Weekly Edition
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O(1) vm (rmap15) for 2.4.20-rc2-ac1
Here it is. Compiles, boots, couple of LTP runs with dd if=/dev/zero
of=zzz bs=256M count=1 looping in background
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet v2.4.20-rc2-ac1 -> 1.793
# include/linux/mmzone.h 1.10 -> 1.11
# include/linux/list.h 1.9 -> 1.10
# include/linux/pagemap.h 1.19 -> 1.20
# kernel/ksyms.c 1.65 -> 1.66
# include/linux/swap.h 1.36 -> 1.37
# include/linux/mm.h 1.40 -> 1.41
# mm/page_alloc.c 1.57 -> 1.58
# mm/rmap.c 1.1 -> 1.2
# mm/vmscan.c 1.63 -> 1.64
# fs/proc/proc_misc.c 1.19 -> 1.20
# mm/filemap.c 1.73 -> 1.74
# include/linux/brlock.h 1.4 -> 1.5
# include/linux/mm_inline.h 1.1 -> 1.2
# mm/swap.c 1.18 -> 1.19
# mm/shmem.c 1.46 -> 1.47
# mm/swap_state.c 1.19 -> 1.20
# fs/buffer.c 1.76 -> 1.77
# include/linux/module.h 1.12 -> 1.13
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/11/20 stingray@boxster.stingr.net 1.792
# 2.4.20-rc2-ac1
# --------------------------------------------
# 02/11/20 stingray@proxy.sgu.ru 1.793
# rmap15
# --------------------------------------------
#
diff -Nru a/fs/buffer.c b/fs/buffer.c
--- a/fs/buffer.c Wed Nov 20 17:19:24 2002
+++ b/fs/buffer.c Wed Nov 20 17:19:24 2002
@@ -2915,6 +2915,30 @@
}
}
+
+/*
+ * Do some IO post-processing here!!!
+ */
+void do_io_postprocessing(void)
+{
+ int i;
+ struct buffer_head *bh, *next;
+
+ spin_lock(&lru_list_lock);
+ bh = lru_list[BUF_LOCKED];
+ if (bh) {
+ for (i = nr_buffers_type[BUF_LOCKED]; i-- > 0; bh = next) {
+ next = bh->b_next_free;
+
+ if (!buffer_locked(bh))
+ __refile_buffer(bh);
+ else
+ break;
+ }
+ }
+ spin_unlock(&lru_list_lock);
+}
+
/*
* This is the kernel update daemon. It was used to live in userspace
* but since it's need to run safely we want it unkillable by mistake.
@@ -2966,6 +2990,7 @@
#ifdef DEBUG
printk(KERN_DEBUG "kupdate() activated...\n");
#endif
+ do_io_postprocessing();
sync_old_buffers();
run_task_queue(&tq_disk);
}
diff -Nru a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
--- a/fs/proc/proc_misc.c Wed Nov 20 17:19:24 2002
+++ b/fs/proc/proc_misc.c Wed Nov 20 17:19:24 2002
@@ -192,6 +192,7 @@
"SwapCached: %8lu kB\n"
"Active: %8u kB\n"
"Inact_dirty: %8u kB\n"
+ "Inact_laundry:%8u kB\n"
"Inact_clean: %8u kB\n"
"Inact_target: %8u kB\n"
"HighTotal: %8lu kB\n"
@@ -209,6 +210,7 @@
K(swapper_space.nrpages),
K(nr_active_pages),
K(nr_inactive_dirty_pages),
+ K(nr_inactive_laundry_pages),
K(nr_inactive_clean_pages),
K(inactive_target()),
K(i.totalhigh),
diff -Nru a/include/linux/brlock.h b/include/linux/brlock.h
--- a/include/linux/brlock.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/brlock.h Wed Nov 20 17:19:24 2002
@@ -37,6 +37,8 @@
BR_GLOBALIRQ_LOCK,
BR_NETPROTO_LOCK,
BR_LLC_LOCK,
+ BR_LRU_LOCK,
+
__BR_END
};
diff -Nru a/include/linux/list.h b/include/linux/list.h
--- a/include/linux/list.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/list.h Wed Nov 20 17:19:24 2002
@@ -137,8 +137,7 @@
return head->next == head;
}
-static inline void __list_splice(struct list_head *list,
- struct list_head *head)
+static inline void __list_splice(struct list_head *list, struct list_head *head)
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
diff -Nru a/include/linux/mm.h b/include/linux/mm.h
--- a/include/linux/mm.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/mm.h Wed Nov 20 17:19:24 2002
@@ -1,5 +1,23 @@
#ifndef _LINUX_MM_H
#define _LINUX_MM_H
+/*
+ * Copyright (c) 2002. All rights reserved.
+ *
+ * This software may be freely redistributed under the terms of the
+ * GNU General Public License.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Authors:
+ * Linus Torvalds
+ * Stephen Tweedie
+ * Andrea Arcangeli
+ * Rik van Riel
+ * Arjan van de Ven
+ * and others
+ */
#include <linux/sched.h>
#include <linux/errno.h>
@@ -168,7 +186,7 @@
unsigned long flags; /* atomic flags, some possibly
updated asynchronously */
struct list_head lru; /* Pageout list, eg. active_list;
- protected by pagemap_lru_lock !! */
+ protected by the lru lock !! */
unsigned char age; /* Page aging counter. */
struct pte_chain * pte_chain; /* Reverse pte mapping pointer.
* protected by PG_chainlock
@@ -279,7 +297,7 @@
*
* Note that the referenced bit, the page->lru list_head and the
* active, inactive_dirty and inactive_clean lists are protected by
- * the pagemap_lru_lock, and *NOT* by the usual PG_locked bit!
+ * the lru lock, and *NOT* by the usual PG_locked bit!
*
* PG_skip is used on sparc/sparc64 architectures to "skip" certain
* parts of the address space.
