On 14.03.22 22:13, Bezdeka, Florian via Xenomai wrote:
> On Mon, 2022-03-14 at 21:05 +0000, Bezdeka, Florian via Xenomai wrote:
>> Hi Richard,
>>
>> On Mon, 2022-03-14 at 21:38 +0100, Richard Weinberger via Xenomai
>> wrote:
>>> BITS_PER_LONG is too broad, the max number of usable bits is limited
>>> by nr_cpumask_bits.
>>
>> I agree, BITS_PER_LONG seems wrong. But couldn't it be too small as
>> well? It depends on NR_CPUS which might be > BITS_PER_LONG.
>
> Sorry that was unclear. I assume that the size of the cpumask depends
> somehow on NR_CPUS, which might be > BITS_PER_LONG. So BITS_PER_LONG
> might be too small AND might be too broad.
>
Good hint, I've adjusted this on merge.
Thanks,
Jan
>>
>> Regards,
>> Florian
>>
>>> Found while debugging a system with CONFIG_DEBUG_PER_CPU_MAPS enabled.
>>>
>>> Signed-off-by: Richard Weinberger <rich...@nod.at>
>>> ---
>>> kernel/cobalt/sched.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/kernel/cobalt/sched.c b/kernel/cobalt/sched.c
>>> index 88c4951ed814..aa65fd7f5d63 100644
>>> --- a/kernel/cobalt/sched.c
>>> +++ b/kernel/cobalt/sched.c
>>> @@ -1370,7 +1370,7 @@ static int affinity_vfile_show(struct
>>> xnvfile_regular_iterator *it,
>>> unsigned long val = 0;
>>> int cpu;
>>>
>>> - for (cpu = 0; cpu < BITS_PER_LONG; cpu++)
>>> + for (cpu = 0; cpu < nr_cpumask_bits; cpu++)
>>> if (cpumask_test_cpu(cpu, &cobalt_cpu_affinity))
>>> val |= (1UL << cpu);
>>>
>>> @@ -1395,7 +1395,7 @@ static ssize_t affinity_vfile_store(struct
>>> xnvfile_input *input)
>>> affinity = xnsched_realtime_cpus; /* Reset to default. */
>>> else {
>>> cpumask_clear(&affinity);
>>> - for (cpu = 0; cpu < BITS_PER_LONG; cpu++, val >>= 1) {
>>> + for (cpu = 0; cpu < nr_cpumask_bits; cpu++, val >>= 1) {
>>> if (val & 1) {
>>> /*
>>> * The new dynamic affinity must be a strict
>>
>
--
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