DM_CACHE_SMQ is experimental and enabled by default? (was: Re: dm cache: add stochastic-multi-queue (smq) policy)

DM_CACHE_SMQ is experimental and enabled by default? (was: Re: dm cache: add stochastic-multi-queue (smq) policy)

[Geert Uytterhoeven]

On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
<linux-kernel@vger.kernel.org> wrote:
> Gitweb:     http://git.kernel.org/linus/;a=commit;h=66a636356647a9be8885c2ce2948de126577698a
> Commit:     66a636356647a9be8885c2ce2948de126577698a
> Parent:     40775257b97e27305cf5c2425be7acaa6edee4ea
> Refname:    refs/heads/master
> Author:     Joe Thornber <ejt@redhat.com>
> AuthorDate: Fri May 15 15:33:34 2015 +0100
> Committer:  Mike Snitzer <snitzer@redhat.com>
> CommitDate: Thu Jun 11 17:12:59 2015 -0400
>
>     dm cache: add stochastic-multi-queue (smq) policy

> diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> index edcf4ab..b597273 100644
> --- a/drivers/md/Kconfig
> +++ b/drivers/md/Kconfig
> @@ -304,6 +304,18 @@ config DM_CACHE_MQ
>           This is meant to be a general purpose policy.  It prioritises
>           reads over writes.
>
> +config DM_CACHE_SMQ
> +       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
> +       depends on DM_CACHE
> +       default y

A feature cannot be "EXPERIMENTAL", and be enabled by default.
Please drop (at least) one of them.

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

Re: DM_CACHE_SMQ is experimental and enabled by default? (was: Re: dm cache: add stochastic-multi-queue (smq) policy)

[Mike Snitzer]

On Fri, Jun 26 2015 at  3:47am -0400,
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
> <linux-kernel@vger.kernel.org> wrote:
> > Gitweb:     http://git.kernel.org/linus/;a=commit;h=66a636356647a9be8885c2ce2948de126577698a
> > Commit:     66a636356647a9be8885c2ce2948de126577698a
> > Parent:     40775257b97e27305cf5c2425be7acaa6edee4ea
> > Refname:    refs/heads/master
> > Author:     Joe Thornber <ejt@redhat.com>
> > AuthorDate: Fri May 15 15:33:34 2015 +0100
> > Committer:  Mike Snitzer <snitzer@redhat.com>
> > CommitDate: Thu Jun 11 17:12:59 2015 -0400
> >
> >     dm cache: add stochastic-multi-queue (smq) policy
> 
> > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> > index edcf4ab..b597273 100644
> > --- a/drivers/md/Kconfig
> > +++ b/drivers/md/Kconfig
> > @@ -304,6 +304,18 @@ config DM_CACHE_MQ
> >           This is meant to be a general purpose policy.  It prioritises
> >           reads over writes.
> >
> > +config DM_CACHE_SMQ
> > +       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
> > +       depends on DM_CACHE
> > +       default y
> 
> A feature cannot be "EXPERIMENTAL", and be enabled by default.
> Please drop (at least) one of them.

Thanks for your concern, but: no.

If you look closer the entirety of DM cache is marked EXPERIMENTAL:

config DM_CACHE
       tristate "Cache target (EXPERIMENTAL)"
...
config DM_CACHE_MQ
       tristate "MQ Cache Policy (EXPERIMENTAL)"
...
config DM_CACHE_SMQ
       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
...
config DM_CACHE_CLEANER
       tristate "Cleaner Cache Policy (EXPERIMENTAL)"

Re: DM_CACHE_SMQ is experimental and enabled by default? (was: Re: dm cache: add stochastic-multi-queue (smq) policy)

[Geert Uytterhoeven]

Hi Mike,

On Fri, Jun 26, 2015 at 6:05 PM, Mike Snitzer <snitzer@redhat.com> wrote:
> On Fri, Jun 26 2015 at  3:47am -0400,
> Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
>> On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
>> <linux-kernel@vger.kernel.org> wrote:
>> > Gitweb:     http://git.kernel.org/linus/;a=commit;h=66a636356647a9be8885c2ce2948de126577698a
>> > Commit:     66a636356647a9be8885c2ce2948de126577698a
>> >
>> >     dm cache: add stochastic-multi-queue (smq) policy
>>
>> > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
>> > index edcf4ab..b597273 100644
>> > --- a/drivers/md/Kconfig
>> > +++ b/drivers/md/Kconfig
>> > @@ -304,6 +304,18 @@ config DM_CACHE_MQ
>> >           This is meant to be a general purpose policy.  It prioritises
>> >           reads over writes.
>> >
>> > +config DM_CACHE_SMQ
>> > +       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
>> > +       depends on DM_CACHE
>> > +       default y
>>
>> A feature cannot be "EXPERIMENTAL", and be enabled by default.
>> Please drop (at least) one of them.
>
> Thanks for your concern, but: no.
>
> If you look closer the entirety of DM cache is marked EXPERIMENTAL:
>
> config DM_CACHE
>        tristate "Cache target (EXPERIMENTAL)"

I stand corrected. Sorry for the fuss.

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