Commit f58780a8 authored by Gavin Shan's avatar Gavin Shan Committed by Linus Torvalds
Browse files

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@redhat.com


Signed-off-by: default avatarGavin Shan <gshan@redhat.com>
Suggested-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarAlexander Duyck <alexanderduyck@fb.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5631de54

Documentation/admin-guide/kernel-parameters.txt

+6 −0
Original line number Diff line number Diff line
@@ -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

mm/page_reporting.c

+7 −2
Original line number Diff line number Diff line
@@ -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))

mm/page_reporting.h

+2 −3
Original line number Diff line number Diff line
@@ -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 */