Hi Christoph: On Thu, Mar 17, 2011 at 8:51 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Thu, Mar 17, 2011 at 08:46:23AM -0700, Curt Wohlgemuth wrote: >> But if one of one's goals is to provide some sort of disk isolation based on >> cgroup parameters, than having at most one stream of write requests >> effectively neuters the IO scheduler. > > If you use any kind of buffered I/O you already fail in that respect. > Writeback from balance_dirty_page really is just the wort case right now > with more I/O supposed to be handled by the background threads. So if > you want to implement isolation properly you need to track the > originator of the I/O between the copy to the pagecache and actual > writeback. Which is indeed part of the patchset I referred to above ("[RFC] [PATCH 0/6] Provide cgroup isolation for buffered writes", https://lkml.org/lkml/2011/3/8/332 ). Thanks, Curt -- 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