Lee Revell wrote:
On Thu, 2005-12-15 at 18:12 -0800, John Hawkes wrote:
From: "Lee Revell" <[email protected]>
There are 10 drivers that udelay(10000) or more and a TON that
udelay(1000). Turning those all into 1ms+ non preemptible sections will
be very bad.
What about 100usec non-preemptible sections?
That will disappear into the noise, in normal usage these happen all the
time. 500usec non preemptible regions are rare (~1 hour to show up) and
1ms very rare (24 hours). My tests show that 300 usec or so is a good
place to draw the line if you don't want it to show up in latency tests.
I may be misreading the original post, but the problem is described as
one where the TSC is not syncronised and a CPU switch takes place. Would
the correct solution be to somehow set CPU affinity temporarily in such
a way as to avoid disabling preempt at all?
The preempt doesn't seem to be the root problem, so it's unlikely to be
the best solution...
--
-bill davidsen ([email protected])
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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