11 Jul
2004
11 Jul
'04
9:21 p.m.
On Sun, 2004-07-11 at 12:30 +0200, Ingo Molnar wrote:
the reason is difference in overhead (codesize, speed)
and risks (driver
robustness). We do not want to enable preempt for Fedora yet because it
breaks just too much stuff and is too heavy. So we looked for a solution
that might work for a generic distro.
I think we should work toward being able to enable kernel preemption in
Fedora, then, instead of other tangential solutions.
And I disagree with the overhead argument. I have seen no specific
arguments that show a significant overhead. Heck, when people tried to
show that kernel preemption hurt throughput, we saw tests that showed
improved throughput (probably due to better utilization of I/O).
But stability is a subjective argument (and I agree we need more driver
love, at least for obscure drivers) wrt kernel preemption. So I would
say we should concentrate on working on the stability[1] so we could
just enable kernel preemption unconditionally and not designing new
solutions.
Best,
Robert Love
[1] What better way than enabling CONFIG_PREEMPT for Fedora? Enable it
for Fedora, and do not enable it for Red Hat Enterprise until you are
confidant. ;-)