Lines Matching +full:fails +full:- +full:without +full:- +full:test +full:- +full:cd
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
36 d. A CD/DVD burner could control the amount of memory used by the
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>`)
162 -----------
170 ---------------
172 .. code-block::
175 +--------------------+
178 +--------------------+
181 +---------------+ | +---------------+
184 +---------------+ | +---------------+
186 + --------------+
188 +---------------+ +------+--------+
189 | page +----------> page_cgroup|
191 +---------------+ +---------------+
206 If everything goes well, a page meta-data-structure called page_cgroup is
208 (*) page_cgroup structure is allocated at boot/memory-hotplug time.
211 ------------------------
226 A swapped-in page is accounted after adding into swapcache.
228 Note: The kernel does swapin-readahead and reads multiple swaps at once.
234 Note: we just account pages-on-LRU because our purpose is to control amount
235 of used pages; not-on-LRU pages tend to be out-of-control from VM view.
238 --------------------------
244 the cgroup that brought it in -- this will happen on memory pressure).
246 But see :ref:`section 8.2 <cgroup-v1-memory-movable-charges>` when moving a
251 --------------------------------------
258 - memory.memsw.usage_in_bytes.
259 - memory.memsw.limit_in_bytes.
273 The global LRU(kswapd) can swap out arbitrary pages. Swap-out means
275 memory+swap. In other words, when we want to limit the usage of swap without
282 When a cgroup hits memory.memsw.limit_in_bytes, it's useless to do swap-out
283 in this cgroup. Then, swap-out will not be done by cgroup routine and file
289 -----------
296 cgroup. (See :ref:`10. OOM Control <cgroup-v1-memory-oom-control>` below.)
299 pages that are selected for reclaiming come from the per-cgroup LRU
310 (See :ref:`oom_control <cgroup-v1-memory-oom-control>` section)
313 -----------
318 mm->page_table_lock or split pte_lock
319 folio_memcg_lock (memcg->move_lock)
320 mapping->i_pages lock
321 lruvec->lru_lock.
323 Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by
324 lruvec->lru_lock; the folio LRU flag is cleared before
325 isolating a page from its LRU under lruvec->lru_lock.
327 .. _cgroup-v1-memory-kernel-extension:
330 -----------------------------------------------
338 it can be disabled system-wide by passing cgroup.memory=nokmem to the kernel
353 -----------------------------------------------
365 belong to the same memcg. This only fails to hold when a task is migrated to a
377 ----------------------
390 deployments where the total amount of memory per-cgroup is overcommitted.
392 box can still run out of non-reclaimable memory.
415 <cgroups-why-needed>` for the background information)::
417 # mount -t tmpfs none /sys/fs/cgroup
419 # mount -t cgroup none /sys/fs/cgroup/memory -o memory
441 We can write "-1" to reset the ``*.limit_in_bytes(unlimited)``.
455 availability of memory on the system. The user is required to re-read
473 Performance test is also important. To see pure memory controller's overhead,
477 Page-fault scalability is also important. At measuring parallel
478 page fault test, multi-process test may be better than multi-thread
479 test because it has noise of shared objects/status.
482 Trying usual test under memory controller is always helpful.
484 .. _cgroup-v1-memory-test-troubleshoot:
487 -------------------
499 <cgroup-v1-memory-oom-control>` (below) and seeing what happens will be
502 .. _cgroup-v1-memory-test-task-migration:
505 ------------------
513 See :ref:`8. "Move charges at task migration" <cgroup-v1-memory-move-charges>`
516 ---------------------
519 <cgroup-v1-memory-test-troubleshoot>` and :ref:`4.2
520 <cgroup-v1-memory-test-task-migration>`, a cgroup might have some charge
535 ---------------
545 charged file caches. Some out-of-use page caches may keep charged until
549 -------------
553 * per-memory cgroup local status
576 inactive_file # of bytes of file-backed memory and MADV_FREE anonymous
578 active_file # of bytes of file-backed memory on active LRU list.
623 --------------
634 -----------
646 ------------------
656 -------------
658 This is similar to numa_maps but operates on a per-memcg basis. This is
665 per-node page counts including "hierarchical_<counter>" which sums up all
700 ---------------------------------------
726 Please note that soft limits is a best-effort feature; it comes with
733 -------------
752 .. _cgroup-v1-memory-move-charges:
761 cgroups to allow fine-grained policy adjustments without having to
770 -------------
782 <cgroup-v1-memory-movable-charges>` for details.
785 Charges are moved only when you move mm->owner, in other words,
800 .. _cgroup-v1-memory-movable-charges:
803 --------------------------------------
810 +---+--------------------------------------------------------------------------+
815 +---+--------------------------------------------------------------------------+
824 +---+--------------------------------------------------------------------------+
827 --------
829 - All of moving charge operations are done under cgroup_mutex. It's not good
841 - create an eventfd using eventfd(2);
842 - open memory.usage_in_bytes or memory.memsw.usage_in_bytes;
843 - write string like "<event_fd> <fd of memory.usage_in_bytes> <threshold>" to
849 It's applicable for root and non-root cgroup.
851 .. _cgroup-v1-memory-oom-control:
866 - create an eventfd using eventfd(2)
867 - open memory.oom_control file
868 - write string like "<event_fd> <fd of memory.oom_control>" to
874 You can disable the OOM-killer by writing "1" to memory.oom_control file, as:
878 If OOM-killer is disabled, tasks under cgroup will hang/sleep
879 in memory cgroup's OOM-waitqueue when they request accountable memory.
895 - oom_kill_disable 0 or 1
896 (if 1, oom-killer is disabled)
897 - under_oom 0 or 1
899 - oom_kill integer counter
923 resources that can be easily reconstructed or re-read from a disk.
926 about to out of memory (OOM) or even the in-kernel OOM killer is on its
932 events are not pass-through. For example, you have three cgroups: A->B->C. Now
942 - "default": this is the default behavior specified above. This mode is the
946 - "hierarchy": events always propagate up to the root, similar to the default
951 - "local": events are pass-through, i.e. they only receive notifications when
960 specified by a comma-delimited string, i.e. "low,hierarchy" specifies
961 hierarchical, pass-through, notification for all ancestor memcgs. Notification
962 that is the default, non pass-through behavior, does not specify a mode.
963 "medium,local" specifies pass-through notification for the medium level.
968 - create an eventfd using eventfd(2);
969 - open memory.pressure_level;
970 - write string as "<event_fd> <fd of memory.pressure_level> <level[,mode]>"
977 Test:
983 # cd /sys/fs/cgroup/memory/
985 # cd foo
992 (Expect a bunch of notifications, and eventually, the oom-killer will
998 1. Make per-cgroup scanner reclaim not-shared pages first
999 2. Teach controller to account for shared-pages
1025 8. Singh, Balbir. RSS controller v2 test results (lmbench),
1029 10. Singh, Balbir. Memory controller v6 test results,
1030 https://lore.kernel.org/r/20070819094658.654.84837.sendpatchset@balbir-laptop
1033 https://lore.kernel.org/r/20070817084228.26003.12568.sendpatchset@balbir-laptop