diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/blockdev/zram.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/memory.rst | 82 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 5 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 17 | ||||
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 35 |
5 files changed, 60 insertions, 81 deletions
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 678d70d6e1c3..714a5171bfc0 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -47,6 +47,8 @@ The list of possible return codes: -ENOMEM zram was not able to allocate enough memory to fulfil your needs. -EINVAL invalid input has been provided. +-EAGAIN re-try operation later (e.g. when attempting to run recompress + and writeback simultaneously). ======== ============================================================= If you use 'echo', the returned value is set by the 'echo' utility, diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 270501db9f4e..286d16fc22eb 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -90,9 +90,7 @@ Brief summary of control files. used. memory.swappiness set/show swappiness parameter of vmscan (See sysctl's vm.swappiness) - memory.move_charge_at_immigrate set/show controls of moving charges - This knob is deprecated and shouldn't be - used. + memory.move_charge_at_immigrate This knob is deprecated. memory.oom_control set/show oom controls. This knob is deprecated and shouldn't be used. @@ -243,10 +241,6 @@ behind this approach is that a cgroup that aggressively uses a shared page will eventually get charged for it (once it is uncharged from the cgroup that brought it in -- this will happen on memory pressure). -But see :ref:`section 8.2 <cgroup-v1-memory-movable-charges>` when moving a -task to another cgroup, its pages may be recharged to the new cgroup, if -move_charge_at_immigrate has been chosen. - 2.4 Swap Extension -------------------------------------- @@ -756,78 +750,8 @@ If we want to change this to 1G, we can at any time use:: THIS IS DEPRECATED! -It's expensive and unreliable! It's better practice to launch workload -tasks directly from inside their target cgroup. Use dedicated workload -cgroups to allow fine-grained policy adjustments without having to -move physical pages between control domains. - -Users can move charges associated with a task along with task migration, that -is, uncharge task's pages from the old cgroup and charge them to the new cgroup. -This feature is not supported in !CONFIG_MMU environments because of lack of -page tables. - -8.1 Interface -------------- - -This feature is disabled by default. It can be enabled (and disabled again) by -writing to memory.move_charge_at_immigrate of the destination cgroup. - -If you want to enable it:: - - # echo (some positive value) > memory.move_charge_at_immigrate - -.. note:: - Each bits of move_charge_at_immigrate has its own meaning about what type - of charges should be moved. See :ref:`section 8.2 - <cgroup-v1-memory-movable-charges>` for details. - -.. note:: - Charges are moved only when you move mm->owner, in other words, - a leader of a thread group. - -.. note:: - If we cannot find enough space for the task in the destination cgroup, we - try to make space by reclaiming memory. Task migration may fail if we - cannot make enough space. - -.. note:: - It can take several seconds if you move charges much. - -And if you want disable it again:: - - # echo 0 > memory.move_charge_at_immigrate - -.. _cgroup-v1-memory-movable-charges: - -8.2 Type of charges which can be moved --------------------------------------- - -Each bit in move_charge_at_immigrate has its own meaning about what type of -charges should be moved. But in any case, it must be noted that an account of -a page or a swap can be moved only when it is charged to the task's current -(old) memory cgroup. - -+---+--------------------------------------------------------------------------+ -|bit| what type of charges would be moved ? | -+===+==========================================================================+ -| 0 | A charge of an anonymous page (or swap of it) used by the target task. | -| | You must enable Swap Extension (see 2.4) to enable move of swap charges. | -+---+--------------------------------------------------------------------------+ -| 1 | A charge of file pages (normal file, tmpfs file (e.g. ipc shared memory) | -| | and swaps of tmpfs file) mmapped by the target task. Unlike the case of | -| | anonymous pages, file pages (and swaps) in the range mmapped by the task | -| | will be moved even if the task hasn't done page fault, i.e. they might | -| | not be the task's "RSS", but other task's "RSS" that maps the same file. | -| | The mapcount of the page is ignored (the page can be moved independent | -| | of the mapcount). You must enable Swap Extension (see 2.4) to | -| | enable move of swap charges. | -+---+--------------------------------------------------------------------------+ - -8.3 TODO --------- - -- All of moving charge operations are done under cgroup_mutex. It's not good - behavior to hold the mutex too long, so we may need some trick. +Reading memory.move_charge_at_immigrate will always return 0 and writing +to it will always return -EINVAL. 