2012/5/14 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>: > (2012/05/12 6:19), Andrew Morton wrote: > >> On Fri, 11 May 2012 18:47:06 +0900 >> KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: >> >>> From: Frederic Weisbecker <fweisbec@xxxxxxxxx> >>> >>> At killing res_counter which is a child of other counter, >>> we need to do >>> res_counter_uncharge(child, xxx) >>> res_counter_charge(parent, xxx) >>> >>> This is not atomic and wasting cpu. This patch adds >>> res_counter_uncharge_until(). This function's uncharge propagates >>> to ancestors until specified res_counter. >>> >>> res_counter_uncharge_until(child, parent, xxx) >>> >>> Now, ops is atomic and efficient. >>> >>> Changelog since v2 >>> - removed unnecessary lines. >>> - Fixed 'From' , this patch comes from his series. Please signed-off-by if good. >>> >>> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> >> >> Frederic's Signed-off-by: is unavaliable? >> > > I didn't add his Signed-off because I modified his orignal patch a little... > I dropped res_counter_charge_until() because it's not used in this series, > I have no justification for adding it. > The idea of res_counter_uncharge_until() is from his patch. The property of Signed-off-by is that as long as you carry/relay/modify a patch, you add your own signed-off-by. But you can't remove the signed off by of somebody in the chain. Even if you did a change in the patch, you need to preserve the chain. There may be some special cases with "Original-patch-from:" tags used when one heavily inspire from a patch without taking much of its original code. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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