diff options
| author | Stefan Roesch <shr@devkernel.io> | 2023-04-17 22:13:41 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-21 14:52:03 -0700 |
| commit | d21077fbc2fc987c2e593c34dc3b4d84e546dc9f (patch) | |
| tree | 1a56ca5e4613bc2a491ddbcb3d62c7064c97f276 /Documentation/admin-guide/mm/ksm.rst | |
| parent | d7597f59d1d33e9efbffa7060deb9ee5bd119e62 (diff) | |
mm: add new KSM process and sysfs knobs
This adds the general_profit KSM sysfs knob and the process profit metric
knobs to ksm_stat.
1) expose general_profit metric
The documentation mentions a general profit metric, however this
metric is not calculated. In addition the formula depends on the size
of internal structures, which makes it more difficult for an
administrator to make the calculation. Adding the metric for a better
user experience.
2) document general_profit sysfs knob
3) calculate ksm process profit metric
The ksm documentation mentions the process profit metric and how to
calculate it. This adds the calculation of the metric.
4) mm: expose ksm process profit metric in ksm_stat
This exposes the ksm process profit metric in /proc/<pid>/ksm_stat.
The documentation mentions the formula for the ksm process profit
metric, however it does not calculate it. In addition the formula
depends on the size of internal structures. So it makes sense to
expose it.
5) document new procfs ksm knobs
Link: https://lkml.kernel.org/r/20230418051342.1919757-3-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/admin-guide/mm/ksm.rst')
| -rw-r--r-- | Documentation/admin-guide/mm/ksm.rst | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst index eed51a910c94..551083a396fb 100644 --- a/Documentation/admin-guide/mm/ksm.rst +++ b/Documentation/admin-guide/mm/ksm.rst @@ -157,6 +157,8 @@ stable_node_chains_prune_millisecs The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``: +general_profit + how effective is KSM. The calculation is explained below. pages_shared how many shared pages are being used pages_sharing @@ -207,7 +209,8 @@ several times, which are unprofitable memory consumed. ksm_rmap_items * sizeof(rmap_item). where ksm_merging_pages is shown under the directory ``/proc/<pid>/``, - and ksm_rmap_items is shown in ``/proc/<pid>/ksm_stat``. + and ksm_rmap_items is shown in ``/proc/<pid>/ksm_stat``. The process profit + is also shown in ``/proc/<pid>/ksm_stat`` as ksm_process_profit. From the perspective of application, a high ratio of ``ksm_rmap_items`` to ``ksm_merging_pages`` means a bad madvise-applied policy, so developers or |