| Message ID | 20210811201354.1976839-5-valentin.schneider@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/4] rcutorture: Don't disable softirqs with preemption disabled when PREEMPT_RT | expand |
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index f09bf5c02891..8c0de3234b20 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -995,7 +995,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, */ static inline bool arch_faults_on_old_pte(void) { - WARN_ON(preemptible()); + WARN_ON(migratable()); return !cpu_has_hw_af(); }
arch_faults_on_old_pte() relies on the calling context being non-preemptible. CONFIG_PREEMPT_RT turns the PTE lock into a sleepable spinlock, which doesn't disable preemption once acquired, triggering the warning in arch_faults_on_old_pte(). It does however disable migration, ensuring the task remains on the same CPU during the entirety of the critical section, making the read of cpu_has_hw_af() safe and stable. Make arch_faults_on_old_pte() check migratable() instead of preemptible(). Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- arch/arm64/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)