averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-09-05 08:44:14 +02:00
Code Issues Packages Projects Releases Wiki Activity

module/dups: Inform duplicate requests about the result directly

Browse Source 
When kmod_dup_request_announce() announces the completion of
a request_module() call to duplicate waiters, it queues a work item to
invoke kmod_dup_request_complete(), and only that function calls
complete_all().

This adds an arbitrary delay that is unnecessary and provides little
benefit. Call complete_all() directly from kmod_dup_request_announce()
instead.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
This commit is contained in:
Petr Pavlu
2026-08-06 13:29:03 +02:00
parent da991304c9
commit d258ed8a86
1 changed files with 9 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/module/dups.c
+9 -34
View File
@@ -48,7 +48,6 @@ struct kmod_dup_req {
struct list_head list;
char name[MODULE_NAME_LEN];
struct completion first_req_done;
struct work_struct complete_work;
struct delayed_work delete_work;
int dup_ret;
};
@@ -93,29 +92,6 @@ static void kmod_dup_request_delete(struct work_struct *work)
kfree(kmod_req);
}
static void kmod_dup_request_complete(struct work_struct *work)
{
struct kmod_dup_req *kmod_req;
kmod_req = container_of(work, struct kmod_dup_req, complete_work);
/*
* This will ensure that the kernel will let all the waiters get
* informed its time to check the return value. It's time to
* go home.
*/
complete_all(&kmod_req->first_req_done);
/*
* Now that we have allowed prior request_module() calls to go on
* with life, let's schedule deleting this entry. We don't have
* to do it right away, but we *eventually* want to do it so to not
* let this linger forever as this is just a boot optimization for
* possible abuses of vmalloc() incurred by finit_module() thrashing.
*/
queue_delayed_work(system_dfl_wq, &kmod_req->delete_work, 60 * HZ);
}
bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret)
{
struct kmod_dup_req *kmod_req, *new_kmod_req;
@@ -130,7 +106,6 @@ bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret)
return false;
strscpy(new_kmod_req->name, module_name);
INIT_WORK(&new_kmod_req->complete_work, kmod_dup_request_complete);
INIT_DELAYED_WORK(&new_kmod_req->delete_work, kmod_dup_request_delete);
init_completion(&new_kmod_req->first_req_done);
@@ -230,17 +205,17 @@ void kmod_dup_request_announce(char *module_name, int ret)
kmod_req->dup_ret = ret;
/* Inform all duplicate waiters to check the return value. */
complete_all(&kmod_req->first_req_done);
/*
* If we complete() here we may allow duplicate threads
* to continue before the first one that submitted the
* request. We're in no rush also, given that each and
* every bounce back to userspace is slow we avoid that
* with a slight delay here. So queueue up the completion
* and let duplicates suffer, just wait a tad bit longer.
* There is no rush. But we also don't want to hold the
* caller up forever or introduce any boot delays.
* Now that we have allowed prior request_module() calls to go on
* with life, let's schedule deleting this entry. We don't have
* to do it right away, but we *eventually* want to do it so to not
* let this linger forever as this is just a boot optimization for
* possible abuses of vmalloc() incurred by finit_module() thrashing.
*/
queue_work(system_dfl_wq, &kmod_req->complete_work);
queue_delayed_work(system_dfl_wq, &kmod_req->delete_work, 60 * HZ);
out:
mutex_unlock(&kmod_dup_mutex);