Re: [patch] Real-Time Preemption, -RT-2.6.13-rc4-V0.7.52-01

Steven Rostedt
2005-08-03T00:00:49Z

On Tue, 2005-08-02 at 16:38 -0700, Daniel Walker wrote:
> Couldn't you just do some math off current->timestamp to see how long
> the task has been running? This per arch stuff seems a bit invasive..

The thing is, I'm tracking how long the task is running in the kernel
without doing a schedule. That's actually easy, but I don't want to
count when the task is in userspace. The per-arch is only updating so
that we don't count user space, otherwise the count could be in the
task_struct. If there is an arch-independent way to tell if a task is
running in user-space or kernel when an interrupt goes off then I would
use it. The per arch is actually easy, and I would write it, but I
don't have the hardware now to test it. I could at least do PPC and
MIPS since I'm quite familiar with both, but I don't currently have a
cross compiler to compile it.

I understand your point, I would really prefer an arch independent
solution, but the timestamp from current just wont cut it. Have another
idea, I'm all open for it.

So far, what I submitted works with no know side-effects except that it
is a per-arch patch, which does suck.

-- Steve