Messages in this thread | | | Date | Mon, 28 Jan 2008 10:37:14 -0800 | From | Max Krasnyanskiy <> | Subject | Re: [CPUISOL] CPU isolation extensions |
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Paul Jackson wrote: > Thanks for the CC, Peter. > > Ingo - see question at end of message. > > Max wrote: >> We've had scheduler support for CPU isolation ever since O(1) scheduler went it. >> I'd like to extend it further to avoid kernel activity on those CPUs as much as possible. > > I recently added the per-cpuset flag 'sched_load_balance' for some > other realtime folks, so that they can disable the kernel scheduler > load balancing on isolated CPUs. It essentially allows for dynamic > control of which CPUs are isolated by the scheduler, using the cpuset > hierarchy, rather than enhancing the 'isolated_cpus' mask. That > 'isolated_cpus' mask remained a minimal kernel boottime parameter. > I believe this went to Linus's tree about Oct 2007. > > It looks like you have three additional tweaks for realtime in this > patch set, with your patches: > > [PATCH] [CPUISOL] Do not route IRQs to the CPUs isolated at boot > [PATCH] [CPUISOL] Support for workqueue isolation > [PATCH] [CPUISOL] Isolated CPUs should be ignored by the "stop machine" > > It would be interesting to see a patchset with the above three realtime > tweaks, layered on this new cpuset 'sched_load_balance' apparatus, rather > than layered on changes to make 'isolated_cpus' more dynamic. Some of us > run realtime and cpuset-intensive loads on the same system, so like to > have those two capabilities co-operate with each other. I'll definitely take a look. So far it seems that extending cpu_isolated_map is more natural way of propagating this notion to the rest of the kernel. Since it's very similar to the cpu_online_map concept and it's easy to integrated with the code that already uses it. Anyway. I'll take a look at the cpuset flag that you mentioned and report back.
Thanx Max
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