Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [PATCH V2 1/2] kobject: don't delay to cleanup module kobject | Date | Mon, 29 Nov 2021 11:45:08 +0800 |
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CONFIG_DEBUG_KOBJECT_RELEASE is used for debugging kobject release and cleanup issue. The module kobject is released after module_exit() returns. If this kobject is delayed too much, and may cause other kobjects cleaned up a bit earlier before freeing module, then real issue is hidden.
So don't delay module kobject's cleanup, meantime module kobject is always cleaned up synchronously, and CONFIG_DEBUG_KOBJECT_RELEASE is actually needless for module kobject.
Signed-off-by: Ming Lei <ming.lei@redhat.com> --- lib/kobject.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/lib/kobject.c b/lib/kobject.c index 4a56f519139d..b81319b0bd5a 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -16,6 +16,7 @@ #include <linux/stat.h> #include <linux/slab.h> #include <linux/random.h> +#include <linux/module.h> /** * kobject_namespace() - Return @kobj's namespace tag. @@ -727,6 +728,19 @@ static void kobject_release(struct kref *kref) struct kobject *kobj = container_of(kref, struct kobject, kref); #ifdef CONFIG_DEBUG_KOBJECT_RELEASE unsigned long delay = HZ + HZ * (get_random_int() & 0x3); + + /* + * Don't delay to release module kobject so that we can detect late + * kobject release more effectively because module unloading waits + * for completion of module kobject release, see mod_kobject_put. + * + * Meantime mod_kobject_put() always waits for completion of module + * kobject's release, CONFIG_DEBUG_KOBJECT_RELEASE is basically + * useless for debugging module kobject's release. + */ + if (kobj->ktype == &module_ktype) + delay = 0; + pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n", kobject_name(kobj), kobj, __func__, kobj->parent, delay); INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup); -- 2.31.1
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