[Re: [PATCH 1/2] bitmap_parse: support 'all' semantics] On 21/04/2021 (Wed 11:19) Steven Rostedt wrote: > On Tue, 20 Apr 2021 20:13:25 -0700 > Yury Norov <yury.norov@xxxxxxxxx> wrote: > > > @@ -76,6 +76,11 @@ to change, such as less cores in the CPU list, then N and any ranges using N > > will also change. Use the same on a small 4 core system, and "16-N" becomes > > "16-3" and now the same boot input will be flagged as invalid (start > end). > > > > +The special case-tolerant group name "all" has a meaning of selecting all CPUs, > > +such that "isolcpus=all" is the equivalent of "isolcpus=0-N". > > I'm OK with the concept of this patch set, but really? That is a horrible > example. One should NEVER set isolcpus to all! It wouldn't have parsed anyways. The "isolcpus=" would just think "all" was an unsupported flag and discard it before it ever got to cpu/bitmap processing. See 3662daf02350 "sched/isolation: Allow "isolcpus=" to skip unknown sub-parameters". The use case example Paul chose (not me; the smart Paul) is better. Paul. -- > > -- Steve > > > > + > > +The semantics of "N" and "all" is supported on a level of bitmaps and holds for > > +all users of bitmap_parse(). > >
