On Fri, 13 May 2011 01:47:42 -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> Seems simple and handy enough. Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
