Commit 6367b600 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Peter Zijlstra
Browse files

sched/isolation: Consolidate check for housekeeping minimum service 



There can be two subsequent calls to housekeeping_setup() due to
"nohz_full=" and "isolcpus=" that can mix up.  The two passes each have
their own way to deal with an empty housekeeping set of CPUs.
Consolidate this part and remove the awful "tmp" based naming.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJuri Lelli <juri.lelli@redhat.com>
Reviewed-by: default avatarPhil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-6-frederic@kernel.org
parent 04d4e665

kernel/sched/isolation.c

+17 −18
Original line number Diff line number Diff line
@@ -91,8 +91,7 @@ void __init housekeeping_init(void) 


static int __init housekeeping_setup(char *str, enum hk_flags flags)

{

	cpumask_var_t non_housekeeping_mask;

	cpumask_var_t tmp;

	cpumask_var_t non_housekeeping_mask, housekeeping_staging;



	alloc_bootmem_cpumask_var(&non_housekeeping_mask);

	if (cpulist_parse(str, non_housekeeping_mask) < 0) {
@@ -101,32 +100,32 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) 
		return 0;

	}



	alloc_bootmem_cpumask_var(&tmp);

	if (!housekeeping_flags) {

		alloc_bootmem_cpumask_var(&housekeeping_mask);

		cpumask_andnot(housekeeping_mask,

	alloc_bootmem_cpumask_var(&housekeeping_staging);

	cpumask_andnot(housekeeping_staging,

		       cpu_possible_mask, non_housekeeping_mask);



		cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);

		if (cpumask_empty(tmp)) {

	if (!cpumask_intersects(cpu_present_mask, housekeeping_staging)) {

		__cpumask_set_cpu(smp_processor_id(), housekeeping_staging);

		__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);

		if (!housekeeping_flags) {

			pr_warn("Housekeeping: must include one present CPU, "

				"using boot CPU:%d\n", smp_processor_id());

			__cpumask_set_cpu(smp_processor_id(), housekeeping_mask);

			__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);

		}

	}



	if (!housekeeping_flags) {

		alloc_bootmem_cpumask_var(&housekeeping_mask);

		cpumask_copy(housekeeping_mask, housekeeping_staging);

	} else {

		cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);

		if (cpumask_empty(tmp))

			__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);

		cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask);

		if (!cpumask_equal(tmp, housekeeping_mask)) {

		if (!cpumask_equal(housekeeping_staging, housekeeping_mask)) {

			pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");

			free_bootmem_cpumask_var(tmp);

			free_bootmem_cpumask_var(housekeeping_staging);

			free_bootmem_cpumask_var(non_housekeeping_mask);

			return 0;

		}

	}

	free_bootmem_cpumask_var(tmp);



	free_bootmem_cpumask_var(housekeeping_staging);



	if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {

		if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {