Messages in this thread | | | Subject | Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory barrier | From | Peter Zijlstra <> | Date | Thu, 07 Jan 2010 09:44:15 +0100 |
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On Wed, 2010-01-06 at 22:35 -0800, Josh Triplett wrote: > > The number of threads doesn't matter nearly as much as the number of > threads typically running at a time compared to the number of > processors. Of course, we can't measure that as easily, but I don't > know that your proposed heuristic would approximate it well.
Quite agreed, and not disturbing RT tasks is even more important.
A simple:
for_each_cpu(cpu, current->mm->cpu_vm_mask) { if (cpu_curr(cpu)->mm == current->mm) smp_call_function_single(cpu, func, NULL, 1); }
seems far preferable over anything else, if you really want you can use a cpumask to copy cpu_vm_mask in and unset bits and use the mask with smp_call_function_any(), but that includes having to allocate the cpumask, which might or might not be too expensive for Mathieu.
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