Messages in this thread | | | Date | Thu, 7 Jan 2021 15:18:47 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH RFC cpumask 4/5] cpumask: Add "last" alias for cpu list specifications |
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On Wed, Jan 06, 2021 at 01:16:50PM -0800, Yury Norov wrote: > On Wed, Jan 6, 2021 at 1:50 AM Peter Zijlstra <peterz@infradead.org> wrote:
> > Aside from the comments Yury made, on how all this is better in > > bitmap_parselist(), how about doing s/last/N/ here? For me something > > like: "4-N" reads much saner than "4-last". > > > > Also, it might make sense to teach all this about core/node topology, > > but that's going to be messy. Imagine something like "Core1-CoreN" or > > "Nore1-NodeN" to mean the mask all/{Core,Node}0. > > If you just want to teach bitmap_parselist() to "s/Core0/0-4", I think > it's doable if we add a hook to a proper subsystem in bitmap_parselist(). > > > And that is another feature that seems to be missing from parselist, > > all/except. > > We already support groups in a range. I think it partially covers the > proposed all/except. > > Can you share examples on what you miss?
The obvious one is the "all/Core0" example above, which would be equivalent to "Core1-CoreN".
Another case that I don't think we can do today is something like, give me SMT0 of each core.
I don't really see the use of the ranges thing, CPU enumeration just isn't sane like that. Also, I should really add that randomization pass to the CPU enumeration :-)
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