On Thu, Sep 20, 2007 at 03:08:42PM +0200, Nadia Derbey wrote: ... > So, here is the ipc_lock_by_ptr() status: > 1) do_msgsnd(), semctl_main(GETALL), semctl_main(SETALL) and find_undo() > call it inside a refcounting. > ==> no rcu read section needed. > > 2) *_exit_ns(), ipc_findkey() and sysvipc_find_ipc() call it under the > ipc_ids mutex lock. > ==> no rcu read section needed. > > 3) do_msgrcv() is the only path where ipc_lock_by_ptr() is not called > under refcounting > ==> rcu read section + some more checks needed once the spnlock is > taken. > > So I completely agree with you: we might remove the rcu_read_lock() from > the ipc_lock_by_ptr() and explicitley call it when needed (actually, it > is already explicitly called in do_msgrcv()).
Impossible! I've to look at this once more in the evening (and try to recall what I've seen yesterday and forgotten today...). Cheers, Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
