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sched/isolation: Require a present CPU in housekeeping mask

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During housekeeping mask setup, currently a possible CPU is required.
That does not guarantee the CPU would be available at boot time, so
check to ensure that at least one present CPU is in the mask.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lkml.kernel.org/r/20190411033448.20842-5-npiggin@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Nicholas Piggin 2019-04-11 13:34:47 +10:00 committed by Ingo Molnar
parent 9ca12ac04b
commit 9219565aa8
1 changed files with 14 additions and 6 deletions
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20
kernel/sched/isolation.c
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@ -65,6 +65,7 @@ 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;
int err;
alloc_bootmem_cpumask_var(&non_housekeeping_mask);
@ -75,16 +76,23 @@ 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,
cpu_possible_mask, non_housekeeping_mask);
if (cpumask_empty(housekeeping_mask))
__cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
} else {
cpumask_var_t tmp;
alloc_bootmem_cpumask_var(&tmp);
cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);
if (cpumask_empty(tmp)) {
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);
}
} 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)) {
pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");
@ -92,8 +100,8 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags)
free_bootmem_cpumask_var(non_housekeeping_mask);
return 0;
}
free_bootmem_cpumask_var(tmp);
}
free_bootmem_cpumask_var(tmp);
if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {
if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {