Re: [patch] scheduler bits from 2.5.23-dj1

Dave Jones
2002-06-19T23:47:30Z

On Thu, Jun 20, 2002 at 01:35:35AM +0200, Ingo Molnar wrote:

Hi Ingo,

> the scheduler optimisation in 2.5.23-dj1, from James Bottomley, look fine
> to me. I did some modifications:

Thanks for taking time out to look them over..
The bulk of the UP optimisation was by Mikael Petterson, James just
fixed up something I goofed in an earlier patchset.

> - there is no need for the #if CONFIG_SMP, gcc is good at optimizing away
> a branch if it has a (0 != 0) condition on UP :-)

*nod*, I had intended to clean this up, but there's only so many hours
in a day.. 8-)

> another change in 2.5.23-dj1 is the initialization of the pidhash in
> sched_init(). It does not belong there - please create a new init function
> within fork.c if needed. The pidhash init used to be in sched_init(), but
> this doesnt make it right.

Agreed.

> And i'm not quite sure whether it's needed to expose the pidhash to the
> rest of the kernel - it would be much simpler to have it in kernel/fork.c
> locally, and find_task_by_pid() would be a function instead of an inline.
> (it has a ~49 bytes footprint on x86, it's rather heavy i think.)

I'll take a look at this tomorrow, unless William "no sleep `til 2.6" Irwin
beats me to it 8-) (he did this part of the patch iirc).

> my current scheduler patchset (against 2.5.23, tested) is attached.

Thanks again.

Dave.

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