From 26baa1f1c4bdc34b8d698c1900b407d863ad0e69 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 4 Oct 2024 14:47:02 +0200 Subject: sched: Add TIF_NEED_RESCHED_LAZY infrastructure Add the basic infrastructure to split the TIF_NEED_RESCHED bit in two. Either bit will cause a resched on return-to-user, but only TIF_NEED_RESCHED will drive IRQ preemption. No behavioural change intended. Suggested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Sebastian Andrzej Siewior Link: https://lkml.kernel.org/r/20241007075055.219540785@infradead.org --- include/linux/thread_info.h | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) (limited to 'include/linux/thread_info.h') diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 9ea0b28068f4..cf2446c9c30d 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -59,6 +59,14 @@ enum syscall_work_bit { #include +#ifndef TIF_NEED_RESCHED_LAZY +#ifdef CONFIG_ARCH_HAS_PREEMPT_LAZY +#error Inconsistent PREEMPT_LAZY +#endif +#define TIF_NEED_RESCHED_LAZY TIF_NEED_RESCHED +#define _TIF_NEED_RESCHED_LAZY _TIF_NEED_RESCHED +#endif + #ifdef __KERNEL__ #ifndef arch_set_restart_data @@ -179,22 +187,27 @@ static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti #ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H -static __always_inline bool tif_need_resched(void) +static __always_inline bool tif_test_bit(int bit) { - return arch_test_bit(TIF_NEED_RESCHED, + return arch_test_bit(bit, (unsigned long *)(¤t_thread_info()->flags)); } #else -static __always_inline bool tif_need_resched(void) +static __always_inline bool tif_test_bit(int bit) { - return test_bit(TIF_NEED_RESCHED, + return test_bit(bit, (unsigned long *)(¤t_thread_info()->flags)); } #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */ +static __always_inline bool tif_need_resched(void) +{ + return tif_test_bit(TIF_NEED_RESCHED); +} + #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES static inline int arch_within_stack_frames(const void * const stack, const void * const stackend, -- cgit v1.2.3