The patch titled
kill PF_DEAD flag
has been added to the -mm tree. Its filename is
kill-pf_dead-flag.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: kill PF_DEAD flag
From: Oleg Nesterov <oleg@xxxxxxxxxx>
After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we
don't need PF_DEAD any longer.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/sched.h | 1 -
kernel/exit.c | 6 ++----
kernel/sched.c | 16 ++++++++--------
mm/oom_kill.c | 4 ++--
4 files changed, 12 insertions(+), 15 deletions(-)
diff -puN include/linux/sched.h~kill-pf_dead-flag include/linux/sched.h
--- a/include/linux/sched.h~kill-pf_dead-flag
+++ a/include/linux/sched.h
@@ -1062,7 +1062,6 @@ static inline void put_task_struct(struc
/* Not implemented yet, only for 486*/
#define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
-#define PF_DEAD 0x00000008 /* Dead */
#define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
#define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
#define PF_DUMPCORE 0x00000200 /* dumped core */
diff -puN kernel/exit.c~kill-pf_dead-flag kernel/exit.c
--- a/kernel/exit.c~kill-pf_dead-flag
+++ a/kernel/exit.c
@@ -954,10 +954,8 @@ fastcall NORET_TYPE void do_exit(long co
if (tsk->splice_pipe)
__free_pipe_info(tsk->splice_pipe);
- /* PF_DEAD causes final put_task_struct after we schedule. */
preempt_disable();
- BUG_ON(tsk->flags & PF_DEAD);
- tsk->flags |= PF_DEAD;
+ /* causes final put_task_struct in finish_task_switch(). */
tsk->state = EXIT_DEAD;
schedule();
@@ -973,7 +971,7 @@ NORET_TYPE void complete_and_exit(struct
{
if (comp)
complete(comp);
-
+
do_exit(code);
}
diff -puN kernel/sched.c~kill-pf_dead-flag kernel/sched.c
--- a/kernel/sched.c~kill-pf_dead-flag
+++ a/kernel/sched.c
@@ -1745,27 +1745,27 @@ static inline void finish_task_switch(st
__releases(rq->lock)
{
struct mm_struct *mm = rq->prev_mm;
- unsigned long prev_task_flags;
+ long prev_state;
rq->prev_mm = NULL;
/*
* A task struct has one reference for the use as "current".
- * If a task dies, then it sets EXIT_ZOMBIE in tsk->exit_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_ZOMBIE must occur while the runqueue locks are
+ * If a task dies, then it sets EXIT_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
* 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.
* Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
*/
- prev_task_flags = prev->flags;
+ prev_state = prev->state;
finish_arch_switch(prev);
finish_lock_switch(rq, prev);
if (mm)
mmdrop(mm);
- if (unlikely(prev_task_flags & PF_DEAD)) {
+ if (unlikely(prev_state == EXIT_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->flags & PF_DEAD);
+ BUG_ON(p->state == EXIT_DEAD);
get_task_struct(p);
diff -puN mm/oom_kill.c~kill-pf_dead-flag mm/oom_kill.c
--- a/mm/oom_kill.c~kill-pf_dead-flag
+++ a/mm/oom_kill.c
@@ -227,8 +227,8 @@ static struct task_struct *select_bad_pr
releasing = test_tsk_thread_flag(p, TIF_MEMDIE) ||
p->flags & PF_EXITING;
if (releasing) {
- /* PF_DEAD tasks have already released their mm */
- if (p->flags & PF_DEAD)
+ /* TASK_DEAD tasks have already released their mm */
+ if (p->state == EXIT_DEAD)
continue;
if (p->flags & PF_EXITING && p == current) {
chosen = p;
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
for-2618-revert-drop-tasklist-lock-in-do_sched_setscheduler.patch
futex_find_get_task-remove-an-obscure-exit_zombie-check.patch
pid-implement-transfer_pid-and-use-it-to-simplify-de_thread.patch
pid-remove-temporary-debug-code-in-attach_pid.patch
rtmutex-clean-up-and-remove-some-extra-spinlocks.patch
rtmutex-clean-up-and-remove-some-extra-spinlocks-more.patch
elf_core_dump-dont-take-tasklist_lock.patch
elf_fdpic_core_dump-dont-take-tasklist_lock.patch
has_stopped_jobs-cleanup.patch
__dequeue_signal-cleanup.patch
do_sched_setscheduler-dont-take-tasklist_lock.patch
introduce-is_rt_policy-helper.patch
sched_setscheduler-fix-policy-checks.patch
reparent_to_init-use-has_rt_policy.patch
copy_process-cosmetic-ioprio-tweak.patch
futex_find_get_task-dont-take-tasklist_lock.patch
sys_get_robust_list-dont-take-tasklist_lock.patch
set-exit_dead-state-in-do_exit-not-in-schedule.patch
kill-pf_dead-flag.patch
introduce-task_dead-state.patch
simplify-pid-iterators.patch
pidhash-temporary-debug-checks.patch
-
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