| Message ID | 6dfd4d3a4d77f97f13ab3f22bc53c96c38ba908e.1661007339.git.sander@svanheule.net (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cpumask: KUnit test suite fixes and improvements | expand |
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)) > Fixes: c41e8866c28c ("lib/test: introduce cpumask KUnit test suite") > Link: https://lore.kernel.org/lkml/346cb279-8e75-24b0-7d12-9803f2b41c73@riseup.net/ > Reported-by: Maíra Canal <mairacanal@riseup.net> > Signed-off-by: Sander Vanheule <sander@svanheule.net> > Tested-by: Maíra Canal <mairacanal@riseup.net> > Reviewed-by: David Gow <davidgow@google.com> > --- > Changes in v2: > Rewrite commit message to explain why this test is wrong > > lib/test_cpumask.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/lib/test_cpumask.c b/lib/test_cpumask.c > index a31a1622f1f6..4ebf9f5805f3 100644 > --- a/lib/test_cpumask.c > +++ b/lib/test_cpumask.c > @@ -54,7 +54,6 @@ static cpumask_t mask_all; > static void test_cpumask_weight(struct kunit *test) > { > KUNIT_EXPECT_TRUE(test, cpumask_empty(&mask_empty)); > - KUNIT_EXPECT_TRUE(test, cpumask_full(cpu_possible_mask)); > KUNIT_EXPECT_TRUE(test, cpumask_full(&mask_all)); > > KUNIT_EXPECT_EQ(test, 0, cpumask_weight(&mask_empty)); > -- > 2.37.2
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? 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). Best, Sander > > > Fixes: c41e8866c28c ("lib/test: introduce cpumask KUnit test suite") > > Link: > > https://lore.kernel.org/lkml/346cb279-8e75-24b0-7d12-9803f2b41c73@riseup.net/ > > Reported-by: Maíra Canal <mairacanal@riseup.net> > > Signed-off-by: Sander Vanheule <sander@svanheule.net> > > Tested-by: Maíra Canal <mairacanal@riseup.net> > > Reviewed-by: David Gow <davidgow@google.com> > > --- > > Changes in v2: > > Rewrite commit message to explain why this test is wrong > > > > lib/test_cpumask.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/lib/test_cpumask.c b/lib/test_cpumask.c > > index a31a1622f1f6..4ebf9f5805f3 100644 > > --- a/lib/test_cpumask.c > > +++ b/lib/test_cpumask.c > > @@ -54,7 +54,6 @@ static cpumask_t mask_all; > > static void test_cpumask_weight(struct kunit *test) > > { > > KUNIT_EXPECT_TRUE(test, cpumask_empty(&mask_empty)); > > - KUNIT_EXPECT_TRUE(test, cpumask_full(cpu_possible_mask)); > > KUNIT_EXPECT_TRUE(test, cpumask_full(&mask_all)); > > > > KUNIT_EXPECT_EQ(test, 0, cpumask_weight(&mask_empty)); > > -- > > 2.37.2
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@svanheule.net> 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
diff --git a/lib/test_cpumask.c b/lib/test_cpumask.c index a31a1622f1f6..4ebf9f5805f3 100644 --- a/lib/test_cpumask.c +++ b/lib/test_cpumask.c @@ -54,7 +54,6 @@ static cpumask_t mask_all; static void test_cpumask_weight(struct kunit *test) { KUNIT_EXPECT_TRUE(test, cpumask_empty(&mask_empty)); - KUNIT_EXPECT_TRUE(test, cpumask_full(cpu_possible_mask)); KUNIT_EXPECT_TRUE(test, cpumask_full(&mask_all)); KUNIT_EXPECT_EQ(test, 0, cpumask_weight(&mask_empty));
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. Fixes: c41e8866c28c ("lib/test: introduce cpumask KUnit test suite") Link: https://lore.kernel.org/lkml/346cb279-8e75-24b0-7d12-9803f2b41c73@riseup.net/ Reported-by: Maíra Canal <mairacanal@riseup.net> Signed-off-by: Sander Vanheule <sander@svanheule.net> Tested-by: Maíra Canal <mairacanal@riseup.net> Reviewed-by: David Gow <davidgow@google.com> --- Changes in v2: Rewrite commit message to explain why this test is wrong lib/test_cpumask.c | 1 - 1 file changed, 1 deletion(-)