lkml.org 
[lkml]   [2017]   [Dec]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 2/2] lib: Remove module auto-unloading which encourages inconsistent behaviour
On Sat, Dec 23, 2017 at 5:28 PM, Pravin Shedge
<pravin.shedge4linux@gmail.com> 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 <pravin.shedge4linux@gmail.com>
> ---
> 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

\
 
 \ /
  Last update: 2017-12-29 17:48    [W:0.037 / U:0.916 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site