[PATCH v3 2/2] mm/ksm: fix advisor_min_pages_to_scan description

[Jinjiang Tu <tujinjiang@huawei.com>]

Both Documentation/admin-guide/mm/ksm.rst and the comment next to the
variable definition in mm/ksm.c describe advisor_min_pages_to_scan as a
lower limit of the pages_to_scan parameter, but that is not how the
scan-time advisor actually uses it. commit 4e5fa4f5eff6 ("mm/ksm: add ksm
advisor") only uses it to initialize ksm_thread_pages_to_scan when the
scan-time advisor is enabled.

ksm_thread_pages_to_scan is adjusted by scan_time_advisor() after a full
scan finishes. ksm_thread_pages_to_scan could be increased or decreased
depend on the real scan time is longer or shorter than the target scan
time. The min value of ksm_thread_pages_to_scan is only limited by
KSM_ADVISOR_MIN_CPU, so ksm_thread_pages_to_scan could be smaller than
ksm_advisor_min_pages_to_scan.

The semantics of advisor_min_pages_to_scan was updated in the v2 patchset
[1], but the documentation wasn't updated.

Update the documentation and comment to match the semantics of
advisor_min_pages_to_scan.

Link: https://lore.kernel.org/linux-mm/20231028000945.2428830-2-shr@devkernel.io/ [1]
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
---
 Documentation/admin-guide/mm/ksm.rst | 4 ++--
 mm/ksm.c                             | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
index c9f533b10f6f..c329ca747b8c 100644
--- a/Documentation/admin-guide/mm/ksm.rst
+++ b/Documentation/admin-guide/mm/ksm.rst
@@ -183,8 +183,8 @@ advisor_target_scan_time
         pages. The default value is 200 seconds.
 
 advisor_min_pages_to_scan
-        specifies the lower limit of the ``pages_to_scan`` parameter of the
-        scan time advisor. The default is 500.
+        specifies the initial value of the ``pages_to_scan`` parameter of
+        the scan time advisor. The default is 500.
 
 advisor_max_pages_to_scan
         specifies the upper limit of the ``pages_to_scan`` parameter of the
diff --git a/mm/ksm.c b/mm/ksm.c
index 7d5b76478f0b..4a6cf8cf5d60 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -342,7 +342,7 @@ static enum ksm_advisor_type ksm_advisor;
  * Only called through the sysfs control interface:
  */
 
-/* At least scan this many pages per batch. */
+/* Initial number of pages to scan per batch. */
 static unsigned long ksm_advisor_min_pages_to_scan = 500;
 
 static void set_advisor_defaults(void)
-- 
2.43.0