Most likely SRAM. That's not for
> smart phones but really cheap IoT devices. That's the next area for
> (trimmed down) Linux to conquer. Example targets are STM32 chips.
>
> Please see the following for the rationale and how to get there:
>
> https://lwn.net/Articles/721074/
>
> http://www.mail-archive.com/search?l=mid&q=alpine.LFD.2.20.1703241215540.2304%40knanqh.ubzr

Ah, thank you for the reminder. I did read that article, but somehow
got a few megabytes stuck in my head instead of the correct quarter meg.

Anyway, don't look now, but Tiny {S,}RCU just might live on, for a bit
longer, anyway.

Thanx, Paul