Re: [PATCH RFC] s390/sclp: pass timeout as HZ independent value

Nicholas Mc Guire
2015-05-29T14:43:26Z

On Fri, 29 May 2015, Heiko Carstens wrote:

> On Fri, May 29, 2015 at 04:16:46PM +0200, Nicholas Mc Guire wrote:
> > On Fri, 29 May 2015, Michael Holzheu wrote:
> >
> > > On Fri, 29 May 2015 13:49:36 +0200
> > > Nicholas Mc Guire <der.herr@hofr.at> wrote:
> > >
> > > > On Fri, 29 May 2015, Heiko Carstens wrote:
> > > >
> > > > > On Fri, May 29, 2015 at 11:51:54AM +0200, Nicholas Mc Guire wrote:
> > > > > > On Fri, 29 May 2015, Heiko Carstens wrote:
> > > > > > > Yes, the orginal code seems to be broken. Since I've no idea what the intended
> > > > > > > timeout value should be, let's simply ask Michael, who wrote this code eight
> > > > > > > years ago ;)
> > > > > > > While these lines get touched anyway, it would make sense to use
> > > > > > > schedule_timeout_interruptible() instead, and get rid of set_current_state().
> > > > > > >
> > > > > > Well that is not really equivalent
> > > > > > schedule_timeout_interruptible() is doing
> > > > > > __set_current_state not set_current_state
> > > > > > so that would drop the mb() and no WRITE_ONCE()
> > > > >
> > > > > And how does that matter in this case?
> > > > >
> > > > I do not know - did not look into it - in any case
> > > > its not a 1:1 API consolidation that all I wanted to point out
> > > > before changing anything.
> > >
> > > I agree, 1:1 consolidation is better here.
> > >
> > > But I would like to remove the SDIAS_SLEEP_TICKS define and just
> > > use HZ / 2 in schedule_timeout(). Could you please resend the
> > > updated patch? We will then add it to our tree.
> > >
> > will do that.
> >
> > I was compile testing with x86_64-gcc-4.6.3-nolibc_s390x-linux.tar.bz2
> > https://www.kernel.org/pub/tools/crosstool/
> > but that fails for all of the available defconfigs in arch/s390/configs
> > would you have a pointer to a toolchain that can be used for compile testing ?
>
> Just change processor type to "IBM System z10", or manually edit .config, and
> change CONFIG_MARCH_ZEC12 to be disabled and CONFIG_MARCH_Z10 instead to yes.
> The same applies to CONFIG_MARCH_ZEC12_TUNE.
> However we will accept the patch also without compile test.
>
yup - thats working - thanks !

thx!
hofrat