Re: [patch] sched: fix scheduling latencies for !PREEMPT kernels

[Lee Revell]

On Tue, 2004-09-14 at 21:39, William Lee Irwin III wrote:
> > With Ingo's patches the worst case latency on the same machine as my XP
> > example is about 150 usecs.  So, it seems to me that Ingo's patches can
> > achieve results as good or better than OSX even without the one or two
> > "dangerous" changes, like the removal of lock_kernel around
> > do_tty_write.
> 
> The code we're most worried is buggy, not just nonperformant.
> 

Understood.  The only dangerous change I know of in the VP patches is
the one Alan took issue with, the aforementioned removal of lock_kernel
in the tty code.  IIRC this only produced a latency of about 300 usecs,
and only when switching VT's from a console to X and back.  My point was
that it's quite possible that we can get OSX-like results without the
more dangerous changes.

Ingo, if you want to send me a patch set without the more controversial
changes, I can compare the performance.  A diff against the latest VP
patch would be OK.

Lee



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