On Sat, Dec 23, 2017 at 5:28 PM, Pravin Shedge <[email protected]> wrote: > The module auto-unload might seem like a nice optimization, but > it encourages inconsistent behaviour. And behaviour that is > different from all other normal modules. > > rbtree_test.c and percpu_test.c returns -EAGAIN from module_init() > on successful completion. Normal module return 0 on success but > returning -EAGAIN perform auto module unloading which seem like > a nice optimization but it brings inconsistent behaviour as well. > > I face the similar problem in my previous patch, "Paul Gortmaker" > gives nice review comment on module auto-unloading brings > inconsistent behaviour. > > Imagine something as simple as this: > > for i in $LIST ; do > modprobe $i > lsmod | grep -q $i > if [ $? != 0 ]; then echo Module $i is not present! ; fi > done > > OK, not ideal code, ignoring the modprobe return -- but what it reports > is true -- > rbtree_test.c and percpu_test.c test module (if it passed) will NOT be > present. > > All other modules from linux/lib/* follow the same semantics that > module_init() returns 0 on successful completion & let external entity > like rmmod do the module unloading task. >
Suggested-by: Andrew ... ? > Signed-off-by: Pravin Shedge <[email protected]> > --- > lib/percpu_test.c | 3 ++- > lib/rbtree_test.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/lib/percpu_test.c b/lib/percpu_test.c > index 0b5d14d..57a637b 100644 > --- a/lib/percpu_test.c > +++ b/lib/percpu_test.c > @@ -123,7 +123,8 @@ static int __init percpu_test_init(void) > preempt_enable(); > > pr_info("percpu test done\n"); > - return -EAGAIN; /* Fail will directly unload the module */ > + > + return 0; > } > > static void __exit percpu_test_exit(void) > diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c > index 7d36c1e..5c52112 100644 > --- a/lib/rbtree_test.c > +++ b/lib/rbtree_test.c > @@ -394,7 +394,7 @@ static int __init rbtree_test_init(void) > > kfree(nodes); > > - return -EAGAIN; /* Fail will directly unload the module */ > + return 0; > } > > static void __exit rbtree_test_exit(void) > -- > 2.7.4 > -- With Best Regards, Andy Shevchenko
