user/sven/linux.git/include/linux/res_counter.h, branch v3.2.31

memcg: simplify the way memory limits are checked

2011-03-24T02:46:23Z

Since transparent huge pages, checking whether memory cgroups are below their limits is no longer enough, but the actual amount of chargeable space is important. To not have more than one limit-checking interface, replace memory_cgroup_check_under_limit() and memory_cgroup_check_margin() with a single memory_cgroup_margin() that returns the chargeable space and leaves the comparison to the callsite. Soft limits are now checked the other way round, by using the already existing function that returns the amount by which soft limits are exceeded: res_counter_soft_limit_excess(). Also remove all the corresponding functions on the res_counter side that are now no longer used. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Acked-by: Balbir Singh Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: soft limit reclaim should end at limit not below

2011-03-24T02:46:23Z

Soft limit reclaim continues until the usage is below the current soft limit, but the documented semantics are actually that soft limit reclaim will push usage back until the soft limits are met again. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Acked-by: Balbir Singh Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: prevent endless loop when charging huge pages to near-limit group

2011-02-03T00:03:19Z

If reclaim after a failed charging was unsuccessful, the limits are checked again, just in case they settled by means of other tasks. This is all fine as long as every charge is of size PAGE_SIZE, because in that case, being below the limit means having at least PAGE_SIZE bytes available. But with transparent huge pages, we may end up in an endless loop where charging and reclaim fail, but we keep going because the limits are not yet exceeded, although not allowing for a huge page. Fix this up by explicitely checking for enough room, not just whether we are within limits. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Minchan Kim Cc: Balbir Singh Cc: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: some modification to softlimit under hierarchical memory reclaim.

2009-10-01T23:11:13Z

This patch clean up/fixes for memcg's uncharge soft limit path. Problems: Now, res_counter_charge()/uncharge() handles softlimit information at charge/uncharge and softlimit-check is done when event counter per memcg goes over limit. Now, event counter per memcg is updated only when memory usage is over soft limit. Here, considering hierarchical memcg management, ancesotors should be taken care of. Now, ancerstors(hierarchy) are handled in charge() but not in uncharge(). This is not good. Prolems: 1. memcg's event counter incremented only when softlimit hits. That's bad. It makes event counter hard to be reused for other purpose. 2. At uncharge, only the lowest level rescounter is handled. This is bug. Because ancesotor's event counter is not incremented, children should take care of them. 3. res_counter_uncharge()'s 3rd argument is NULL in most case. ops under res_counter->lock should be small. No "if" sentense is better. Fixes: * Removed soft_limit_xx poitner and checks in charge and uncharge. Do-check-only-when-necessary scheme works enough well without them. * make event-counter of memcg incremented at every charge/uncharge. (per-cpu area will be accessed soon anyway) * All ancestors are checked at soft-limit-check. This is necessary because ancesotor's event counter may never be modified. Then, they should be checked at the same time. Reviewed-by: Daisuke Nishimura Signed-off-by: KAMEZAWA Hiroyuki Cc: Paul Menage Cc: Li Zefan Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory controller: soft limit organize cgroups

2009-09-24T14:20:59Z

Organize cgroups over soft limit in a RB-Tree Introduce an RB-Tree for storing memory cgroups that are over their soft limit. The overall goal is to 1. Add a memory cgroup to the RB-Tree when the soft limit is exceeded. We are careful about updates, updates take place only after a particular time interval has passed 2. We remove the node from the RB-Tree when the usage goes below the soft limit The next set of patches will exploit the RB-Tree to get the group that is over its soft limit by the largest amount and reclaim from it, when we face memory contention. [hugh.dickins@tiscali.co.uk: CONFIG_CGROUP_MEM_RES_CTLR=y CONFIG_PREEMPT=y fails to boot] Signed-off-by: Balbir Singh Signed-off-by: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: KOSAKI Motohiro Signed-off-by: Hugh Dickins Cc: Jiri Slaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory controller: soft limit interface

2009-09-24T14:20:59Z

Add an interface to allow get/set of soft limits. Soft limits for memory plus swap controller (memsw) is currently not supported. Resource counters have been enhanced to support soft limits and new type RES_SOFT_LIMIT has been added. Unlike hard limits, soft limits can be directly set and do not need any reclaim or checks before setting them to a newer value. Kamezawa-San raised a question as to whether soft limit should belong to res_counter. Since all resources understand the basic concepts of hard and soft limits, it is justified to add soft limits here. Soft limits are a generic resource usage feature, even file system quotas support soft limits. Signed-off-by: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: add interface to reset limits

2009-06-18T20:03:48Z

We don't have an interface to reset mem.limit or memsw.limit now. This patch allows to reset mem.limit or memsw.limit when they are being set to -1. Signed-off-by: Daisuke Nishimura Cc: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Li Zefan Cc: Dhaval Giani Cc: YAMAMOTO Takashi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cgroups: consolidate cgroup documents

2009-01-16T00:39:37Z

Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: Li Zefan Acked-by: KAMEZAWA Hiroyuki Acked-by: Balbir Singh Acked-by: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: memory cgroup resource counters for hierarchy

2009-01-08T16:31:05Z

Add support for building hierarchies in resource counters. Cgroups allows us to build a deep hierarchy, but we currently don't link the resource counters belonging to the memory controller control groups, in the same fashion as the corresponding cgroup entries in the cgroup hierarchy. This patch provides the infrastructure for resource counters that have the same hiearchy as their cgroup counter parts. These set of patches are based on the resource counter hiearchy patches posted by Pavel Emelianov. NOTE: Building hiearchies is expensive, deeper hierarchies imply charging the all the way up to the root. It is known that hiearchies are expensive, so the user needs to be careful and aware of the trade-offs before creating very deep ones. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Balbir Singh Cc: YAMAMOTO Takashi Cc: Paul Menage Cc: Li Zefan Cc: David Rientjes Cc: Pavel Emelianov Cc: Dhaval Giani Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

res_counter: fix off-by-one bug in setting limit

2008-09-05T21:39:37Z

I found we can no longer set limit to 0 with 2.6.27-rcX: # mount -t cgroup -omemory xxx /mnt # mkdir /mnt/0 # echo 0 > /mnt/0/memory.limit_in_bytes bash: echo: write error: Device or resource busy It turned out 'limit' can't be set to 'usage', which is wrong IMO. Signed-off-by: Li Zefan Acked-by: KAMEZAWA Hiroyuki Acked-by: Balbir Singh Acked-by: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds