Re: Moving from /proc/acpi to /sys

Alex Williamson
2004-06-18T20:56:38Z

On Fri, 2004-06-18 at 13:56, Keshavamurthy Anil S wrote:
> On Fri, Jun 18, 2004 at 08:43:36PM +0100, Matthew Wilcox wrote:
> > On Fri, Jun 18, 2004 at 10:41:17AM -0700, Keshavamurthy, Anil S wrote:
> > > Hi,
> > > I am curious to know whether anybody is working or even planning
> > > to port
> > > all the acpi related entries from /proc/acpi to the corresponding
> > > /sysfs entries.
> >
> > Alex Williamson had a patch to fill in the methods under /sys ...
> Hi Alex,
> I am working on to support ACPI based cpu hotplug where in I am
> in the process of modifying ACPI processor driver. Since with the hotplug
> support I see some of the entries for the processor under /sys/device/system/cpu
> and some under /proc/acpi/processor. I felt it would be good if we have everything
> under the /sys fs directory. I would be glad to contribute to your patch for the
> processor driver changes. Can you please let me know where you are on this patch and
> and what are the things you are considering to move and lastly what is the timeline
> you are looking to push this patch.
>
> thanks,
> Anil
>

Anil,

The patch I'm working on isn't meant as a replacement to the current
/proc/acpi entries. It's meant more as a means for userspace to
directly interact w/ ACPI namespace. Here's a link to the last thread
about the patch:

http://marc.theaimsgroup.com/?l=acpi4linux&m=108154985013230&w=2

It fills in files in /sys/firmware/acpi/namespace/ACPI such that methods
and objects can be evaluated using a simple read/write interface. In
some cases, a set of libraries and daemon could achieve the same results
as the current /proc/acpi drivers, but I don't think this is necessarily
the way to go in all cases.

Are there ACPI specific features under /proc/acpi/processor that you
need for cpu hotplug? I would assume that you'd want to abstract the
implementation and have generic calls under /sys/device/system/cpu.
Anyway, have a look at what my patch does and let me know if it's useful
to you. I don't think it's the port of /proc/acpi that you're thinking
it might be, but I'm happy to take suggestions. I plan to pick it up
again soon, but pushing the patch really depends on getting some
interest in it. Thanks,

Alex