@@ -300,18 +318,19 @@
#define PG_referenced 2
#define PG_uptodate 3
#define PG_dirty 4
-#define PG_inactive_clean 5
-#define PG_active 6
+#define PG_active 5
#define PG_inactive_dirty 7
-#define PG_slab 8
-#define PG_skip 10
-#define PG_highmem 11
-#define PG_checked 12 /* kill me in 2.5.<early>. */
-#define PG_arch_1 13
-#define PG_reserved 14
-#define PG_launder 15 /* written out by VM pressure.. */
-#define PG_chainlock 16 /* lock bit for ->pte_chain */
-#define PG_lru 17
+#define PG_inactive_laundry 8
+#define PG_inactive_clean 9
+#define PG_slab 10
+#define PG_skip 11
+#define PG_highmem 12
+#define PG_checked 13 /* kill me in 2.5.<early>. */
+#define PG_arch_1 14
+#define PG_reserved 15
+#define PG_launder 16 /* written out by VM pressure.. */
+#define PG_chainlock 17 /* lock bit for ->pte_chain */
+#define PG_lru 18
/* Don't you dare to use high bits, they seem to be used for something else! */
@@ -429,11 +448,16 @@
#define PageClearSlab(page) clear_bit(PG_slab, &(page)->flags)
#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
-#define PageActive(page) test_bit(PG_active, &(page)->flags)
+#define PageActive(page) test_bit(PG_active, &(page)->flags)
#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
#define TestandSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags)
#define TestandClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags)
+
+
+#define PageInactiveLaundry(page) test_bit(PG_inactive_laundry, &(page)->flags)
+#define SetPageInactiveLaundry(page) set_bit(PG_inactive_laundry, &(page)->flags)
+#define ClearPageInactiveLaundry(page) clear_bit(PG_inactive_laundry, &(page)->flags)
#define PageInactiveDirty(page) test_bit(PG_inactive_dirty, &(page)->flags)
#define SetPageInactiveDirty(page) set_bit(PG_inactive_dirty, &(page)->flags)
diff -Nru a/include/linux/mm_inline.h b/include/linux/mm_inline.h
--- a/include/linux/mm_inline.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/mm_inline.h Wed Nov 20 17:19:24 2002
@@ -2,21 +2,77 @@
#define _LINUX_MM_INLINE_H
#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/brlock.h>
+
+
+/*
+ * Copyright (c) 2002. All rights reserved.
+ *
+ * This software may be freely redistributed under the terms of the
+ * GNU General Public License.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Authors:
+ * Linus Torvalds
+ * Stephen Tweedie
+ * Andrea Arcangeli
+ * Rik van Riel
+ * Arjan van de Ven
+ * and others
+ */
+
+GPL_HEADER()
+
+extern unsigned char active_age_bias;
/*
* These inline functions tend to need bits and pieces of all the
* other VM include files, meaning they cannot be defined inside
* one of the other VM include files.
+ *
+ */
+
+/**
+ * page_dirty - do we need to write the data out to disk
+ * @page: page to test
*
- * The include file mess really needs to be cleaned up...
+ * Returns true if the page contains data which needs to
+ * be written to disk. Doesn't test the page tables (yet?).
*/
+static inline int page_dirty(struct page *page)
+{
+ struct buffer_head *tmp, *bh;
+
+ if (PageDirty(page))
+ return 1;
+
+ if (page->mapping && !page->buffers)
+ return 0;
+
+ tmp = bh = page->buffers;
+
+ do {
+ if (tmp->b_state & ((1<<BH_Dirty) | (1<<BH_Lock)))
+ return 1;
+ tmp = tmp->b_this_page;
+ } while (tmp != bh);
-static inline void add_page_to_active_list(struct page * page)
+ return 0;
+}
+
+
+
+static inline void add_page_to_active_list(struct page * page, int age)
{
struct zone_struct * zone = page_zone(page);
DEBUG_LRU_PAGE(page);
SetPageActive(page);
- list_add(&page->lru, &zone->active_list);
+ list_add(&page->lru, &zone->active_list[age]);
+ page->age = age + active_age_bias;
zone->active_pages++;
nr_active_pages++;
}
@@ -31,6 +87,16 @@
nr_inactive_dirty_pages++;
}
+static inline void add_page_to_inactive_laundry_list(struct page * page)
+{
+ struct zone_struct * zone = page_zone(page);
+ DEBUG_LRU_PAGE(page);
+ SetPageInactiveLaundry(page);
+ list_add(&page->lru, &zone->inactive_laundry_list);
+ zone->inactive_laundry_pages++;
+ nr_inactive_laundry_pages++;
+}
+
static inline void add_page_to_inactive_clean_list(struct page * page)
{
struct zone_struct * zone = page_zone(page);
@@ -44,10 +110,14 @@
static inline void del_page_from_active_list(struct page * page)
{
struct zone_struct * zone = page_zone(page);
+ unsigned char age;
list_del(&page->lru);
ClearPageActive(page);
nr_active_pages--;
zone->active_pages--;
+ age = page->age - active_age_bias;
+ if (age<=MAX_AGE)
+ zone->active_count[age]--;
DEBUG_LRU_PAGE(page);
}
@@ -61,6 +131,16 @@
DEBUG_LRU_PAGE(page);
}
+static inline void del_page_from_inactive_laundry_list(struct page * page)
+{
+ struct zone_struct * zone = page_zone(page);
+ list_del(&page->lru);
+ ClearPageInactiveLaundry(page);
+ nr_inactive_laundry_pages--;
+ zone->inactive_laundry_pages--;
+ DEBUG_LRU_PAGE(page);
+}
+
static inline void del_page_from_inactive_clean_list(struct page * page)
{
struct zone_struct * zone = page_zone(page);
@@ -184,7 +264,7 @@
{
int inactive, target, inactive_base;
- inactive_base = zone->active_pages + zone->inactive_dirty_pages;
+ inactive_base = zone->active_pages + zone->inactive_dirty_pages;
inactive_base /= INACTIVE_FACTOR;
/* GCC should optimise this away completely. */
@@ -253,7 +333,12 @@
*/
static inline int inactive_high(struct zone_struct * zone)
{
- return inactive_limit(zone, VM_HIGH);
+ unsigned long active, inactive;
+ active = zone->active_pages + zone->free_pages;
+ inactive = zone->inactive_dirty_pages + zone->inactive_clean_pages + zone->inactive_laundry_pages;
+ if (inactive * 5 > (active+inactive))
+ return -1;
+ return 1;
}
/*
@@ -264,11 +349,31 @@
int target;
target = nr_active_pages + nr_inactive_dirty_pages
- + nr_inactive_clean_pages;
+ + nr_inactive_clean_pages + nr_inactive_laundry_pages;
target /= INACTIVE_FACTOR;
return target;
+}
+
+static inline void lru_lock(struct zone_struct *zone)
+{
+ if (zone) {
+ br_read_lock(BR_LRU_LOCK);
+ spin_lock(&zone->lru_lock);
+ } else {
+ br_write_lock(BR_LRU_LOCK);
+ }
+}
+
+static inline void lru_unlock(struct zone_struct *zone)
+{
+ if (zone) {
+ spin_unlock(&zone->lru_lock);
+ br_read_unlock(BR_LRU_LOCK);
+ } else {
+ br_write_unlock(BR_LRU_LOCK);
+ }
}
#endif /* _LINUX_MM_INLINE_H */
diff -Nru a/include/linux/mmzone.h b/include/linux/mmzone.h
--- a/include/linux/mmzone.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/mmzone.h Wed Nov 20 17:19:24 2002
@@ -13,11 +13,7 @@
* Free memory management - zoned buddy allocator.
