Lines Matching +full:charging +full:- +full:algorithm
18 we call it "memory cgroup". When you see git-log and source code, you'll
30 Memory-hungry applications can be isolated and limited to a smaller
42 Current Status: linux-2.6.34-mmotm(development version of 2010/April)
46 - accounting anonymous pages, file caches, swap caches usage and limiting them.
47 - pages are linked to per-memcg LRU exclusively, and there is no global LRU.
48 - optionally, memory+swap usage can be accounted and limited.
49 - hierarchical accounting
50 - soft limit
51 - moving (recharging) account at moving a task is selectable.
52 - usage threshold notifier
53 - memory pressure notifier
54 - oom-killer disable knob and oom-notifier
55 - Root cgroup has no limit controls.
59 <cgroup-v1-memory-kernel-extension>`)
148 -----------
156 ---------------
158 .. code-block::
161 +--------------------+
164 +--------------------+
167 +---------------+ | +---------------+
170 +---------------+ | +---------------+
172 + --------------+
174 +---------------+ +------+--------+
175 | page +----------> page_cgroup|
177 +---------------+ +---------------+
192 If everything goes well, a page meta-data-structure called page_cgroup is
194 (*) page_cgroup structure is allocated at boot/memory-hotplug time.
197 ------------------------
212 A swapped-in page is accounted after adding into swapcache.
214 Note: The kernel does swapin-readahead and reads multiple swaps at once.
220 Note: we just account pages-on-LRU because our purpose is to control amount
221 of used pages; not-on-LRU pages tend to be out-of-control from VM view.
224 --------------------------
230 the cgroup that brought it in -- this will happen on memory pressure).
232 But see :ref:`section 8.2 <cgroup-v1-memory-movable-charges>` when moving a
237 --------------------------------------
244 - memory.memsw.usage_in_bytes.
245 - memory.memsw.limit_in_bytes.
259 The global LRU(kswapd) can swap out arbitrary pages. Swap-out means
268 When a cgroup hits memory.memsw.limit_in_bytes, it's useless to do swap-out
269 in this cgroup. Then, swap-out will not be done by cgroup routine and file
275 -----------
282 cgroup. (See :ref:`10. OOM Control <cgroup-v1-memory-oom-control>` below.)
284 The reclaim algorithm has not been modified for cgroups, except that
285 pages that are selected for reclaiming come from the per-cgroup LRU
296 (See :ref:`oom_control <cgroup-v1-memory-oom-control>` section)
299 -----------
303 Page lock (PG_locked bit of page->flags)
304 mm->page_table_lock or split pte_lock
305 folio_memcg_lock (memcg->move_lock)
306 mapping->i_pages lock
307 lruvec->lru_lock.
309 Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by
310 lruvec->lru_lock; PG_lru bit of page->flags is cleared before
311 isolating a page from its LRU under lruvec->lru_lock.
313 .. _cgroup-v1-memory-kernel-extension:
316 -----------------------------------------------
324 it can be disabled system-wide by passing cgroup.memory=nokmem to the kernel
339 -----------------------------------------------
363 ----------------------
376 deployments where the total amount of memory per-cgroup is overcommitted.
378 box can still run out of non-reclaimable memory.
401 <cgroups-why-needed>` for the background information)::
403 # mount -t tmpfs none /sys/fs/cgroup
405 # mount -t cgroup none /sys/fs/cgroup/memory -o memory
427 We can write "-1" to reset the ``*.limit_in_bytes(unlimited)``.
441 availability of memory on the system. The user is required to re-read
463 Page-fault scalability is also important. At measuring parallel
464 page fault test, multi-process test may be better than multi-thread
470 .. _cgroup-v1-memory-test-troubleshoot:
473 -------------------
485 <cgroup-v1-memory-oom-control>` (below) and seeing what happens will be
488 .. _cgroup-v1-memory-test-task-migration:
491 ------------------
499 See :ref:`8. "Move charges at task migration" <cgroup-v1-memory-move-charges>`
502 ---------------------
505 <cgroup-v1-memory-test-troubleshoot>` and :ref:`4.2
506 <cgroup-v1-memory-test-task-migration>`, a cgroup might have some charge
521 ---------------
531 charged file caches. Some out-of-use page caches may keep charged until
535 -------------
539 * per-memory cgroup local status
547 pgpgin # of charging events to the memory cgroup. The charging
561 inactive_file # of bytes of file-backed memory and MADV_FREE anonymous
563 active_file # of bytes of file-backed memory on active LRU list.
608 --------------
619 -----------
631 ------------------
641 -------------
643 This is similar to numa_maps but operates on a per-memcg basis. This is
650 per-node page counts including "hierarchical_<counter>" which sums up all
681 If one of the ancestors goes over its limit, the reclaim algorithm reclaims
685 ---------------------------------------
709 Please note that soft limits is a best-effort feature; it comes with
716 -------------
735 .. _cgroup-v1-memory-move-charges:
744 cgroups to allow fine-grained policy adjustments without having to
753 -------------
765 <cgroup-v1-memory-movable-charges>` for details.
768 Charges are moved only when you move mm->owner, in other words,
783 .. _cgroup-v1-memory-movable-charges:
786 --------------------------------------
793 +---+--------------------------------------------------------------------------+
798 +---+--------------------------------------------------------------------------+
807 +---+--------------------------------------------------------------------------+
810 --------
812 - All of moving charge operations are done under cgroup_mutex. It's not good
824 - create an eventfd using eventfd(2);
825 - open memory.usage_in_bytes or memory.memsw.usage_in_bytes;
826 - write string like "<event_fd> <fd of memory.usage_in_bytes> <threshold>" to
832 It's applicable for root and non-root cgroup.
834 .. _cgroup-v1-memory-oom-control:
847 - create an eventfd using eventfd(2)
848 - open memory.oom_control file
849 - write string like "<event_fd> <fd of memory.oom_control>" to
855 You can disable the OOM-killer by writing "1" to memory.oom_control file, as:
859 If OOM-killer is disabled, tasks under cgroup will hang/sleep
860 in memory cgroup's OOM-waitqueue when they request accountable memory.
876 - oom_kill_disable 0 or 1
877 (if 1, oom-killer is disabled)
878 - under_oom 0 or 1
880 - oom_kill integer counter
902 resources that can be easily reconstructed or re-read from a disk.
905 about to out of memory (OOM) or even the in-kernel OOM killer is on its
911 events are not pass-through. For example, you have three cgroups: A->B->C. Now
921 - "default": this is the default behavior specified above. This mode is the
925 - "hierarchy": events always propagate up to the root, similar to the default
930 - "local": events are pass-through, i.e. they only receive notifications when
939 specified by a comma-delimited string, i.e. "low,hierarchy" specifies
940 hierarchical, pass-through, notification for all ancestor memcgs. Notification
941 that is the default, non pass-through behavior, does not specify a mode.
942 "medium,local" specifies pass-through notification for the medium level.
947 - create an eventfd using eventfd(2);
948 - open memory.pressure_level;
949 - write string as "<event_fd> <fd of memory.pressure_level> <level[,mode]>"
971 (Expect a bunch of notifications, and eventually, the oom-killer will
977 1. Make per-cgroup scanner reclaim not-shared pages first
978 2. Teach controller to account for shared-pages
1009 https://lore.kernel.org/r/20070819094658.654.84837.sendpatchset@balbir-laptop
1012 https://lore.kernel.org/r/20070817084228.26003.12568.sendpatchset@balbir-laptop