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On 3/19/26 9:06 AM, Yury Norov wrote: > Switch the function to using modern cpumask API and drop most of the > housekeeping code. > > Notice, if first >= nr_cpu_ids, for_each_cpu_wrap() iterator behaves just > like for_each_cpu(), i.e. begins from 0. So even if WARN_ON() is triggered, > no special handling is needed. > > Signed-off-by: Yury Norov > --- > arch/powerpc/sysdev/xive/common.c | 31 ++++++------------------------- > 1 file changed, 6 insertions(+), 25 deletions(-) > > diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c > index e91ec9036ad8..4e05f678e171 100644 > --- a/arch/powerpc/sysdev/xive/common.c > +++ b/arch/powerpc/sysdev/xive/common.c > @@ -548,40 +548,21 @@ static void xive_dec_target_count(int cpu) > static int xive_find_target_in_mask(const struct cpumask *mask, > unsigned int fuzz) > { > - int cpu, first, num, i; > + int cpu, first; > > /* Pick up a starting point CPU in the mask based on fuzz */ > - num = cpumask_weight(mask); > - first = fuzz % num; > - > - /* Locate it */ > - cpu = cpumask_first(mask); > - for (i = 0; i < first && cpu < nr_cpu_ids; i++) > - cpu = cpumask_next(cpu, mask); > - > - /* Sanity check */ > - if (WARN_ON(cpu >= nr_cpu_ids)) > - cpu = cpumask_first(cpu_online_mask); > - > - /* Remember first one to handle wrap-around */ > - first = cpu; > + fuzz %= cpumask_weight(mask); > + first = cpumask_nth(fuzz, mask); > + WARN_ON(first >= nr_cpu_ids); > > /* > * Now go through the entire mask until we find a valid > * target. > */ > - do { > - /* > - * We re-check online as the fallback case passes us > - * an untested affinity mask > - */ > + for_each_cpu_wrap(cpu, mask, first) { > if (cpu_online(cpu) && xive_try_pick_target(cpu)) > return cpu; > - cpu = cpumask_next(cpu, mask); > - /* Wrap around */ > - if (cpu >= nr_cpu_ids) > - cpu = cpumask_first(mask); > - } while (cpu != first); > + } > > return -1; > } Only concern i have, (which could potentially leads to while(1) loop today if it), is if mask is empty. atleast for_each_cpu_wrap will not be a while(1) loop. So, IMO this is better than what we have today. nit: maybe a good to add a WARN_ON(cpu >= nr_cpu_ids) in the end. Reviewed-by: Shrikanth Hegde