*/
-#ifndef CONFIG_FORCE_MAX_ZONEORDER
#define MAX_ORDER 10
-#else
-#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
-#endif
typedef struct free_area_struct {
struct list_head free_list;
@@ -29,6 +25,9 @@
#define MAX_CHUNKS_PER_NODE 8
+#define MAX_AGE 15
+#define INITIAL_AGE 3
+
#define MAX_PER_CPU_PAGES 512
typedef struct per_cpu_pages_s {
int nr_pages, max_nr_pages;
@@ -52,17 +51,22 @@
unsigned long free_pages;
unsigned long active_pages;
unsigned long inactive_dirty_pages;
+ unsigned long inactive_laundry_pages;
unsigned long inactive_clean_pages;
unsigned long pages_min, pages_low, pages_high, pages_plenty;
int need_balance;
+ int need_scan;
+ int active_count[MAX_AGE+1];
/*
* free areas of different sizes
*/
- struct list_head active_list;
+ struct list_head active_list[MAX_AGE+1];
struct list_head inactive_dirty_list;
+ struct list_head inactive_laundry_list;
struct list_head inactive_clean_list;
free_area_t free_area[MAX_ORDER];
+ spinlock_t lru_lock;
/*
* wait_table -- the array holding the hash table
diff -Nru a/include/linux/module.h b/include/linux/module.h
--- a/include/linux/module.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/module.h Wed Nov 20 17:19:24 2002
@@ -287,6 +287,9 @@
static const char __module_license[] __attribute__((section(".modinfo"))) = \
"license=" license
+#define GPL_HEADER() \
+static const char cpyright="This software may be freely redistributed under the terms of the GNU General Public License.";
+
/* Define the module variable, and usage macros. */
extern struct module __this_module;
@@ -302,7 +305,6 @@
static const char __module_using_checksums[] __attribute__((section(".modinfo"))) =
"using_checksums=1";
#endif
-
#else /* MODULE */
#define MODULE_AUTHOR(name)
@@ -311,6 +313,7 @@
#define MODULE_SUPPORTED_DEVICE(name)
#define MODULE_PARM(var,type)
#define MODULE_PARM_DESC(var,desc)
+#define GPL_HEADER()
/* Create a dummy reference to the table to suppress gcc unused warnings. Put
* the reference in the .data.exit section which is discarded when code is built
diff -Nru a/include/linux/pagemap.h b/include/linux/pagemap.h
--- a/include/linux/pagemap.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/pagemap.h Wed Nov 20 17:19:24 2002
@@ -70,10 +70,6 @@
#define page_hash(mapping,index) (page_hash_table+_page_hashfn(mapping,index))
-extern struct page * __find_get_page(struct address_space *mapping,
- unsigned long index, struct page **hash);
-#define find_get_page(mapping, index) \
- __find_get_page(mapping, index, page_hash(mapping, index))
extern struct page * __find_lock_page (struct address_space * mapping,
unsigned long index, struct page **hash);
extern struct page * find_or_create_page(struct address_space *mapping,
@@ -90,6 +86,13 @@
extern int add_to_page_cache_unique(struct page * page, struct address_space *mapping, unsigned long index, struct page **hash);
extern void ___wait_on_page(struct page *);
+extern int wait_on_page_timeout(struct page *page, int timeout);
+
+
+extern struct page * __find_pagecache_page(struct address_space *mapping,
+ unsigned long index, struct page **hash);
+#define find_pagecache_page(mapping, index) \
+ __find_pagecache_page(mapping, index, page_hash(mapping, index))
static inline void wait_on_page(struct page * page)
{
diff -Nru a/include/linux/swap.h b/include/linux/swap.h
--- a/include/linux/swap.h Wed Nov 20 17:19:24 2002
+++ b/include/linux/swap.h Wed Nov 20 17:19:24 2002
@@ -87,6 +87,7 @@
extern unsigned int nr_free_buffer_pages(void);
extern int nr_active_pages;
extern int nr_inactive_dirty_pages;
+extern int nr_inactive_laundry_pages;
extern int nr_inactive_clean_pages;
extern atomic_t page_cache_size;
extern atomic_t buffermem_pages;
@@ -115,6 +116,7 @@
/* linux/mm/swap.c */
extern void FASTCALL(lru_cache_add(struct page *));
+extern void FASTCALL(lru_cache_add_dirty(struct page *));
extern void FASTCALL(__lru_cache_del(struct page *));
extern void FASTCALL(lru_cache_del(struct page *));
@@ -175,8 +177,6 @@
asmlinkage long sys_swapoff(const char *);
asmlinkage long sys_swapon(const char *, int);
-extern spinlock_cacheline_t pagemap_lru_lock_cacheline;
-#define pagemap_lru_lock pagemap_lru_lock_cacheline.lock
extern void FASTCALL(mark_page_accessed(struct page *));
@@ -191,7 +191,7 @@
/*
* List add/del helper macros. These must be called
- * with the pagemap_lru_lock held!
+ * with the lru lock held!
*/
#define DEBUG_LRU_PAGE(page) \
do { \
diff -Nru a/kernel/ksyms.c b/kernel/ksyms.c
--- a/kernel/ksyms.c Wed Nov 20 17:19:24 2002
+++ b/kernel/ksyms.c Wed Nov 20 17:19:24 2002
@@ -262,7 +262,6 @@
EXPORT_SYMBOL(__pollwait);
EXPORT_SYMBOL(poll_freewait);
EXPORT_SYMBOL(ROOT_DEV);
-EXPORT_SYMBOL(__find_get_page);
EXPORT_SYMBOL(__find_lock_page);
EXPORT_SYMBOL(find_or_create_page);
EXPORT_SYMBOL(grab_cache_page_nowait);
diff -Nru a/mm/filemap.c b/mm/filemap.c
--- a/mm/filemap.c Wed Nov 20 17:19:24 2002
+++ b/mm/filemap.c Wed Nov 20 17:19:24 2002
@@ -55,15 +55,14 @@
spinlock_cacheline_t pagecache_lock_cacheline = {SPIN_LOCK_UNLOCKED};
/*
- * NOTE: to avoid deadlocking you must never acquire the pagemap_lru_lock
+ * NOTE: to avoid deadlocking you must never acquire the lru lock
* with the pagecache_lock held.
