[Patch] suspend.c washing

Frederick, Fabian (Fabian.Frederick@prov-liege.be)
Tue, 1 Jul 2003 16:06:17 +0200


Hi,

Here's a patch against 2.5.73 suspend.If someone has some seconds to
loose...

-replacing 'INTERESTING' macro by touchable_process fx
-moving flags declaration fx global
-yield after 'time_after'
-some code washing
-removing 'lock comment' we already do the read_lock() on
tasklist

--- ./../../linux-2.5.73/kernel/suspend.c 2003-06-22
20:32:38.000000000 +0200
+++ suspend.c 2003-07-01 15:55:50.000000000 +0200
@@ -29,6 +29,9 @@
* Alex Badea <vampire@go.ro>:
* Fixed runaway init
*
+ * Fabian Frédérick <ffrederick@users.sourceforge.net>
+ * Washing code in freeze_processes
+ *
* More state savers are welcome. Especially for the scsi layer...
*
* For TODOs,FIXMEs also look in Documentation/swsusp.txt
@@ -164,15 +167,6 @@
* Refrigerator and related stuff
*/

-#define INTERESTING(p) \
- /* We don't want to touch kernel_threads..*/ \
- if (p->flags & PF_IOTHREAD) \
- continue; \
- if (p == current) \
- continue; \
- if (p->state == TASK_ZOMBIE) \
- continue;
-
/* Refrigerator is place where frozen processes are stored :-). */
void refrigerator(unsigned long flag)
{
@@ -197,12 +191,20 @@
PRINTK("%s left refrigerator\n", current->comm);
current->state = save;
}
+int touchable_process (struct task_struct *p)
+{
+ return(!(p->flags & PF_IOTHREAD) || (p == current) || (p->state ==
TASK_ZOMBIE))
+
+}

-/* 0 = success, else # of processes that we failed to stop */
+/* Trying to freeze all processes without kernel threads, zombies and
current
+ * Returns 0 : Success
+ * # : Tasks we were unable to freeze
+ */
int freeze_processes(void)
{
- int todo;
- unsigned long start_time;
+ int todo;
+ unsigned long start_time, flags;
struct task_struct *g, *p;

printk( "Stopping tasks: " );
@@ -211,26 +213,23 @@
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- unsigned long flags;
- INTERESTING(p);
- if (p->flags & PF_FROZEN)
- continue;
-
- /* FIXME: smp problem here: we may not access other
process' flags
- without locking */
- p->flags |= PF_FREEZE;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- todo++;
+ if(touchable_process(p)){
+ if (p->flags & PF_FROZEN)
+ continue;
+ p->flags |= PF_FREEZE;
+ spin_lock_irqsave(&p->sighand->siglock,
flags);
+ signal_wake_up(p, 0);
+ spin_unlock_irqrestore(&p->sighand->siglock,
flags);
+ todo++;
+ }
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
- yield(); /* Yield is okay here */
if (time_after(jiffies, start_time + TIMEOUT)) {
printk( "\n" );
printk(KERN_ERR " stopping tasks failed (%d tasks
remaining)\n", todo );
return todo;
}
+ yield();
} while(todo);

printk( "|\n" );
@@ -245,12 +244,13 @@
printk( "Restarting tasks..." );
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- INTERESTING(p);
-
- if (p->flags & PF_FROZEN) p->flags &= ~PF_FROZEN;
- else
- printk(KERN_INFO " Strange, %s not stopped\n",
p->comm );
- wake_up_process(p);
+ if(touchable_process(p)){
+ if (p->flags & PF_FROZEN)
+ p->flags &= ~PF_FROZEN;
+ else
+ printk(KERN_INFO " Strange, %s not
stopped\n", p->comm );
+ wake_up_process(p);
+ }
} while_each_thread(g, p);

read_unlock(&tasklist_lock);

-
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