On Wed, 17 Aug 2011 09:14:57 -0700 Greg Thelen <gthelen@xxxxxxxxxx> wrote: > Create the mem_cgroup_mark_inode_dirty() routine, which is called when > an inode is marked dirty. In kernels without memcg, this is an inline > no-op. > > Add i_memcg field to struct address_space. When an inode is marked > dirty with mem_cgroup_mark_inode_dirty(), the css_id of current memcg is > recorded in i_memcg. Per-memcg writeback (introduced in a latter > change) uses this field to isolate inodes associated with a particular > memcg. > > The type of i_memcg is an 'unsigned short' because it stores the css_id > of the memcg. Using a struct mem_cgroup pointer would be larger and > also create a reference on the memcg which would hang memcg rmdir > deletion. Usage of a css_id is not a reference so cgroup deletion is > not affected. The memcg can be deleted without cleaning up the i_memcg > field. When a memcg is deleted its pages are recharged to the cgroup > parent, and the related inode(s) are marked as shared thus > disassociating the inodes from the deleted cgroup. > > A mem_cgroup_mark_inode_dirty() tracepoint is also included to allow for > easier understanding of memcg writeback operation. > > Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > --- > Changelog since v8: > - Use I_MEMCG_SHARED when initializing i_memcg. > > - Use 'memcg' rather than 'mem' for local variables. This is consistent with > other memory controller code. > > - The logic in mem_cgroup_update_page_stat() and mem_cgroup_move_account() which > marks inodes I_MEMCG_SHARED is now part of this patch. This makes more sense > because this is that patch that introduces that shared-inode concept. > yes, this makes the patch clearer. Thanks, -Kame -- 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>