*
* Ordering:
* swap_lock ->
- * pagemap_lru_lock ->
+ * lru lock ->
* pagecache_lock
*/
-spinlock_cacheline_t pagemap_lru_lock_cacheline = {SPIN_LOCK_UNLOCKED};
#define CLUSTER_PAGES (1 << page_cluster)
#define CLUSTER_OFFSET(x) (((x) >> page_cluster) << page_cluster)
@@ -183,7 +182,7 @@
head = &inode->i_mapping->clean_pages;
- spin_lock(&pagemap_lru_lock);
+ lru_lock(ALL_ZONES);
spin_lock(&pagecache_lock);
curr = head->next;
@@ -216,7 +215,7 @@
}
spin_unlock(&pagecache_lock);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(ALL_ZONES);
}
static int do_flushpage(struct page *page, unsigned long offset)
@@ -880,6 +879,32 @@
wake_up_all(waitqueue);
}
+
+/* like wait_on_page but with a timeout (in jiffies).
+ * returns 1 on timeout
+ */
+int wait_on_page_timeout(struct page *page, int timeout)
+{
+ wait_queue_head_t *waitqueue = page_waitqueue(page);
+ struct task_struct *tsk = current;
+ DECLARE_WAITQUEUE(wait, tsk);
+
+ if (!PageLocked(page))
+ return 0;
+
+ add_wait_queue(waitqueue, &wait);
+ do {
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ if (!PageLocked(page))
+ break;
+ sync_page(page);
+ timeout = schedule_timeout(timeout);
+ } while (PageLocked(page) && timeout);
+ __set_task_state(tsk, TASK_RUNNING);
+ remove_wait_queue(waitqueue, &wait);
+ return PageLocked(page);
+}
+
/*
* Get a lock on the page, assuming we need to sleep
* to get it..
@@ -914,26 +939,6 @@
__lock_page(page);
}
-/*
- * a rather lightweight function, finding and getting a reference to a
- * hashed page atomically.
- */
-struct page * __find_get_page(struct address_space *mapping,
- unsigned long offset, struct page **hash)
-{
- struct page *page;
-
- /*
- * We scan the hash list read-only. Addition to and removal from
- * the hash-list needs a held write-lock.
- */
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, offset, *hash);
- if (page)
- page_cache_get(page);
- spin_unlock(&pagecache_lock);
- return page;
-}
/*
* Same as above, but trylock it instead of incrementing the count.
@@ -1069,7 +1074,7 @@
* been increased since the last time we were called, we
* stop when the page isn't there.
*/
- spin_lock(&pagemap_lru_lock);
+ lru_lock(ALL_ZONES);
while (--index >= start) {
struct page **hash = page_hash(mapping, index);
spin_lock(&pagecache_lock);
@@ -1079,9 +1084,31 @@
break;
drop_page(page);
}
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(ALL_ZONES);
+}
+
+/*
+ * Look up a page in the pagecache and return that page with
+ * a reference helt
+ */
+struct page * __find_pagecache_page(struct address_space *mapping,
+ unsigned long offset, struct page **hash)
+{
+ struct page *page;
+
+ /*
+ * We scan the hash list read-only. Addition to and removal from
+ * the hash-list needs a held write-lock.
+ */
+ spin_lock(&pagecache_lock);
+ page = __find_page_nolock(mapping, offset, *hash);
+ if (page)
+ page_cache_get(page);
+ spin_unlock(&pagecache_lock);
+ return page;
}
+
/* Same as grab_cache_page, but do not wait if the page is unavailable.
* This is intended for speculative data generators, where the data can
* be regenerated if the page couldn't be grabbed. This routine should
@@ -1092,7 +1119,7 @@
struct page *page, **hash;
hash = page_hash(mapping, index);
- page = __find_get_page(mapping, index, hash);
+ page = __find_pagecache_page(mapping, index, hash);
if ( page ) {
if ( !TryLockPage(page) ) {
@@ -2022,7 +2049,7 @@
*/
hash = page_hash(mapping, pgoff);
retry_find:
- page = __find_get_page(mapping, pgoff, hash);
+ page = __find_pagecache_page(mapping, pgoff, hash);
if (!page)
goto no_cached_page;
@@ -2885,7 +2912,7 @@
struct page *page, *cached_page = NULL;
int err;
repeat:
- page = __find_get_page(mapping, index, hash);
+ page = __find_pagecache_page(mapping, index, hash);
if (!page) {
if (!cached_page) {
cached_page = page_cache_alloc(mapping);
diff -Nru a/mm/page_alloc.c b/mm/page_alloc.c
--- a/mm/page_alloc.c Wed Nov 20 17:19:24 2002
+++ b/mm/page_alloc.c Wed Nov 20 17:19:24 2002
@@ -28,6 +28,7 @@
int nr_swap_pages;
int nr_active_pages;
int nr_inactive_dirty_pages;
+int nr_inactive_laundry_pages;
int nr_inactive_clean_pages;
pg_data_t *pgdat_list;
@@ -113,12 +114,13 @@
BUG();
if (PageInactiveDirty(page))
BUG();
+ if (PageInactiveLaundry(page))
+ BUG();
if (PageInactiveClean(page))
BUG();
if (page->pte_chain)
BUG();
page->flags &= ~((1<<PG_referenced) | (1<<PG_dirty));
- page->age = PAGE_AGE_START;
zone = page_zone(page);
@@ -728,9 +730,10 @@
nr_free_pages() << (PAGE_SHIFT-10),
nr_free_highpages() << (PAGE_SHIFT-10));
- printk("( Active: %d, inactive_dirty: %d, inactive_clean: %d, free: %d )\n",
+ printk("( Active: %d/%d, inactive_laundry: %d, inactive_clean: %d, free: %d )\n",
nr_active_pages,
nr_inactive_dirty_pages,
+ nr_inactive_laundry_pages,
nr_inactive_clean_pages,
nr_free_pages());
@@ -941,12 +944,20 @@
zone->lock = SPIN_LOCK_UNLOCKED;
zone->zone_pgdat = pgdat;
zone->free_pages = 0;
+ zone->active_pages = 0;
zone->inactive_clean_pages = 0;
+ zone->inactive_laundry_pages = 0;
zone->inactive_dirty_pages = 0;
zone->need_balance = 0;
- INIT_LIST_HEAD(&zone->active_list);
+ zone->need_scan = 0;
+ for (k = 0; k <= MAX_AGE ; k++) {
+ INIT_LIST_HEAD(&zone->active_list[k]);
+ zone->active_count[k] = 0;
+ }
INIT_LIST_HEAD(&zone->inactive_dirty_list);
+ INIT_LIST_HEAD(&zone->inactive_laundry_list);
INIT_LIST_HEAD(&zone->inactive_clean_list);
+ spin_lock_init(&zone->lru_lock);
if (!size)
continue;
diff -Nru a/mm/rmap.c b/mm/rmap.c
--- a/mm/rmap.c Wed Nov 20 17:19:24 2002
+++ b/mm/rmap.c Wed Nov 20 17:19:24 2002
@@ -14,7 +14,7 @@
/*
* Locking:
* - the page->pte_chain is protected by the PG_chainlock bit,
- * which nests within the pagemap_lru_lock, then the
+ * which nests within the lru lock, then the
* mm->page_table_lock, and then the page lock.
