| Message ID | 20090623150358.22490.24818.stgit@localhost |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Jun 23, 2009 at 05:03:59PM +0200, Jesper Dangaard Brouer wrote: > 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? Yes, that's correct. Thanks; I've included this in the ext4 patch queue. - Ted -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 519a0a6..e271a9e 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2902,8 +2902,10 @@ int __init init_ext4_mballoc(void) void exit_ext4_mballoc(void) { - /* XXX: synchronize_rcu(); */ + /* Wait for completion of call_rcu()'s on ext4_pspace_cachep */ + rcu_barrier(); kmem_cache_destroy(ext4_pspace_cachep); + kmem_cache_destroy(ext4_ac_cachep); kmem_cache_destroy(ext4_free_ext_cachep); }
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(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html