Commit af936a16 authored by Lee Schermerhorn's avatar Lee Schermerhorn Committed by Linus Torvalds
Browse files

vmscan: unevictable LRU scan sysctl 



This patch adds a function to scan individual or all zones' unevictable
lists and move any pages that have become evictable onto the respective
zone's inactive list, where shrink_inactive_list() will deal with them.

Adds sysctl to scan all nodes, and per node attributes to individual
nodes' zones.

Kosaki: If evictable page found in unevictable lru when write
/proc/sys/vm/scan_unevictable_pages, print filename and file offset of
these pages.

[akpm@linux-foundation.org: fix one CONFIG_MMU=n build error]
[kosaki.motohiro@jp.fujitsu.com: adapt vmscan-unevictable-lru-scan-sysctl.patch to new sysfs API]
Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 64d6519d

drivers/base/node.c

+5 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/nodemask.h>

#include <linux/cpu.h>

#include <linux/device.h>

#include <linux/swap.h>



static struct sysdev_class node_class = {

	.name = "node",
@@ -191,6 +192,8 @@ int register_node(struct node *node, int num, struct node *parent) 
		sysdev_create_file(&node->sysdev, &attr_meminfo);

		sysdev_create_file(&node->sysdev, &attr_numastat);

		sysdev_create_file(&node->sysdev, &attr_distance);



		scan_unevictable_register_node(node);

	}

	return error;

}
@@ -210,6 +213,8 @@ void unregister_node(struct node *node) 
	sysdev_remove_file(&node->sysdev, &attr_numastat);

	sysdev_remove_file(&node->sysdev, &attr_distance);



	scan_unevictable_unregister_node(node);



	sysdev_unregister(&node->sysdev);

}

include/linux/rmap.h

+3 −0
Original line number Diff line number Diff line
@@ -75,6 +75,9 @@ void anon_vma_unlink(struct vm_area_struct *); 
void anon_vma_link(struct vm_area_struct *);

void __anon_vma_link(struct vm_area_struct *);



extern struct anon_vma *page_lock_anon_vma(struct page *page);

extern void page_unlock_anon_vma(struct anon_vma *anon_vma);



/*

 * rmap interfaces called when adding or removing pte of page

 */

include/linux/swap.h

+15 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/list.h>

#include <linux/memcontrol.h>

#include <linux/sched.h>

#include <linux/node.h>



#include <asm/atomic.h>

#include <asm/page.h>
@@ -235,15 +236,29 @@ static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order) 
#ifdef CONFIG_UNEVICTABLE_LRU

extern int page_evictable(struct page *page, struct vm_area_struct *vma);

extern void scan_mapping_unevictable_pages(struct address_space *);



extern unsigned long scan_unevictable_pages;

extern int scan_unevictable_handler(struct ctl_table *, int, struct file *,

					void __user *, size_t *, loff_t *);

extern int scan_unevictable_register_node(struct node *node);

extern void scan_unevictable_unregister_node(struct node *node);

#else

static inline int page_evictable(struct page *page,

						struct vm_area_struct *vma)

{

	return 1;

}



static inline void scan_mapping_unevictable_pages(struct address_space *mapping)

{

}



static inline int scan_unevictable_register_node(struct node *node)

{

	return 0;

}



static inline void scan_unevictable_unregister_node(struct node *node) { }

#endif



extern int kswapd_run(int nid);

kernel/sysctl.c

+10 −0
Original line number Diff line number Diff line
@@ -833,6 +833,16 @@ static struct ctl_table kern_table[] = { 
		.proc_handler   = &proc_dointvec,

	},

#endif

#ifdef CONFIG_UNEVICTABLE_LRU

	{

		.ctl_name	= CTL_UNNUMBERED,

		.procname	= "scan_unevictable_pages",

		.data		= &scan_unevictable_pages,

		.maxlen		= sizeof(scan_unevictable_pages),

		.mode		= 0644,

		.proc_handler	= &scan_unevictable_handler,

	},

#endif

/*

 * NOTE: do not add new entries to this table unless you have read

 * Documentation/sysctl/ctl_unnumbered.txt

mm/rmap.c

+2 −2
Original line number Diff line number Diff line
@@ -181,7 +181,7 @@ void __init anon_vma_init(void) 
 * Getting a lock on a stable anon_vma from a page off the LRU is

 * tricky: page_lock_anon_vma rely on RCU to guard against the races.

 */

static struct anon_vma *page_lock_anon_vma(struct page *page)

struct anon_vma *page_lock_anon_vma(struct page *page)

{

	struct anon_vma *anon_vma;

	unsigned long anon_mapping;
@@ -201,7 +201,7 @@ out: 
	return NULL;

}



static void page_unlock_anon_vma(struct anon_vma *anon_vma)

void page_unlock_anon_vma(struct anon_vma *anon_vma)

{

	spin_unlock(&anon_vma->lock);

	rcu_read_unlock();

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