* - because swapout locking is opposite to the locking order
* in the page fault path, the swapout path uses trylocks
@@ -195,7 +195,7 @@
* table entry mapping a page. Because locking order here is opposite
* to the locking order used by the page fault path, we use trylocks.
* Locking:
- * pagemap_lru_lock page_launder()
+ * lru lock page_launder()
* page lock page_launder(), trylock
* pte_chain_lock page_launder()
* mm->page_table_lock try_to_unmap_one(), trylock
@@ -263,7 +263,7 @@
* @page: the page to get unmapped
*
* Tries to remove all the page table entries which are mapping this
- * page, used in the pageout path. Caller must hold pagemap_lru_lock
+ * page, used in the pageout path. Caller must hold lru lock
* and the page lock. Return values are:
*
* SWAP_SUCCESS - we succeeded in removing all mappings
diff -Nru a/mm/shmem.c b/mm/shmem.c
--- a/mm/shmem.c Wed Nov 20 17:19:24 2002
+++ b/mm/shmem.c Wed Nov 20 17:19:24 2002
@@ -581,7 +581,7 @@
* cache and swap cache. We need to recheck the page cache
* under the protection of the info->lock spinlock. */
- page = find_get_page(mapping, idx);
+ page = find_pagecache_page(mapping, idx);
if (page) {
if (TryLockPage(page))
goto wait_retry;
diff -Nru a/mm/swap.c b/mm/swap.c
--- a/mm/swap.c Wed Nov 20 17:19:24 2002
+++ b/mm/swap.c Wed Nov 20 17:19:24 2002
@@ -36,7 +36,6 @@
/**
* (de)activate_page - move pages from/to active and inactive lists
* @page: the page we want to move
- * @nolock - are we already holding the pagemap_lru_lock?
*
* Deactivate_page will move an active page to the right
* inactive list, while activate_page will move a page back
@@ -51,7 +50,6 @@
* (some pages aren't on any list at all)
*/
ClearPageReferenced(page);
- page->age = 0;
if (PageActive(page)) {
del_page_from_active_list(page);
add_page_to_inactive_dirty_list(page);
@@ -60,9 +58,9 @@
void deactivate_page(struct page * page)
{
- spin_lock(&pagemap_lru_lock);
+ lru_lock(page_zone(page));
deactivate_page_nolock(page);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(page_zone(page));
}
/**
@@ -74,16 +72,16 @@
* on the inactive_clean list it is placed on the inactive_dirty list
* instead.
*
- * Note: this function gets called with the pagemap_lru_lock held.
+ * Note: this function gets called with the lru lock held.
*/
-void drop_page(struct page * page)
+void drop_page_zone(struct zone_struct *zone, struct page * page)
{
if (!TryLockPage(page)) {
if (page->mapping && page->buffers) {
page_cache_get(page);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(zone);
try_to_release_page(page, GFP_NOIO);
- spin_lock(&pagemap_lru_lock);
+ lru_lock(zone);
page_cache_release(page);
}
UnlockPage(page);
@@ -97,12 +95,49 @@
else if (page_count(page) == 1) {
ClearPageReferenced(page);
- page->age = 0;
if (PageActive(page)) {
del_page_from_active_list(page);
+ add_page_to_inactive_dirty_list(page);
+ } else if (PageInactiveDirty(page)) {
+ del_page_from_inactive_dirty_list(page);
+ add_page_to_inactive_laundry_list(page);
+ } else if (PageInactiveLaundry(page)) {
+ del_page_from_inactive_laundry_list(page);
add_page_to_inactive_clean_list(page);
+ }
+ }
+ pte_chain_unlock(page);
+}
+
+void drop_page(struct page * page)
+{
+ if (!TryLockPage(page)) {
+ if (page->mapping && page->buffers) {
+ page_cache_get(page);
+ lru_unlock(ALL_ZONES);
+ try_to_release_page(page, GFP_NOIO);
+ lru_lock(ALL_ZONES);
+ page_cache_release(page);
+ }
+ UnlockPage(page);
+ }
+
+ /* Make sure the page really is reclaimable. */
+ pte_chain_lock(page);
+ if (!page->mapping || PageDirty(page) || page->pte_chain ||
+ page->buffers || page_count(page) > 1)
+ deactivate_page_nolock(page);
+
+ else if (page_count(page) == 1) {
+ ClearPageReferenced(page);
+ if (PageActive(page)) {
+ del_page_from_active_list(page);
+ add_page_to_inactive_dirty_list(page);
} else if (PageInactiveDirty(page)) {
del_page_from_inactive_dirty_list(page);
+ add_page_to_inactive_laundry_list(page);
+ } else if (PageInactiveLaundry(page)) {
+ del_page_from_inactive_laundry_list(page);
add_page_to_inactive_clean_list(page);
}
}
@@ -116,21 +151,22 @@
{
if (PageInactiveDirty(page)) {
del_page_from_inactive_dirty_list(page);
- add_page_to_active_list(page);
+ add_page_to_active_list(page, INITIAL_AGE);
+ } else
+ if (PageInactiveLaundry(page)) {
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_active_list(page, INITIAL_AGE);
} else if (PageInactiveClean(page)) {
del_page_from_inactive_clean_list(page);
- add_page_to_active_list(page);
+ add_page_to_active_list(page, INITIAL_AGE);
}
-
- /* Make sure the page gets a fair chance at staying active. */
- page->age = max((int)page->age, PAGE_AGE_START);
}
void activate_page(struct page * page)
{
- spin_lock(&pagemap_lru_lock);
+ lru_lock(page_zone(page));
activate_page_nolock(page);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(page_zone(page));
}
/**
@@ -140,10 +176,10 @@
void lru_cache_add(struct page * page)
{
if (!PageLRU(page)) {
- spin_lock(&pagemap_lru_lock);
+ lru_lock(page_zone(page));
SetPageLRU(page);
- add_page_to_active_list(page);
- spin_unlock(&pagemap_lru_lock);
+ add_page_to_active_list(page, INITIAL_AGE);
+ lru_unlock(page_zone(page));
}
}
@@ -152,7 +188,7 @@
* @page: the page to add
*
* This function is for when the caller already holds
- * the pagemap_lru_lock.
+ * the lru lock.
