Re: [PATCH v3] kernel/module: Reschedule while waiting for modules to finish loading

From: Jessica Yu
Date: Wed May 01 2019 - 03:56:02 EST

+++ Prarit Bhargava [30/04/19 18:22 -0400]:
On a s390 z14 LAR with 2 cpus about stalls about 3% of the time while
loading the s390_trng.ko module.

Add a reschedule point to the loop that waits for modules to complete

v3: cleanup Fixes line.

Thanks, this patch has been re-applied to modules-next.


Reported-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Fixes: f9a75c1d717f ("modules: Only return -EEXIST for modules that have finished loading")
Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Jessica Yu <jeyu@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
kernel/module.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/module.c b/kernel/module.c
index 410eeb7e4f1d..48748cfec991 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3585,6 +3585,7 @@ static int add_unformed_module(struct module *mod)
if (err)
goto out_unlocked;
+ cond_resched();
goto again;
err = -EEXIST;