From 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 Mon Sep 17 00:00:00 2001
From: Christoph Lameter <christoph@lameter.com>
Date: Fri, 24 Jun 2005 23:13:50 -0700
Subject: [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>
---
drivers/w1/w1.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'drivers/w1')
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index b460927ec32a..312cf3220f12 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -646,7 +646,7 @@ static int w1_control(void *data)
while (!control_needs_exit || have_to_wait) {
have_to_wait = 0;
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
if (signal_pending(current))
@@ -725,7 +725,7 @@ int w1_process(void *data)
allow_signal(SIGTERM);
while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
if (signal_pending(current))
--
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