Hi Yury, Replying back in plaintext, as you sent an HTML message. On Sun, 2022-08-21 at 09:18 -0400, Yury Norov wrote: > > > On Sun, Aug 21, 2022, 09:08 Sander Vanheule <sander@xxxxxxxxxxxxx> wrote: > > Hi Yury, > > > > On Sat, 2022-08-20 at 14:35 -0700, Yury Norov wrote: > > > On Sat, Aug 20, 2022 at 05:03:09PM +0200, Sander Vanheule wrote: > > > > When the number of CPUs that can possibly be brought online is known at > > > > boot time, e.g. when HOTPLUG is disabled, nr_cpu_ids may be smaller than > > > > NR_CPUS. In that case, cpu_possible_mask would not be completely filled, > > > > and cpumask_full(cpu_possible_mask) can return false for valid system > > > > configurations. > > > > > > It doesn't mean we can just give up. You can check validity of possible > > > cpumask like this: > > > KUNIT_EXPECT_EQ(test, nr_cpu_ids, cpumask_first_zero(&mask_all)) > > > KUNIT_EXPECT_EQ(test, NR_CPUS, cpumask_first(&mask_all)) > > > > Did you mean cpu_possible_mask, or mask_all? > > cpu_possble_as of curse. > > > For cpu_possible_mask, these tests are in test_cpumask_first(), albeit under > > a > > slightly different form. Together with the tests in test_cpumask_weight() > > and > > test_cpumask_last(), cpu_possible_mask is already one of the more > > constrained > > masks. > > > > > > For mask_all, the mask is filled up with nr_cpumask_bits <= NR_CPUS. I could > > add > > cpumask_first(), cpumask_first_zero(), and cpumask_last() tests though. > > > > More tests could be also added for cpu_all_mask, since this does have all > > NR_CPUS bits set, but I think that belongs in a separate patch. > > > > I think the extra mask_all and cpu_all_mask test are out of scope for this > > patch, but they could be added in another patch (for 6.1). > > If you think that possible mask is tested by other parts, then can you notice > that in comments? Sure, I'll update the commit message to note the other constraints on cpu_possible_mask. Best, Sander
