* Andrea Righi <arighi@xxxxxxxxxxx> [2010-03-04 11:40:11]: > Control the maximum amount of dirty pages a cgroup can have at any given time. > > Per cgroup dirty limit is like fixing the max amount of dirty (hard to reclaim) > page cache used by any cgroup. So, in case of multiple cgroup writers, they > will not be able to consume more than their designated share of dirty pages and > will be forced to perform write-out if they cross that limit. > > The overall design is the following: > > - account dirty pages per cgroup > - limit the number of dirty pages via memory.dirty_ratio / memory.dirty_bytes > and memory.dirty_background_ratio / memory.dirty_background_bytes in > cgroupfs > - start to write-out (background or actively) when the cgroup limits are > exceeded > > This feature is supposed to be strictly connected to any underlying IO > controller implementation, so we can stop increasing dirty pages in VM layer > and enforce a write-out before any cgroup will consume the global amount of > dirty pages defined by the /proc/sys/vm/dirty_ratio|dirty_bytes and > /proc/sys/vm/dirty_background_ratio|dirty_background_bytes limits. > > Changelog (v3 -> v4) > ~~~~~~~~~~~~~~~~~~~~~~ > * handle the migration of tasks across different cgroups > NOTE: at the moment we don't move charges of file cache pages, so this > functionality is not immediately necessary. However, since the migration of > file cache pages is in plan, it is better to start handling file pages > anyway. > * properly account dirty pages in nilfs2 > (thanks to Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>) > * lockless access to dirty memory parameters > * fix: page_cgroup lock must not be acquired under mapping->tree_lock > (thanks to Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> and > KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>) > * code restyling > This seems to be converging, what sort of tests are you running on this patchset? -- Three Cheers, Balbir -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>