Re: [PATCH V15 00/11] x86: Intel Cache Allocation Technology Support

From: Thomas Gleixner
Date: Wed Nov 04 2015 - 10:51:31 EST


On Wed, 4 Nov 2015, Luiz Capitulino wrote:
> On Wed, 4 Nov 2015 16:28:04 +0100 (CET)
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> > On Wed, 4 Nov 2015, Luiz Capitulino wrote:
> > > On Wed, 4 Nov 2015 15:57:41 +0100 (CET)
> > > Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > >
> > > > On Wed, 4 Nov 2015, Luiz Capitulino wrote:
> > > >
> > > > > On Thu, 1 Oct 2015 23:09:34 -0700
> > > > > Fenghua Yu <fenghua.yu@xxxxxxxxx> wrote:
> > > > >
> > > > > > This series has some preparatory patches and Intel cache allocation
> > > > > > support.
> > > > >
> > > > > Ping? What's the status of this series?
> > > >
> > > > We still need to agree on the user space interface which is the
> > > > hardest part of it....
> > >
> > > My understanding is that two interfaces have been proposed: the cgroups
> > > one and an API based on syscalls or ioctls.
> > >
> > > Are those proposals mutual exclusive? What about having the cgroups one
> > > merged IFF it's useful, and having the syscall API later if really
> > > needed?
> > >
> > > I don't want to make the wrong decision, but the cgroups interface is
> > > here. Holding it while we discuss a perfect interface that doesn't
> > > even exist will just do a bad service for users.
> >
> > Well, no. We do not just introduce a random user space ABI simply
> > because we have to support it forever.
>
> I don't think it's random, it's in discussion for a long time and
> Peter seems to be in favor of it.

It does not matter whether it's in discussion for a long time. We have
requests for functionality which cannot be covered with that
interface.

> But I'm all for progress here whatever route we take. In that regard,
> what's your opinion on the best way to move forward?

Talk to the people in your very company, who are having a different
opinion and requests for stuff which cannot be handled by the current
proposed interface. You had yourself a list of things you want to see
handled.

So feel free to come up with patches which implement that instead of
telling us that your company needs it badly for some reason.

Thanks,

tglx
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