Re: [PATCH 07/10] decnet: Use rcu_barrier() on module unload.

Jesper Dangaard Brouer
2009-06-27T07:35:17Z

On Fri, 2009-06-26 at 20:15 -0700, Christian Kujau wrote:
> On Fri, 26 Jun 2009, Jesper Dangaard Brouer wrote:
> > I'll resubmit the patches to you and netdev, to limit the spam effect...
>
> Out of curiosity: why was linux-ext4 Cc'ed on these rcu_barrier patches
> (but not other fs-lists but linux-nfs)? I did not see any ../fs/ext4/
> changes.

There was a ../fs/ext4/ change in patch [01/10].

Titled: "ext4: Use rcu_barrier() on module unload"

git show --stat d6a4ea73b7e8779607dd48735d9a9c521c890857
commit d6a4ea73b7e8779607dd48735d9a9c521c890857
Author: Jesper Dangaard Brouer <hawk@comx.dk>
Date: Tue Jun 23 15:40:54 2009 +0200

ext4: Use rcu_barrier() on module unload.

The ext4 module uses rcu_call() thus it should use rcu_barrier()on
module unload.

The kmem cache ext4_pspace_cachep is sometimes free'ed using
call_rcu() callbacks. Thus, we must wait for completion of call_rcu()
before doing kmem_cache_destroy().

I have difficult determining if no new call_rcu() callbacks can be envoked.
Would the maintainer please verify this?

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>

fs/ext4/mballoc.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

--
Med venlig hilsen / Best regards
Jesper Brouer
ComX Networks A/S
Linux Network developer
Cand. Scient Datalog / MSc.
Author of http://adsl-optimizer.dk
LinkedIn: http://www.linkedin.com/in/brouer