From fe4b04fa31a6dcf4358aa84cf81e5a7fd079469b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 Feb 2011 13:19:09 +0100 Subject: perf: Cure task_oncpu_function_call() races Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/sched.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index d747f948b34e..0b40ee3f6d7a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2578,13 +2578,6 @@ static inline void inc_syscw(struct task_struct *tsk) #define TASK_SIZE_OF(tsk) TASK_SIZE #endif -/* - * Call the function if the target task is executing on a CPU right now: - */ -extern void task_oncpu_function_call(struct task_struct *p, - void (*func) (void *info), void *info); - - #ifdef CONFIG_MM_OWNER extern void mm_update_next_owner(struct mm_struct *mm); extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p); -- cgit v1.2.3