On Fri, 2011-03-04 at 10:01 +0800, Wu Fengguang wrote:

                        clear_bdi_congested(bdi, BLK_RW_SYNC);
                        /*
                         * On the following wake_up(), nfs_wait_congested()
                         * will see the cleared bit and quit.
                         */
                        smp_mb__after_clear_bit();
                }
                if (waitqueue_active(&wqh[BLK_RW_SYNC]))
                        wake_up(&wqh[BLK_RW_SYNC]); 

If I tell you that: try_to_wake_up() implies an smp_wmb(), do you then
still need this?

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>