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| author | Christoph Lameter <christoph@lameter.com> | 2005-06-25 10:13:50 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-26 04:10:13 +0400 |
| commit | 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 (patch) | |
| tree | d1e7c1e2e8902072042aefc3a7976b271cf76021 /mm | |
| parent | b3e112bcc19abd8e9657dca34a87316786e096f3 (diff) | |
| download | linux-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.tar.xz | |
[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 'mm')
| -rw-r--r-- | mm/pdflush.c | 2 | ||||
| -rw-r--r-- | mm/vmscan.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/mm/pdflush.c b/mm/pdflush.c index 38ce279cc8cd..d6781951267e 100644 --- a/mm/pdflush.c +++ b/mm/pdflush.c @@ -105,7 +105,7 @@ static int __pdflush(struct pdflush_work *my_work) spin_unlock_irq(&pdflush_lock); schedule(); - if (try_to_freeze(PF_FREEZE)) { + if (try_to_freeze()) { spin_lock_irq(&pdflush_lock); continue; } diff --git a/mm/vmscan.c b/mm/vmscan.c index 4b8e62a19370..1fa312a8db77 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1216,8 +1216,8 @@ static int kswapd(void *p) order = 0; for ( ; ; ) { unsigned long new_order; - if (current->flags & PF_FREEZE) - refrigerator(PF_FREEZE); + + try_to_freeze(); prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE); new_order = pgdat->kswapd_max_order; |