On Tue, Jul 03, 2012 at 02:57:08PM +0900, KAMEZAWA Hiroyuki wrote: > (2012/06/28 20:04), Sha Zhengju wrote: > > From: Sha Zhengju <handai.szj@xxxxxxxxxx> > > > > This patch adds memcg routines to count dirty pages, which allows memory controller > > to maintain an accurate view of the amount of its dirty memory and can provide some > > info for users while group's direct reclaim is working. > > > > After Kame's commit 89c06bd5(memcg: use new logic for page stat accounting), we can > > use 'struct page' flag to test page state instead of per page_cgroup flag. But memcg > > has a feature to move a page from a cgroup to another one and may have race between > > "move" and "page stat accounting". So in order to avoid the race we have designed a > > bigger lock: > > > > mem_cgroup_begin_update_page_stat() > > modify page information -->(a) > > mem_cgroup_update_page_stat() -->(b) > > mem_cgroup_end_update_page_stat() > > > > It requires (a) and (b)(dirty pages accounting) can stay close enough. > > > > In the previous two prepare patches, we have reworked the vfs set page dirty routines > > and now the interfaces are more explicit: > > incrementing (2): > > __set_page_dirty > > __set_page_dirty_nobuffers > > decrementing (2): > > clear_page_dirty_for_io > > cancel_dirty_page > > > > > > Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx> > > Thank you. This seems much cleaner than expected ! very good. > > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> I have the same good feelings :) Acked-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>