9. Memory thresholds ==================== diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 2cb58daf3089..315ede811c9d 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1655,6 +1655,11 @@ The following nested keys are defined. pgdemote_khugepaged Number of pages demoted by khugepaged. + hugetlb + Amount of memory used by hugetlb pages. This metric only shows + up if hugetlb usage is accounted for in memory.current (i.e. + cgroup is mounted with the memory_hugetlb_accounting option). + memory.numa_stat A read-only nested-keyed file which exists on non-root cgroups. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9cd9cd06538b..a4736ee87b1a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6711,6 +6711,16 @@ Force threading of all interrupt handlers except those marked explicitly IRQF_NO_THREAD. + thp_shmem= [KNL] + Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy> + Control the default policy of each hugepage size for the + internal shmem mount. <policy> is one of policies available + for the shmem mount ("always", "inherit", "never", "within_size", + and "advise"). + It can be used multiple times for multiple shmem THP sizes. + See Documentation/admin-guide/mm/transhuge.rst for more + details. + topology= [S390,EARLY] Format: {off | on} Specify if the kernel should make use of the cpu @@ -6952,6 +6962,13 @@ See Documentation/admin-guide/mm/transhuge.rst for more details. + transparent_hugepage_shmem= [KNL] + Format: [always|within_size|advise|never|deny|force] + Can be used to control the hugepage allocation policy for + the internal shmem mount. + See Documentation/admin-guide/mm/transhuge.rst + for more details. + trusted.source= [KEYS] Format: <string> This parameter identifies the trust source as a backend diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index a1bb495eab59..5034915f4e8e 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -326,6 +326,29 @@ PMD_ORDER THP policy will be overridden. If the policy for PMD_ORDER is not defined within a valid ``thp_anon``, its policy will default to ``never``. +Similarly to ``transparent_hugepage``, you can control the hugepage +allocation policy for the internal shmem mount by using the kernel parameter +``transparent_hugepage_shmem=<policy>``, where ``<policy>`` is one of the +seven valid policies for shmem (``always``, ``within_size``, ``advise``, +``never``, ``deny``, and ``force``). + +In the same manner as ``thp_anon`` controls each supported anonymous THP +size, ``thp_shmem`` controls each supported shmem THP size. ``thp_shmem`` +has the same format as ``thp_anon``, but also supports the policy +``within_size``. + +``thp_shmem=`` may be specified multiple times to configure all THP sizes +as required. If ``thp_shmem=`` is specified at least once, any shmem THP +sizes not explicitly configured on the command line are implicitly set to +``never``. + +``transparent_hugepage_shmem`` setting only affects the global toggle. If +``thp_shmem`` is not specified, PMD_ORDER hugepage will default to +``inherit``. However, if a valid ``thp_shmem`` setting is provided by the +user, the PMD_ORDER hugepage policy will be overridden. If the policy for +PMD_ORDER is not defined within a valid ``thp_shmem``, its policy will +default to ``never``. + Hugepages in tmpfs/shmem ======================== @@ -530,10 +553,18 @@ anon_fault_fallback_charge instead falls back to using huge pages with lower orders or small pages even though the allocation was successful. -swpout - is incremented every time a huge page is swapped out in one +zswpout + is incremented every time a huge page is swapped out to zswap in one piece without splitting. +swpin + is incremented every time a huge page is swapped in from a non-zswap + swap device in one piece. + +swpout + is incremented every time a huge page is swapped out to a non-zswap + swap device in one piece without splitting. + swpout_fallback is incremented if a huge page has to be split before swapout. Usually because failed to allocate some continuous swap space |