From da39ba5e1d65e997a98f6eb93ba6e6eb505f6e3c Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 22 Jul 2008 19:24:25 -0500
Subject: module: don't use stop_machine for waiting rmmod
rmmod has a little-used "-w" option, meaning that instead of failing if the
module is in use, it should block until the module becomes unused.
In this case, we don't need to use stop_machine: Max Krasnyansky
indicated that would be useful for SystemTap which loads/unloads new
modules frequently.
Cc: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
kernel/module.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
(limited to 'kernel')
diff --git a/kernel/module.c b/kernel/module.c
index 5f80478b746..705e1d5d516 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -639,8 +639,8 @@ static int __try_stop_module(void *_sref)
{
struct stopref *sref = _sref;
- /* If it's not unused, quit unless we are told to block. */
- if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
+ /* If it's not unused, quit unless we're forcing. */
+ if (module_refcount(sref->mod) != 0) {
if (!(*sref->forced = try_force_unload(sref->flags)))
return -EWOULDBLOCK;
}
@@ -652,9 +652,16 @@ static int __try_stop_module(void *_sref)
static int try_stop_module(struct module *mod, int flags, int *forced)
{
- struct stopref sref = { mod, flags, forced };
+ if (flags & O_NONBLOCK) {
+ struct stopref sref = { mod, flags, forced };
- return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
+ return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
+ } else {
+ /* We don't need to stop the machine for this. */
+ mod->state = MODULE_STATE_GOING;
+ synchronize_sched();
+ return 0;
+ }
}
unsigned int module_refcount(struct module *mod)
--
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