*/
void __lru_cache_del(struct page * page)
{
@@ -160,6 +196,8 @@
del_page_from_active_list(page);
} else if (PageInactiveDirty(page)) {
del_page_from_inactive_dirty_list(page);
+ } else if (PageInactiveLaundry(page)) {
+ del_page_from_inactive_laundry_list(page);
} else if (PageInactiveClean(page)) {
del_page_from_inactive_clean_list(page);
}
@@ -172,9 +210,9 @@
*/
void lru_cache_del(struct page * page)
{
- spin_lock(&pagemap_lru_lock);
+ lru_lock(page_zone(page));
__lru_cache_del(page);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(page_zone(page));
}
/*
diff -Nru a/mm/swap_state.c b/mm/swap_state.c
--- a/mm/swap_state.c Wed Nov 20 17:19:24 2002
+++ b/mm/swap_state.c Wed Nov 20 17:19:24 2002
@@ -196,7 +196,7 @@
{
struct page *found;
- found = find_get_page(&swapper_space, entry.val);
+ found = find_pagecache_page(&swapper_space, entry.val);
/*
* Unsafe to assert PageSwapCache and mapping on page found:
* if SMP nothing prevents swapoff from deleting this page from
@@ -224,10 +224,10 @@
/*
* First check the swap cache. Since this is normally
* called after lookup_swap_cache() failed, re-calling
- * that would confuse statistics: use find_get_page()
+ * that would confuse statistics: use find_pagecache_page()
* directly.
*/
- found_page = find_get_page(&swapper_space, entry.val);
+ found_page = find_pagecache_page(&swapper_space, entry.val);
if (found_page)
break;
diff -Nru a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c Wed Nov 20 17:19:24 2002
+++ b/mm/vmscan.c Wed Nov 20 17:19:24 2002
@@ -12,6 +12,7 @@
* to bring the system back to freepages.high: 2.4.97, Rik van Riel.
* Zone aware kswapd started 02/00, Kanoj Sarcar (kanoj@sgi.com).
* Multiqueue VM started 5.8.00, Rik van Riel.
+ * O(1) rmap vm, Arjan van de ven <arjanv@redhat.com>
*/
#include <linux/slab.h>
@@ -37,16 +38,30 @@
*/
#define DEF_PRIORITY (6)
-static inline void age_page_up(struct page *page)
+static inline void age_page_up_nolock(struct page *page, int old_age)
{
- page->age = min((int) (page->age + PAGE_AGE_ADV), PAGE_AGE_MAX);
-}
+ int new_age;
+
+ new_age = old_age+4;
+ if (new_age < 0)
+ new_age = 0;
+ if (new_age > MAX_AGE)
+ new_age = MAX_AGE;
+
+ if (PageActive(page)) {
+ del_page_from_active_list(page);
+ } else if (PageInactiveDirty(page)) {
+ del_page_from_inactive_dirty_list(page);
+ } else if (PageInactiveLaundry(page)) {
+ del_page_from_inactive_laundry_list(page);
+ } else if (PageInactiveClean(page)) {
+ del_page_from_inactive_clean_list(page);
+ } else return;
-static inline void age_page_down(struct page *page)
-{
- page->age -= min(PAGE_AGE_DECL, (int)page->age);
+ add_page_to_active_list(page, new_age);
}
+
/* Must be called with page's pte_chain_lock held. */
static inline int page_mapping_inuse(struct page * page)
{
@@ -84,9 +99,9 @@
/*
* We need to hold the pagecache_lock around all tests to make sure
- * reclaim_page() cannot race with find_get_page() and friends.
+ * reclaim_page() doesn't race with other pagecache users
*/
- spin_lock(&pagemap_lru_lock);
+ lru_lock(zone);
spin_lock(&pagecache_lock);
maxscan = zone->inactive_clean_pages;
while (maxscan-- && !list_empty(&zone->inactive_clean_list)) {
@@ -94,12 +109,7 @@
page = list_entry(page_lru, struct page, lru);
/* Wrong page on list?! (list corruption, should not happen) */
- if (unlikely(!PageInactiveClean(page))) {
- printk("VM: reclaim_page, wrong page on list.\n");
- list_del(page_lru);
- page_zone(page)->inactive_clean_pages--;
- continue;
- }
+ BUG_ON(unlikely(!PageInactiveClean(page)));
/* Page is being freed */
if (unlikely(page_count(page)) == 0) {
@@ -144,7 +154,7 @@
UnlockPage(page);
}
spin_unlock(&pagecache_lock);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(zone);
return NULL;
@@ -152,11 +162,10 @@
__lru_cache_del(page);
pte_chain_unlock(page);
spin_unlock(&pagecache_lock);
- spin_unlock(&pagemap_lru_lock);
+ lru_unlock(zone);
if (entry.val)
swap_free(entry);
UnlockPage(page);
- page->age = PAGE_AGE_START;
if (page_count(page) != 1)
printk("VM: reclaim_page, found page with count %d!\n",
page_count(page));
@@ -164,338 +173,259 @@
}
/**
- * page_dirty - do we need to write the data out to disk
- * @page: page to test
+ * need_rebalance_dirty - do we need to write inactive stuff to disk?
+ * @zone: the zone in question
*
- * Returns true if the page contains data which needs to
- * be written to disk. Doesn't test the page tables (yet?).
+ * Returns true if the zone in question has an inbalance between inactive
+ * dirty on one side and inactive laundry + inactive clean on the other
+ * Right now set the balance at 50%; may need tuning later on
*/
-static inline int page_dirty(struct page *page)
+static inline int need_rebalance_dirty(zone_t * zone)
{
- struct buffer_head *tmp, *bh;
-
- if (PageDirty(page))
+ if (zone->inactive_dirty_pages > zone->inactive_laundry_pages + zone->inactive_clean_pages)
return 1;
- if (page->mapping && !page->buffers)
- return 0;
-
- tmp = bh = page->buffers;
-
- do {
- if (tmp->b_state & ((1<<BH_Dirty) | (1<<BH_Lock)))
- return 1;
- tmp = tmp->b_this_page;
- } while (tmp != bh);
+ return 0;
+}
+/**
+ * need_rebalance_laundry - does the zone have too few inactive_clean pages?
+ * @zone: the zone in question
+ *
+ * Returns true if the zone in question has too few pages in inactive clean
+ * + free
+ */
+static inline int need_rebalance_laundry(zone_t * zone)
+{
+ if (free_low(zone) >= 0)
+ return 1;
return 0;
}
/**
- * page_launder_zone - clean dirty inactive pages, move to inactive_clean list
+ * launder_page - clean dirty page, move to inactive_laundry list
* @zone: zone to free pages in
* @gfp_mask: what operations we are allowed to do
- * @full_flush: full-out page flushing, if we couldn't get enough clean pages
+ * @page: the page at hand, must be on the inactive dirty list
*
- * This function is called when we are low on free / inactive_clean
- * pages, its purpose is to refill the free/clean list as efficiently
- * as possible.
- *
- * This means we do writes asynchronously as long as possible and will
- * only sleep on IO when we don't have another option. Since writeouts
- * cause disk seeks and make read IO slower, we skip writes alltogether
- * when the amount of dirty pages is small.
