commit 5ef64cc8987a ("mm: allow a controlled amount of unfairness in the page lock")
introduced a new systctl but no accompanying documentation.
Add a simple entry to the documentation.
Signed-off-by: Joel Savitz <jsavitz@xxxxxxxxxx>
---
Documentation/admin-guide/sysctl/vm.rst | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index f4804ce37c58..747e325ebcd0 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -62,6 +62,7 @@ Currently, these files are in /proc/sys/vm:
- overcommit_memory
- overcommit_ratio
- page-cluster
+- page_lock_unfairness
- panic_on_oom
- percpu_pagelist_high_fraction
- stat_interval
@@ -754,6 +755,14 @@ extra faults and I/O delays for following faults if they would have been part of
that consecutive pages readahead would have brought in.
+page_lock_unfairness
+====================
+
+This value determines the number of times that the page lock can be
+stolen from under a waiter. After the lock is stolen the number of times
+specified in this file (default is 5), the "fair lock handoff" semantics
+will apply, and the waiter will only be awakened if the lock can be taken.
+
panic_on_oom
============
--
2.27.0
