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

From: Mark Lord
Date: Fri Nov 30 2007 - 23:02:56 EST


Arjan van de Ven wrote:
On Fri, 30 Nov 2007 22:44:25 -0500
Mark Lord <lkml@xxxxxx> wrote:
all you need to do in your kernel module is call

add_latency_constraint("mark_wants_his_mouse", 5);
Okay, and how to change it back again? (thanks)


sorry I misremember it's called
set_acceptable_latency("mark", 5);

and to remove the constraint again you just do

remove_acceptable_latency("mark");

(and there's modify_ too to change existing)

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 ????

Having to hack source for any apps that one wants to use it on
sounds rather barbaric..

(sure I *can* still script it, with background tasksand wait and ..
but that's getting rather complex again).

Meanwhile.. I'll now cook up a module to try the set/remove_acceptable_latency thing.

Thanks
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