From d5e1586617be7093ea3419e3fa9387ed833cdbb1 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 2 Jun 2023 10:42:53 +0200 Subject: sched: Unconditionally use full-fat wait_task_inactive() While modifying wait_task_inactive() for PREEMPT_RT; the build robot noted that UP got broken. This led to audit and consideration of the UP implementation of wait_task_inactive(). It looks like the UP implementation is also broken for PREEMPT; consider task_current_syscall() getting preempted between the two calls to wait_task_inactive(). Therefore move the wait_task_inactive() implementation out of CONFIG_SMP and unconditionally use it. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230602103731.GA630648%40hirez.programming.kicks-ass.net --- include/linux/sched.h | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index eed5d65b8d1f..1292d38d66cc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2006,15 +2006,12 @@ static __always_inline void scheduler_ipi(void) */ preempt_fold_need_resched(); } -extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); #else static inline void scheduler_ipi(void) { } -static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) -{ - return 1; -} #endif +extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); + /* * Set thread flags in other task's structures. * See asm/thread_info.h for TIF_xxxx flags available: -- cgit v1.2.3