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| author |   Christoph Lameter <christoph@lameter.com> | 2005-06-24 23:13:50 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-25 17:10:13 -0700 |
| commit | 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 (patch) | |
| tree | d1e7c1e2e8902072042aefc3a7976b271cf76021 /kernel/signal.c | |
| parent | Merge master.kernel.org:/home/rmk/linux-2.6-serial (diff) | |
| download | linux-dev-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.tar.xz linux-dev-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.zip | |
[PATCH] Cleanup patch for process freezing
1. Establish a simple API for process freezing defined in linux/include/sched.h:
frozen(process) Check for frozen process
freezing(process) Check if a process is being frozen
freeze(process) Tell a process to freeze (go to refrigerator)
thaw_process(process) Restart process
frozen_process(process) Process is frozen now
2. Remove all references to PF_FREEZE and PF_FROZEN from all
kernel sources except sched.h
3. Fix numerous locations where try_to_freeze is manually done by a driver
4. Remove the argument that is no longer necessary from two function calls.
5. Some whitespace cleanup
6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
cleared before setting PF_FROZEN, recalc_sigpending does not check
PF_FROZEN).
This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index d1258729a5f9..ca1186eef938 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -213,7 +213,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) fastcall void recalc_sigpending_tsk(struct task_struct *t) { if (t->signal->group_stop_count > 0 || - (t->flags & PF_FREEZE) || + (freezing(t)) || PENDING(&t->pending, &t->blocked) || PENDING(&t->signal->shared_pending, &t->blocked)) set_tsk_thread_flag(t, TIF_SIGPENDING); @@ -2231,8 +2231,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese, current->state = TASK_INTERRUPTIBLE; timeout = schedule_timeout(timeout); - if (current->flags & PF_FREEZE) - refrigerator(PF_FREEZE); + try_to_freeze(); spin_lock_irq(¤t->sighand->siglock); sig = dequeue_signal(current, &these, &info); current->blocked = current->real_blocked; |