lkml.org 
[lkml]   [2023]   [Oct]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4] sched/core: Use zero length to reset cpumasks in sched_setaffinity()
On Wed, Oct 04, 2023 at 11:23:41AM +0200, Ingo Molnar wrote:

> > if (user_mask) {
> > - cpumask_copy(user_mask, in_mask);
> > + /*
> > + * All-set user cpumask resets affinity and drops the explicit
> > + * user mask.
> > + */
> > + cpumask_and(user_mask, in_mask, cpu_possible_mask);
> > + if (cpumask_equal(user_mask, cpu_possible_mask)) {
> > + kfree(user_mask);
> > + user_mask = NULL;
> > + }
>
> Question: is there any observable behavioral difference between current
> (old) all-set cpumask calls and the patched (new) one?

Very little I think -- the main difference is that we no longer carry
the ->user_cpus_ptr mask around, and that saves a little masking.


\
 
 \ /
  Last update: 2023-10-04 11:44    [W:0.082 / U:0.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site