Re: linux-next: build failure after merge of the block tree

Geert Uytterhoeven
2020-07-15T15:22:25Z

Hi Jens,

> On Wed, Jul 15, 2020 at 5:08 PM Jens Axboe <axboe@kernel.dk> wrote:
> > On 7/15/20 3:24 AM, Geert Uytterhoeven wrote:
> > > On Wed, Jul 15, 2020 at 4:26 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> > >> After merging the block tree, today's linux-next build (arm
> > >> multi_v7_defconfig) failed like this:
> > >>
> > >> block/blk-timeout.c: In function 'blk_round_jiffies':
> > >> block/blk-timeout.c:96:14: error: 'CONFIG_HZ_ROUGH_MASK' undeclared (first use in this function)
> > >> 96 | return (j + CONFIG_HZ_ROUGH_MASK) + 1;
> > >> | ^~~~~~~~~~~~~~~~~~~~
> > >>
> > >> Caused by commit
> > >>
> > >> 91ba0f529364 ("block: relax jiffies rounding for timeouts")
> > >>
> > >> CONFIG_HZ_ROUGH_MASK is not defined for this build even though
> > >> CONFIG_HZ_100 is set. The arm arch does not include kernel/Kconfig.hz.
> > >>
> > >> I have reverted that commit for today.
> > >
> > > (as I don't have the original patch in my email, I'm commenting here)
> > >
> > > +config HZ_ROUGH_MASK
> > > + int
> > > + default 127 if HZ_100
> > > + default 255 if HZ_250 || HZ_300
> > > + default 1023 if HZ_1000
> > >
> > > What about other HZ_* values?
> >
> > Which other ones do we have?
>
> $ git grep "\<HZ_[0-9]" -- "*Kconf*"
> arch/alpha/Kconfig: default HZ_128 if ALPHA_QEMU
> arch/alpha/Kconfig: default HZ_1200 if ALPHA_RAWHIDE
> arch/alpha/Kconfig: default HZ_1024

And ARC allows you to enter any integer value:

config HZ
int "Timer Frequency"
default 100

So probably you want to derive something from the integer value itself.

Note that not all architectures include kernel/Kconfig.hz.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds