On Fri, 2011-03-04 at 10:10 +0100, Peter Zijlstra wrote: > 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? Also, there is no matching rmb,mb in nfs_wait_congested().. barrier always come in pairs. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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