Hey, Vivek. On Wed, Apr 04, 2012 at 04:18:16PM -0400, Vivek Goyal wrote: > Hey how about reconsidering my other proposal for which I had posted > the patches. And that is keep throttling still at device level. Reads > and direct IO get throttled asynchronously but buffered writes get > throttled synchronously. > > Advantages of this scheme. > > - There are no separate knobs. > > - All the IO (read, direct IO and buffered write) is controlled using > same set of knobs and goes in queue of same cgroup. > > - Writeback logic has no knowledge of throttling. It just invokes a > hook into throttling logic of device queue. > > I guess this is a hybrid of active writeback throttling and back pressure > mechanism. > > But it still does not solve the NFS issue as well as for direct IO, > filesystems still can get serialized, so metadata issue still needs to > be resolved. So one can argue that why not go for full "back pressure" > method, despite it being more complex. > > Here is the link, just to refresh the memory. Something to keep in mind > while assessing alternatives. > > https://lkml.org/lkml/2011/6/28/243 Hmmm... so, this only works for blk-throttle and not with the weight. How do you manage interaction between buffered writes and direct writes for the same cgroup? Thanks. -- tejun -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>