[PATCH v5 2/4] mm/page_reporting: Export reporting order as module parameter
From: Gavin Shan <hidden>
Date: 2021-06-25 02:21:21
Also in:
lkml
Subsystem:
documentation, memory management, memory management - page allocator, the rest · Maintainers:
Jonathan Corbet, Andrew Morton, Vlastimil Babka, Linus Torvalds
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 at
the beginning, meaning the page reporting is disabled. It will be
restored to @pageblock_order when page reporting device is registered.
It's also exported so that the page reporting order can be adjusted
at runtime.
Suggested-by: David Hildenbrand <redacted>
Signed-off-by: Gavin Shan <redacted>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
---
v5: Restore @page_reporting_order to @pageblock_order when device
is registered
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
mm/page_reporting.c | 13 +++++++++++--
mm/page_reporting.h | 5 ++---
3 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index cb89dbdedc46..566c4b9af3cd 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/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
diff --git a/mm/page_reporting.c b/mm/page_reporting.c
index df9c5054e1b4..133222234f25 100644
--- a/mm/page_reporting.c
+++ b/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_reporting_dev_info *prdev, /* 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_reporting_dev_info *prdev, 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))
@@ -324,6 +329,10 @@ int page_reporting_register(struct page_reporting_dev_info *prdev) goto err_out; } + /* Update the page reporting order with @pageblock_order */ + if (page_reporting_order > pageblock_order) + page_reporting_order = pageblock_order; + /* initialize state and work structures */ atomic_set(&prdev->state, PAGE_REPORTING_IDLE); INIT_DELAYED_WORK(&prdev->work, &page_reporting_process);
diff --git a/mm/page_reporting.h b/mm/page_reporting.h
index 2c385dd4ddbd..c51dbc228b94 100644
--- a/mm/page_reporting.h
+++ b/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_free(unsigned int order) 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 */
--
2.23.0