2015-06-26 07:47:55

by Geert Uytterhoeven

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

On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
<[email protected]> wrote:
> Gitweb: http://git.kernel.org/linus/;a=commit;h=66a636356647a9be8885c2ce2948de126577698a
> Commit: 66a636356647a9be8885c2ce2948de126577698a
> Parent: 40775257b97e27305cf5c2425be7acaa6edee4ea
> Refname: refs/heads/master
> Author: Joe Thornber <[email protected]>
> AuthorDate: Fri May 15 15:33:34 2015 +0100
> Committer: Mike Snitzer <[email protected]>
> 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 -- [email protected]

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

2015-06-26 16:05:59

by Mike Snitzer

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

On Fri, Jun 26 2015 at 3:47am -0400,
Geert Uytterhoeven <[email protected]> wrote:

> On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
> <[email protected]> wrote:
> > Gitweb: http://git.kernel.org/linus/;a=commit;h=66a636356647a9be8885c2ce2948de126577698a
> > Commit: 66a636356647a9be8885c2ce2948de126577698a
> > Parent: 40775257b97e27305cf5c2425be7acaa6edee4ea
> > Refname: refs/heads/master
> > Author: Joe Thornber <[email protected]>
> > AuthorDate: Fri May 15 15:33:34 2015 +0100
> > Committer: Mike Snitzer <[email protected]>
> > 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)"

2015-07-01 07:25:59

by Geert Uytterhoeven

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

Hi Mike,

On Fri, Jun 26, 2015 at 6:05 PM, Mike Snitzer <[email protected]> wrote:
> On Fri, Jun 26 2015 at 3:47am -0400,
> Geert Uytterhoeven <[email protected]> wrote:
>
>> On Fri, Jun 26, 2015 at 2:13 AM, Linux Kernel Mailing List
>> <[email protected]> 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 -- [email protected]

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