summaryrefslogtreecommitdiffstats
path: root/Documentation/admin-guide/mm/ksm.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/admin-guide/mm/ksm.rst')
-rw-r--r--Documentation/admin-guide/mm/ksm.rst11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
index 776f244bda..e59231ac6b 100644
--- a/Documentation/admin-guide/mm/ksm.rst
+++ b/Documentation/admin-guide/mm/ksm.rst
@@ -155,6 +155,15 @@ stable_node_chains_prune_millisecs
scan. It's a noop if not a single KSM page hit the
``max_page_sharing`` yet.
+smart_scan
+ Historically KSM checked every candidate page for each scan. It did
+ not take into account historic information. When smart scan is
+ enabled, pages that have previously not been de-duplicated get
+ skipped. How often these pages are skipped depends on how often
+ de-duplication has already been tried and failed. By default this
+ optimization is enabled. The ``pages_skipped`` metric shows how
+ effective the setting is.
+
The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``:
general_profit
@@ -169,6 +178,8 @@ pages_unshared
how many pages unique but repeatedly checked for merging
pages_volatile
how many pages changing too fast to be placed in a tree
+pages_skipped
+ how many pages did the "smart" page scanning algorithm skip
full_scans
how many times all mergeable areas have been scanned
stable_node_chains