Re: + restore-missing-sysfs-max_cstate-attr.patch added to -mm tree

Mark Lord
2007-12-01T04:31:15Z

Mark Lord wrote:
> Arjan van de Ven wrote:
>> On Fri, 30 Nov 2007 22:44:25 -0500
>> Mark Lord <lkml@rtr.ca> wrote:
>>>> all you need to do in your kernel module is call
...
>> set_acceptable_latency("mark", 5);
>>
>> and to remove the constraint again you just do
>>
>> remove_acceptable_latency("mark");
..
>>> Then why not have a sysfs entry for scripts to write tsoro
>>> to trigger the exact same end result? :)
>>
>> that's what is in current -mm pretty much
>> well not sysfs, but it goes via a file descriptor
>> (so that if the process that sets the contraint dies, the latency
>> requirement can be given up automatically)
> ...
>
> But doesn't that approach also make it nearly impossible to script ????
...

Okay, I have a working trivial kernel module that I can load/unload
to tweak this. But a simple sysfs attribute would be *so much* better
as a permanent kernel feature.

Binary interfaces (fd) are fine for some uses, but not nice for scripts.

Cheers