We're trying to get rid of as much as possible tasklist walks, or at
least moving them to core code. This patch falls into the second
category.
Instead of walking the tasklist in cfq-iosched move that into
elv_unregister. The added benefit is that with this change the as
ioscheduler might be might unloadable more easily aswell.
The new code uses read_lock instead of read_lock_irq because the
tasklist_lock only needs irq disabling for writers.
Signed-off-by: Christoph Hellwig <[email protected]>
Index: linux-2.6/drivers/block/cfq-iosched.c
===================================================================
--- linux-2.6.orig/drivers/block/cfq-iosched.c 2005-08-11 16:45:55.000000000 +0200
+++ linux-2.6/drivers/block/cfq-iosched.c 2005-08-14 12:09:17.000000000 +0200
@@ -2609,28 +2609,8 @@
static void __exit cfq_exit(void)
{
- struct task_struct *g, *p;
- unsigned long flags;
-
- read_lock_irqsave(&tasklist_lock, flags);
-
- /*
- * iterate each process in the system, removing our io_context
- */
- do_each_thread(g, p) {
- struct io_context *ioc = p->io_context;
-
- if (ioc && ioc->cic) {
- ioc->cic->exit(ioc->cic);
- cfq_free_io_context(ioc->cic);
- ioc->cic = NULL;
- }
- } while_each_thread(g, p);
-
- read_unlock_irqrestore(&tasklist_lock, flags);
-
- cfq_slab_kill();
elv_unregister(&iosched_cfq);
+ cfq_slab_kill();
}
module_init(cfq_init);
Index: linux-2.6/drivers/block/elevator.c
===================================================================
--- linux-2.6.orig/drivers/block/elevator.c 2005-08-11 16:45:55.000000000 +0200
+++ linux-2.6/drivers/block/elevator.c 2005-08-14 12:12:35.000000000 +0200
@@ -572,6 +572,27 @@
void elv_unregister(struct elevator_type *e)
{
+ struct task_struct *g, *p;
+
+ /*
+ * Iterate every thread in the process to remove the io contexts.
+ */
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ struct io_context *ioc = p->io_context;
+ if (ioc && ioc->cic) {
+ ioc->cic->exit(ioc->cic);
+ ioc->cic->dtor(ioc->cic);
+ ioc->cic = NULL;
+ }
+ if (ioc && ioc->aic) {
+ ioc->aic->exit(ioc->aic);
+ ioc->aic->dtor(ioc->aic);
+ ioc->aic = NULL;
+ }
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+
spin_lock_irq(&elv_list_lock);
list_del_init(&e->list);
spin_unlock_irq(&elv_list_lock);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |