Messages in this thread | | | Date | Fri, 27 Oct 2017 15:58:31 +0200 | From | Peter Zijlstra <> | Subject | Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags |
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On Fri, Oct 27, 2017 at 05:06:25AM -0700, tip-bot for Frederic Weisbecker wrote: > + isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance. > + Format: [flag-list,]<cpu-list> > + > + Specify one or more CPUs to isolate from disturbances > + specified in the flag list (default: domain): > + > + nohz > + Disable the tick when a single task runs. > + domain > + Isolate from the general SMP balancing and scheduling > + algorithms. This option is the preferred way to isolate > + CPUs from tasks.
I _strongly_ object to this statement, isolcpus is _not_ the preferred way, cpusets are.
And yes, while cpusets suffers some problems, we _should_ really fix those and not promote this piece of shit isolcpus crap.
> The alternative -- manually setting the > + CPU mask of all tasks in the system, can cause problems > + and suboptimal load balancer performance. You can move a > + process onto or off an "isolated" CPU via the CPU > + affinity syscalls or cpuset. <cpu number> begins at 0 > + and the maximum value is "number of CPUs in system - 1". > + > + The format of <cpu-list> is described above. > +
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