Messages in this thread Patch in this message | | | Date | Sat, 26 Aug 2006 23:18:17 +0400 | From | Oleg Nesterov <> | Subject | [PATCH 3/3] introduce TASK_DEAD state |
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I am not sure about this patch, I am asking Ingo to take a decision.
task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should live only in ->exit_state as documented in sched.h.
Note that this state is not visible to user-space, get_task_state() masks off unsuitable states.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 2.6.18-rc4/include/linux/sched.h~3_rename 2006-08-26 21:28:54.000000000 +0400 +++ 2.6.18-rc4/include/linux/sched.h 2006-08-26 23:03:44.000000000 +0400 @@ -148,6 +148,7 @@ extern unsigned long weighted_cpuload(co #define EXIT_DEAD 32 /* in tsk->state again */ #define TASK_NONINTERACTIVE 64 +#define TASK_DEAD 128 #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) --- 2.6.18-rc4/kernel/exit.c~3_rename 2006-08-26 21:46:45.000000000 +0400 +++ 2.6.18-rc4/kernel/exit.c 2006-08-26 22:31:50.000000000 +0400 @@ -955,7 +955,7 @@ fastcall NORET_TYPE void do_exit(long co preempt_disable(); /* causes final put_task_struct in finish_task_switch(). */ - tsk->state = EXIT_DEAD; + tsk->state = TASK_DEAD; schedule(); BUG(); --- 2.6.18-rc4/kernel/sched.c~3_rename 2006-08-26 21:56:46.000000000 +0400 +++ 2.6.18-rc4/kernel/sched.c 2006-08-26 22:37:48.000000000 +0400 @@ -1751,10 +1751,10 @@ static inline void finish_task_switch(st /* * A task struct has one reference for the use as "current". - * If a task dies, then it sets EXIT_DEAD in tsk->state and calls + * If a task dies, then it sets TASK_DEAD in tsk->state and calls * schedule one last time. The schedule call will never return, and * the scheduled task must drop that reference. - * The test for EXIT_DEAD must occur while the runqueue locks are + * The test for TASK_DEAD must occur while the runqueue locks are * still held, otherwise prev could be scheduled on another cpu, die * there before we look at prev->state, and then the reference would * be dropped twice. @@ -1765,7 +1765,7 @@ static inline void finish_task_switch(st finish_lock_switch(rq, prev); if (mm) mmdrop(mm); - if (unlikely(prev_state == EXIT_DEAD)) { + if (unlikely(prev_state == TASK_DEAD)) { /* * Remove function-return probe instances associated with this * task and put them back on the free list. @@ -5116,7 +5116,7 @@ static void migrate_dead(unsigned int de BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD); /* Cannot have done final schedule yet: would have vanished. */ - BUG_ON(p->state == EXIT_DEAD); + BUG_ON(p->state == TASK_DEAD); get_task_struct(p); --- 2.6.18-rc4/mm/oom_kill.c~3_rename 2006-08-26 21:34:04.000000000 +0400 +++ 2.6.18-rc4/mm/oom_kill.c 2006-08-26 22:34:35.000000000 +0400 @@ -206,7 +206,7 @@ static struct task_struct *select_bad_pr */ releasing = test_tsk_thread_flag(p, TIF_MEMDIE) || p->flags & PF_EXITING; - if (releasing && (p->state != EXIT_DEAD)) + if (releasing && (p->state != TASK_DEAD)) return ERR_PTR(-1UL); if (p->flags & PF_SWAPOFF) return p; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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