- *
- * This code is heavily inspired by the FreeBSD source code. Thanks
- * go out to Matthew Dillon.
- */
-int page_launder_zone(zone_t * zone, int gfp_mask, int full_flush)
-{
- int maxscan, cleaned_pages, target, maxlaunder, iopages, over_rsslimit;
- struct list_head * entry, * next;
-
- target = max_t(int, free_plenty(zone), zone->pages_min);
- cleaned_pages = iopages = 0;
-
- /* If we can get away with it, only flush 2 MB worth of dirty pages */
- if (full_flush)
- maxlaunder = 1000000;
- else {
- maxlaunder = min_t(int, 512, zone->inactive_dirty_pages / 4);
- maxlaunder = max(maxlaunder, free_plenty(zone) * 4);
- }
-
- /* The main launder loop. */
- spin_lock(&pagemap_lru_lock);
-rescan:
- maxscan = zone->inactive_dirty_pages;
- entry = zone->inactive_dirty_list.prev;
- next = entry->prev;
- while (maxscan-- && !list_empty(&zone->inactive_dirty_list) &&
- next != &zone->inactive_dirty_list) {
- struct page * page;
-
- /* Low latency reschedule point */
- if (current->need_resched) {
- spin_unlock(&pagemap_lru_lock);
- schedule();
- spin_lock(&pagemap_lru_lock);
- continue;
- }
-
- entry = next;
- next = entry->prev;
- page = list_entry(entry, struct page, lru);
-
- /* This page was removed while we looked the other way. */
- if (!PageInactiveDirty(page))
- goto rescan;
+ * per-zone lru lock is assumed to be held, but this function can drop
+ * it and sleep, so no other locks are allowed to be held.
+ *
+ * returns 0 for failure; 1 for success
+ */
+int launder_page(zone_t * zone, int gfp_mask, struct page *page)
+{
+ int over_rsslimit;
- if (cleaned_pages > target)
- break;
+ /*
+ * Page is being freed, don't worry about it, but report progress.
+ */
+ if (unlikely(page_count(page)) == 0)
+ return 1;
- /* Stop doing IO if we've laundered too many pages already. */
- if (maxlaunder < 0)
- gfp_mask &= ~(__GFP_IO|__GFP_FS);
+ BUG_ON(!PageInactiveDirty(page));
+ del_page_from_inactive_dirty_list(page);
+ add_page_to_inactive_laundry_list(page);
+ /* store the time we start IO */
+ page->age = (jiffies/HZ)&255;
+ /*
+ * The page is locked. IO in progress?
+ * If so, move to laundry and report progress
+ * Acquire PG_locked early in order to safely
+ * access page->mapping.
+ */
+ if (unlikely(TryLockPage(page))) {
+ return 1;
+ }
- /*
- * Page is being freed, don't worry about it.
- */
- if (unlikely(page_count(page)) == 0)
- continue;
+ /*
+ * The page is in active use or really unfreeable. Move to
+ * the active list and adjust the page age if needed.
+ */
+ pte_chain_lock(page);
+ if (page_referenced(page, &over_rsslimit) && !over_rsslimit &&
+ page_mapping_inuse(page)) {
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_active_list(page, INITIAL_AGE);
+ pte_chain_unlock(page);
+ UnlockPage(page);
+ return 1;
+ }
+ /*
+ * Anonymous process memory without backing store. Try to
+ * allocate it some swap space here.
+ *
+ * XXX: implement swap clustering ?
+ */
+ if (page->pte_chain && !page->mapping && !page->buffers) {
/*
- * The page is locked. IO in progress?
- * Acquire PG_locked early in order to safely
- * access page->mapping.
+ * exception to strict LRU ordering:
+ * If we now have plenty of ram free,
+ * don't allocate swap but move the page
+ * to the active list instead. This can
+ * happen with bursty workloads
*/
- if (unlikely(TryLockPage(page))) {
- iopages++;
- continue;
- }
- /*
- * The page is in active use or really unfreeable. Move to
- * the active list and adjust the page age if needed.
- */
- pte_chain_lock(page);
- if (page_referenced(page, &over_rsslimit) && !over_rsslimit &&
- page_mapping_inuse(page)) {
- del_page_from_inactive_dirty_list(page);
- add_page_to_active_list(page);
- page->age = max((int)page->age, PAGE_AGE_START);
+ if (free_high(zone) <= 0) {
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_active_list(page, 0);
pte_chain_unlock(page);
UnlockPage(page);
- continue;
+ return 0;
}
-
- /*
- * Anonymous process memory without backing store. Try to
- * allocate it some swap space here.
- *
- * XXX: implement swap clustering ?
- */
- if (page->pte_chain && !page->mapping && !page->buffers) {
- /* Don't bother if we can't swap it out now. */
- if (maxlaunder < 0) {
- pte_chain_unlock(page);
- UnlockPage(page);
- list_del(entry);
- list_add(entry, &zone->inactive_dirty_list);
- continue;
- }
- page_cache_get(page);
- pte_chain_unlock(page);
- spin_unlock(&pagemap_lru_lock);
- if (!add_to_swap(page)) {
- activate_page(page);
- UnlockPage(page);
- page_cache_release(page);
- spin_lock(&pagemap_lru_lock);
- continue;
- }
+ page_cache_get(page);
+ pte_chain_unlock(page);
+ lru_unlock(zone);
+ if (!add_to_swap(page)) {
+ activate_page(page);
+ lru_lock(zone);
+ UnlockPage(page);
page_cache_release(page);
- spin_lock(&pagemap_lru_lock);
- pte_chain_lock(page);
+ return 0;
}
-
- /*
- * The page is mapped into the page tables of one or more
- * processes. Try to unmap it here.
- */
- if (page->pte_chain && page->mapping) {
- switch (try_to_unmap(page)) {
- case SWAP_ERROR:
- case SWAP_FAIL:
- goto page_active;
- case SWAP_AGAIN:
- pte_chain_unlock(page);
- UnlockPage(page);
- continue;
- case SWAP_SUCCESS:
- ; /* try to free the page below */
- }
+ lru_lock(zone);
+ page_cache_release(page);
+ /* Note: may be on another list ! */
+ if (!PageInactiveLaundry(page)) {
+ UnlockPage(page);
+ return 1;
}
- pte_chain_unlock(page);
-
- if (PageDirty(page) && page->mapping) {
- /*
- * It is not critical here to write it only if
- * the page is unmapped beause any direct writer
- * like O_DIRECT would set the PG_dirty bitflag
- * on the physical page after having successfully
- * pinned it and after the I/O to the page is finished,
- * so the direct writes to the page cannot get lost.
