[patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.21
From: Ingo Molnar
Date: Mon Nov 08 2004 - 12:07:12 EST
i have released the -V0.7.21 Real-Time Preemption patch, which can be
downloaded from the usual place:
this release includes fixes and debugging-improvements.
Changes since -V0.7.20:
- reverted the modlist_lock change - it caused more problems than it
- implemented irqs-off critical section timing/tracing, inspired by the
positive results Thomas Gleixner got with a different kind of cli/sti
tracer. To activate it, enable CONFIG_CRITICAL_TIMING and
CONFIG_CRITICAL_IRQSOFF_TIMING and cli/sti latencies will be reported
'integrated' into the preempt on/off latencies.
- sped up tracing in a number of ways. Performance of the tracer slowly
eroded in the past week or two, it needed alignment and size fixes ,
inlining/branch-prediction updates and i got rid of unnecessary code.
The max latency is now traced in cycles - this got rid of an
expensive 64-bit division in the fastpath. (the /proc/sys tunables
are still in usecs so userspace should not notice anything.) It's
still not cheap but roughly 5 times faster than -V0.7.20's tracer, on
a fast desktop box.
- renamed CONFIG_PREEMPT_REALTIME to CONFIG_PREEMPT_RT - it's shorter.
- renamed CONFIG_PREEMPT_TIMING to CONFIG_CRITICAL_TIMING and
introduced CONFIG_CRITICAL_IRQSOFF_TIMING to enable cli/sti timing.
to create a -V0.7.21 tree from scratch, the patching order is:
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