On Thu, Feb 2, 2012 at 6:38 PM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Thu, 2 Feb 2012 17:37:13 -0800 > Ying Han <yinghan@xxxxxxxxxx> wrote: > >> In v3.3-rc1, the global LRU has been removed with commit >> "mm: make per-memcg LRU lists exclusive". The patch fixes up the memcg docs. >> >> Signed-off-by: Ying Han <yinghan@xxxxxxxxxx> >> --- >> Documentation/cgroups/memory.txt | 25 ++++++++++++------------- >> 1 files changed, 12 insertions(+), 13 deletions(-) >> >> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt >> index 4c95c00..847a2a4 100644 >> --- a/Documentation/cgroups/memory.txt >> +++ b/Documentation/cgroups/memory.txt >> @@ -34,8 +34,7 @@ Current Status: linux-2.6.34-mmotm(development version of 2010/April) >> >> Features: >> - accounting anonymous pages, file caches, swap caches usage and limiting them. >> - - private LRU and reclaim routine. (system's global LRU and private LRU >> - work independently from each other) >> + - pages are linked to per-memcg LRU exclusively, and there is no global LRU. >> - optionally, memory+swap usage can be accounted and limited. >> - hierarchical accounting >> - soft limit >> @@ -154,7 +153,7 @@ updated. page_cgroup has its own LRU on cgroup. >> 2.2.1 Accounting details >> >> All mapped anon pages (RSS) and cache pages (Page Cache) are accounted. >> -Some pages which are never reclaimable and will not be on the global LRU >> +Some pages which are never reclaimable and will not be on the LRU >> are not accounted. We just account pages under usual VM management. >> >> RSS pages are accounted at page_fault unless they've already been accounted >> @@ -209,19 +208,19 @@ In this case, setting memsw.limit_in_bytes=3G will prevent bad use of swap. >> By using memsw limit, you can avoid system OOM which can be caused by swap >> shortage. >> >> -* why 'memory+swap' rather than swap. >> -The global LRU(kswapd) can swap out arbitrary pages. Swap-out means >> -to move account from memory to swap...there is no change in usage of >> -memory+swap. In other words, when we want to limit the usage of swap without >> -affecting global LRU, memory+swap limit is better than just limiting swap from >> -OS point of view. >> - >> * What happens when a cgroup hits memory.memsw.limit_in_bytes >> When a cgroup hits memory.memsw.limit_in_bytes, it's useless to do swap-out >> in this cgroup. Then, swap-out will not be done by cgroup routine and file >> -caches are dropped. But as mentioned above, global LRU can do swapout memory >> -from it for sanity of the system's memory management state. You can't forbid >> -it by cgroup. >> +caches are dropped. >> + >> +TODO: >> +* use 'memory+swap' rather than swap was due to existence of global LRU. It can >> +swap out arbitrary pages. Swap-out means to move account from memory to swap... >> +there is no change in usage of memory+swap. In other words, when we want to >> +limit the usage of swap without affecting global LRU, memory+swap limit is >> +better than just limiting swap from OS point of view. However, the global LRU >> +has been removed now and all pages are linked in private LRU. We might want to >> +revisit this in the future. >> > > Could you devide this memory+swap discussion to otehr patch ? yes, will do that. > > Do you want to do memory locking by setting swap_limit=0 ? hmm, not sure what do you mean here? --Ying > > 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