On Mon 02-01-12 11:43:27, Hugh Dickins wrote: > On Mon, 2 Jan 2012, Michal Hocko wrote: > > On Sat 31-12-11 23:30:38, Hugh Dickins wrote: > > > I never understood why we need a MEM_CGROUP_ZSTAT(mz, idx) macro > > > to obscure the LRU counts. For easier searching? So call it > > > lru_size rather than bare count (lru_length sounds better, but > > > would be wrong, since each huge page raises lru_size hugely). > > > > lru_size is unique at the global scope at the moment but this might > > change in the future. MEM_CGROUP_ZSTAT should be unique and so easier > > to grep or cscope. > > On the other hand lru_size sounds like a better name so I am all for > > renaming but we should make sure that we somehow get memcg into it > > (either to macro MEM_CGROUP_LRU_SIZE or get rid of macro and have > > memcg_lru_size field name - which is ugly long). > > I do disagree. You're asking to introduce artificial differences, > whereas generally we're trying to minimize the differences between > global and memcg. I am not asking to _introduce_ a new artificial difference I just wanted to make memcg lru accounting obvious. Currently, if I want to check that we account correctly I cscope/grep __mod_zone_page_state on the global level and we have MEM_CGROUP_ZSTAT for the memcg. If you remove the macro then it would be little bit harder (it won't actually because lru_size is unique at the moment it is just not that obvious). > I'm happy with the way mem_cgroup_zone_lruvec(), for example, returns > a pointer to the relevant structure, whether it's global or per-memcg, > and we then work with the contents of that structure, whichever it is: > lruvec in each case, not global_lruvec in one case and memcg_lruvec > in the other. Yes, I like it as well but we do not account the same way for memcg and global. Anyway, I do not have any strong opinion about the macro. Nevertheless, I definitely like the count->lru_size renaming. Thanks -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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>