On Thu 12-01-12 11:09:58, Ying Han wrote: > On Thu, Jan 12, 2012 at 4:54 AM, Michal Hocko <mhocko@xxxxxxx> wrote: > > On Wed 11-01-12 14:41:08, Ying Han wrote: > >> We have the nr_mlock stat both in meminfo as well as vmstat system wide, this > >> patch adds the mlock field into per-memcg memory stat. The stat itself enhances > >> the metrics exported by memcg, especially is used together with "uneivctable" > >> lru stat. > > > > Could you describe when the unevictable has such a different meaning than > > mlocked that it is unusable? > > The unevictable lru includes more than mlock()'d pages ( SHM_LOCK'd > etc). Like the following: Yes, I am aware of that. Maybe I wasn't clear enough in my question. I was rather interested _when_ it actually matters for your decisions about the setup. Those pages are not evictable anyway. > $ memtoy>shmem shm_400m 400m > $ memtoy>map shm_400m 0 400m > $ memtoy>touch shm_400m > memtoy: touched 102400 pages in 0.360 secs > $ memtoy>slock shm_400m > //meantime add some memory pressure. > > $ memtoy>file /export/hda3/file_512m > $ memtoy>map file_512m 0 512m shared > $ memtoy>lock file_512m > > $ cat /dev/cgroup/memory/B/memory.stat > mapped_file 956301312 > mlock 536870912 > unevictable 956203008 > > Here, mapped_file - mlock = 400M shm_lock'ed pages are included in > unevictable stat. > > Besides, not all mlock'ed pages get to unevictable lru at the first > place, and the same for the other way around. > > Thanks > > --Ying -- 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>