Messages in this thread | | | Date | Sun, 21 Nov 2010 12:37:26 -0500 | From | Ted Ts'o <> | Subject | Re: [BUG?] [Ext4] INFO: suspicious rcu_dereference_check() usage |
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On Mon, Nov 22, 2010 at 12:39:49AM +0900, Minchan Kim wrote: > > I think it's no problem. > > That's because migration always holds lock_page on the file page. > So the page couldn't remove from radix.
It may be "ok" in that it won't cause a race, but it still leaves an unsightly warning if LOCKDEP is enabled, and LOCKDEP warnings will cause /proc_lock_stat to be disabled. So I think it still needs to be fixed by adding rcu_read_lock()/rcu_read_unlock() to migrate_page_move_mapping().
- Ted
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