The patch titled
Subject: mm/page_reporting: export reporting order as module parameter
has been added to the -mm tree. Its filename is
mm-page_reporting-export-reporting-order-as-module-parameter.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_reporting-export-reporting-order-as-module-parameter.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_reporting-export-reporting-order-as-module-parameter.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Gavin Shan <gshan@xxxxxxxxxx>
Subject: mm/page_reporting: export reporting order as module parameter
The macro PAGE_REPORTING_MIN_ORDER is defined as the page reporting
threshold. It can't be adjusted at runtime.
This introduces a variable (@page_reporting_order) to replace the marcro
(PAGE_REPORTING_MIN_ORDER). MAX_ORDER is assigned to it initially,
meaning the page reporting is disabled. It will be specified by driver if
valid one is provided. Otherwise, it will fall back to @pageblock_order.
It's also exported so that the page reporting order can be adjusted at
runtime.
Link: https://lkml.kernel.org/r/20210625014710.42954-3-gshan@xxxxxxxxxx
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Alexander Duyck <alexanderduyck@xxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
mm/page_reporting.c | 9 +++++++--
mm/page_reporting.h | 5 ++---
3 files changed, 15 insertions(+), 5 deletions(-)
--- a/Documentation/admin-guide/kernel-parameters.txt~mm-page_reporting-export-reporting-order-as-module-parameter
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -3566,6 +3566,12 @@
off: turn off poisoning (default)
on: turn on poisoning
+ page_reporting.page_reporting_order=
+ [KNL] Minimal page reporting order
+ Format: <integer>
+ Adjust the minimal page reporting order. The page
+ reporting is disabled when it exceeds (MAX_ORDER-1).
+
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
--- a/mm/page_reporting.c~mm-page_reporting-export-reporting-order-as-module-parameter
+++ a/mm/page_reporting.c
@@ -4,12 +4,17 @@
#include <linux/page_reporting.h>
#include <linux/gfp.h>
#include <linux/export.h>
+#include <linux/module.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include "page_reporting.h"
#include "internal.h"
+unsigned int page_reporting_order = MAX_ORDER;
+module_param(page_reporting_order, uint, 0644);
+MODULE_PARM_DESC(page_reporting_order, "Set page reporting order");
+
#define PAGE_REPORTING_DELAY (2 * HZ)
static struct page_reporting_dev_info __rcu *pr_dev_info __read_mostly;
@@ -229,7 +234,7 @@ page_reporting_process_zone(struct page_
/* Generate minimum watermark to be able to guarantee progress */
watermark = low_wmark_pages(zone) +
- (PAGE_REPORTING_CAPACITY << PAGE_REPORTING_MIN_ORDER);
+ (PAGE_REPORTING_CAPACITY << page_reporting_order);
/*
* Cancel request if insufficient free memory or if we failed
@@ -239,7 +244,7 @@ page_reporting_process_zone(struct page_
return err;
/* Process each free list starting from lowest order/mt */
- for (order = PAGE_REPORTING_MIN_ORDER; order < MAX_ORDER; order++) {
+ for (order = page_reporting_order; order < MAX_ORDER; order++) {
for (mt = 0; mt < MIGRATE_TYPES; mt++) {
/* We do not pull pages from the isolate free list */
if (is_migrate_isolate(mt))
--- a/mm/page_reporting.h~mm-page_reporting-export-reporting-order-as-module-parameter
+++ a/mm/page_reporting.h
@@ -10,10 +10,9 @@
#include <linux/pgtable.h>
#include <linux/scatterlist.h>
-#define PAGE_REPORTING_MIN_ORDER pageblock_order
-
#ifdef CONFIG_PAGE_REPORTING
DECLARE_STATIC_KEY_FALSE(page_reporting_enabled);
+extern unsigned int page_reporting_order;
void __page_reporting_notify(void);
static inline bool page_reported(struct page *page)
@@ -38,7 +37,7 @@ static inline void page_reporting_notify
return;
/* Determine if we have crossed reporting threshold */
- if (order < PAGE_REPORTING_MIN_ORDER)
+ if (order < page_reporting_order)
return;
/* This will add a few cycles, but should be called infrequently */
_
Patches currently in -mm which might be from gshan@xxxxxxxxxx are
mm-page_reporting-fix-code-style-in-__page_reporting_request.patch
mm-page_reporting-export-reporting-order-as-module-parameter.patch
mm-page_reporting-allow-driver-to-specify-reporting-order.patch
virtio_balloon-specify-page-reporting-order-if-needed.patch
