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authorDavid Howells <dhowells@redhat.com>2009-12-01 13:52:08 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-01 07:35:11 -0800
commitfa1dae4906982b5d896c07613b1fe42456133b1c (patch)
tree027dec5baeedbe25a7b645311b530a06d78b36f3
parent6f054164322bc6c1233402b9ed6b40d4af39a98f (diff)
SLOW_WORK: Fix the CONFIG_MODULES=n case
Commits 3d7a641 ("SLOW_WORK: Wait for outstanding work items belonging to a module to clear") introduced some code to make sure that all of a module's slow-work items were complete before that module was removed, and commit 3bde31a ("SLOW_WORK: Allow a requeueable work item to sleep till the thread is needed") further extended that, breaking it in the process if CONFIG_MODULES=n: CC kernel/slow-work.o kernel/slow-work.c: In function 'slow_work_execute': kernel/slow-work.c:313: error: 'slow_work_thread_processing' undeclared (first use in this function) kernel/slow-work.c:313: error: (Each undeclared identifier is reported only once kernel/slow-work.c:313: error: for each function it appears in.) kernel/slow-work.c: In function 'slow_work_wait_for_items': kernel/slow-work.c:950: error: 'slow_work_unreg_sync_lock' undeclared (first use in this function) kernel/slow-work.c:951: error: 'slow_work_unreg_wq' undeclared (first use in this function) kernel/slow-work.c:961: error: 'slow_work_unreg_work_item' undeclared (first use in this function) kernel/slow-work.c:974: error: 'slow_work_unreg_module' undeclared (first use in this function) kernel/slow-work.c:977: error: 'slow_work_thread_processing' undeclared (first use in this function) make[1]: *** [kernel/slow-work.o] Error 1 Fix this by: (1) Extracting the bits of slow_work_execute() that are contingent on CONFIG_MODULES, and the bits that should be, into inline functions and placing them into the #ifdef'd section that defines the relevant variables and adding stubs for moduleless kernels. This allows the removal of some #ifdefs. (2) #ifdef'ing out the contents of slow_work_wait_for_items() in moduleless kernels. The four functions related to handling module unloading synchronisation (and their associated variables) could be offloaded into a separate .c file, but each function is only used once and three of them are tiny, so doing so would prevent them from being inlined. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/slow-work.c46
1 files changed, 29 insertions, 17 deletions
diff --git a/kernel/slow-work.c b/kernel/slow-work.c
index da94f3c101a..b5c17f15f9d 100644
--- a/kernel/slow-work.c
+++ b/kernel/slow-work.c
@@ -109,6 +109,30 @@ static struct module *slow_work_unreg_module;
static struct slow_work *slow_work_unreg_work_item;
static DECLARE_WAIT_QUEUE_HEAD(slow_work_unreg_wq);
static DEFINE_MUTEX(slow_work_unreg_sync_lock);
+
+static void slow_work_set_thread_processing(int id, struct slow_work *work)
+{
+ if (work)
+ slow_work_thread_processing[id] = work->owner;
+}
+static void slow_work_done_thread_processing(int id, struct slow_work *work)
+{
+ struct module *module = slow_work_thread_processing[id];
+
+ slow_work_thread_processing[id] = NULL;
+ smp_mb();
+ if (slow_work_unreg_work_item == work ||
+ slow_work_unreg_module == module)
+ wake_up_all(&slow_work_unreg_wq);
+}
+static void slow_work_clear_thread_processing(int id)
+{
+ slow_work_thread_processing[id] = NULL;
+}
+#else
+static void slow_work_set_thread_processing(int id, struct slow_work *work) {}
+static void slow_work_done_thread_processing(int id, struct slow_work *work) {}
+static void slow_work_clear_thread_processing(int id) {}
#endif
/*
@@ -197,9 +221,6 @@ static unsigned slow_work_calc_vsmax(void)
*/
static noinline bool slow_work_execute(int id)
{
-#ifdef CONFIG_MODULES
- struct module *module;
-#endif
struct slow_work *work = NULL;
unsigned vsmax;
bool very_slow;
@@ -236,10 +257,7 @@ static noinline bool slow_work_execute(int id)
very_slow = false; /* avoid the compiler warning */
}
-#ifdef CONFIG_MODULES
- if (work)
- slow_work_thread_processing[id] = work->owner;
-#endif
+ slow_work_set_thread_processing(id, work);
if (work) {
slow_work_mark_time(work);
slow_work_begin_exec(id, work);
@@ -287,15 +305,7 @@ static noinline bool slow_work_execute(int id)
/* sort out the race between module unloading and put_ref() */
slow_work_put_ref(work);
-
-#ifdef CONFIG_MODULES
- module = slow_work_thread_processing[id];
- slow_work_thread_processing[id] = NULL;
- smp_mb();
- if (slow_work_unreg_work_item == work ||
- slow_work_unreg_module == module)
- wake_up_all(&slow_work_unreg_wq);
-#endif
+ slow_work_done_thread_processing(id, work);
return true;
@@ -310,7 +320,7 @@ auto_requeue:
else
list_add_tail(&work->link, &slow_work_queue);
spin_unlock_irq(&slow_work_queue_lock);
- slow_work_thread_processing[id] = NULL;
+ slow_work_clear_thread_processing(id);
return true;
}
@@ -943,6 +953,7 @@ EXPORT_SYMBOL(slow_work_register_user);
*/
static void slow_work_wait_for_items(struct module *module)
{
+#ifdef CONFIG_MODULES
DECLARE_WAITQUEUE(myself, current);
struct slow_work *work;
int loop;
@@ -989,6 +1000,7 @@ static void slow_work_wait_for_items(struct module *module)
remove_wait_queue(&slow_work_unreg_wq, &myself);
mutex_unlock(&slow_work_unreg_sync_lock);
+#endif /* CONFIG_MODULES */
}
/**