From 051a1d1afa47206e23ae03f781c6795ce870e3d5 Mon Sep 17 00:00:00 2001 From: Dmitry Adamushko Date: Tue, 18 Dec 2007 15:21:13 +0100 Subject: [PATCH] sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko Signed-off-by: Ingo Molnar Tested-by: Dhaval Giani Tested-by: KAMEZAWA Hiroyuki --- kernel/sched.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index c6e551de79..5ae0d4296e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -508,10 +508,15 @@ EXPORT_SYMBOL_GPL(cpu_clock); # define finish_arch_switch(prev) do { } while (0) #endif +static inline int task_current(struct rq *rq, struct task_struct *p) +{ + return rq->curr == p; +} + #ifndef __ARCH_WANT_UNLOCKED_CTXSW static inline int task_running(struct rq *rq, struct task_struct *p) { - return rq->curr == p; + return task_current(rq, p); } static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) @@ -540,7 +545,7 @@ static inline int task_running(struct rq *rq, struct task_struct *p) #ifdef CONFIG_SMP return p->oncpu; #else - return rq->curr == p; + return task_current(rq, p); #endif } @@ -3334,7 +3339,7 @@ unsigned long long task_sched_runtime(struct task_struct *p) rq = task_rq_lock(p, &flags); ns = p->se.sum_exec_runtime; - if (rq->curr == p) { + if (task_current(rq, p)) { update_rq_clock(rq); delta_exec = rq->clock - p->se.exec_start; if ((s64)delta_exec > 0) @@ -4021,7 +4026,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio) oldprio = p->prio; on_rq = p->se.on_rq; - running = task_running(rq, p); + running = task_current(rq, p); if (on_rq) { dequeue_task(rq, p, 0); if (running) @@ -4332,7 +4337,7 @@ recheck: } update_rq_clock(rq); on_rq = p->se.on_rq; - running = task_running(rq, p); + running = task_current(rq, p); if (on_rq) { deactivate_task(rq, p, 0); if (running) @@ -7101,7 +7106,7 @@ void sched_move_task(struct task_struct *tsk) update_rq_clock(rq); - running = task_running(rq, tsk); + running = task_current(rq, tsk); on_rq = tsk->se.on_rq; if (on_rq) { -- 2.20.1