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: $ 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>