- */
- int (*writepage)(struct page *);
-
- writepage = page->mapping->a_ops->writepage;
- if ((gfp_mask & __GFP_FS) && writepage) {
- ClearPageDirty(page);
- SetPageLaunder(page);
- page_cache_get(page);
- spin_unlock(&pagemap_lru_lock);
-
- writepage(page);
- maxlaunder--;
- iopages++;
- page_cache_release(page);
+ if (unlikely(page_count(page)) == 0) {
+ UnlockPage(page);
+ return 1;
+ }
+ pte_chain_lock(page);
+ }
- spin_lock(&pagemap_lru_lock);
- continue;
- } else {
+ /*
+ * The page is mapped into the page tables of one or more
+ * processes. Try to unmap it here.
+ */
+ if (page->pte_chain && page->mapping) {
+ switch (try_to_unmap(page)) {
+ case SWAP_ERROR:
+ case SWAP_FAIL:
+ goto page_active;
+ case SWAP_AGAIN:
+ pte_chain_unlock(page);
UnlockPage(page);
- list_del(entry);
- list_add(entry, &zone->inactive_dirty_list);
- continue;
- }
+ return 0;
+ case SWAP_SUCCESS:
+ ; /* fall through, try freeing the page below */
+ /* fixme: add a SWAP_MLOCK case */
}
+ }
+ pte_chain_unlock(page);
+ if (PageDirty(page) && page->mapping) {
/*
- * If the page has buffers, try to free the buffer mappings
- * associated with this page. If we succeed we try to free
- * the page as well.
+ * The page can be dirtied after we start writing, but
+ * in that case the dirty bit will simply be set again
+ * and we'll need to write it again.
*/
- if (page->buffers) {
- /* To avoid freeing our page before we're done. */
+ int (*writepage)(struct page *);
+
+ writepage = page->mapping->a_ops->writepage;
+ if ((gfp_mask & __GFP_FS) && writepage) {
+ ClearPageDirty(page);
+ SetPageLaunder(page);
page_cache_get(page);
+ lru_unlock(zone);
- spin_unlock(&pagemap_lru_lock);
+ writepage(page);
- if (try_to_release_page(page, gfp_mask)) {
- if (!page->mapping) {
- /*
- * We must not allow an anon page
- * with no buffers to be visible on
- * the LRU, so we unlock the page after
- * taking the lru lock
- */
- spin_lock(&pagemap_lru_lock);
- UnlockPage(page);
- __lru_cache_del(page);
+ page_cache_release(page);
+ lru_lock(zone);
+ return 1;
+ } else {
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_inactive_dirty_list(page);
+ /* FIXME: this is wrong for !__GFP_FS !!! */
+ UnlockPage(page);
+ return 0;
+ }
+ }
- /* effectively free the page here */
- page_cache_release(page);
+ /*
+ * If the page has buffers, try to free the buffer mappings
+ * associated with this page. If we succeed we try to free
+ * the page as well.
+ */
+ if (page->buffers) {
+ /* To avoid freeing our page before we're done. */
+ page_cache_get(page);
+ lru_unlock(zone);
- cleaned_pages++;
- continue;
- } else {
- /*
- * We freed the buffers but may have
- * slept; undo the stuff we did before
- * try_to_release_page and fall through
- * to the next step.
- * But only if the page is still on the inact. dirty
- * list.
- */
-
- spin_lock(&pagemap_lru_lock);
- /* Check if the page was removed from the list
- * while we looked the other way.
- */
- if (!PageInactiveDirty(page)) {
- page_cache_release(page);
- continue;
- }
- page_cache_release(page);
- }
- } else {
- /* failed to drop the buffers so stop here */
- UnlockPage(page);
- page_cache_release(page);
- maxlaunder--;
- iopages++;
+ try_to_release_page(page, gfp_mask);
+ UnlockPage(page);
- spin_lock(&pagemap_lru_lock);
- continue;
- }
- }
+ /*
+ * If the buffers were the last user of the page we free
+ * the page here. Because of that we shouldn't hold the
+ * lru lock yet.
+ */
+ page_cache_release(page);
+ lru_lock(zone);
+ return 1;
+ }
+ /*
+ * If the page is really freeable now, move it to the
+ * inactive_laundry list to keep LRU order.
+ *
+ * We re-test everything since the page could have been
+ * used by somebody else while we waited on IO above.
+ * This test is not safe from races; only the one in
+ * reclaim_page() needs to be.
+ */
+ pte_chain_lock(page);
+ if (page->mapping && !PageDirty(page) && !page->pte_chain &&
+ page_count(page) == 1) {
+ pte_chain_unlock(page);
+ UnlockPage(page);
+ return 1;
+ } else {
/*
- * If the page is really freeable now, move it to the
- * inactive_clean list.
- *
- * We re-test everything since the page could have been
- * used by somebody else while we waited on IO above.
- * This test is not safe from races, but only the one
- * in reclaim_page() needs to be.
+ * OK, we don't know what to do with the page.
+ * It's no use keeping it here, so we move it
+ * back to the active list.
*/
- pte_chain_lock(page);
- if (page->mapping && !PageDirty(page) && !page->pte_chain &&
- page_count(page) == 1) {
- del_page_from_inactive_dirty_list(page);
- add_page_to_inactive_clean_list(page);
- pte_chain_unlock(page);
- UnlockPage(page);
- cleaned_pages++;
- } else {
- /*
- * OK, we don't know what to do with the page.
- * It's no use keeping it here, so we move it to
- * the active list.
- */
-page_active:
- del_page_from_inactive_dirty_list(page);
- add_page_to_active_list(page);
- pte_chain_unlock(page);
- UnlockPage(page);
- }
+ page_active:
+ activate_page_nolock(page);
+ pte_chain_unlock(page);
+ UnlockPage(page);
}
- spin_unlock(&pagemap_lru_lock);
-
- /* Return the number of pages moved to the inactive_clean list. */
- return cleaned_pages + iopages;
+ return 0;
}
-/**
- * page_launder - clean dirty inactive pages, move to inactive_clean list
- * @gfp_mask: what operations we are allowed to do
- *
- * This function iterates over all zones and calls page_launder_zone(),
- * balancing still needs to be added...
- */
-int page_launder(int gfp_mask)
+
+unsigned char active_age_bias = 0;
+
+/* Ages down all pages on the active list */
+/* assumes the lru lock held */
+static inline void kachunk(struct zone_struct * zone)
{
- struct zone_struct * zone;
- int freed = 0;
+ int k;
+ if (!list_empty(&zone->active_list[0]))
+ return;
+ if (!zone->active_pages)
+ return;
- /* Global balancing while we have a global shortage. */
- if (free_high(ALL_ZONES) >= 0)
- for_each_zone(zone)
- if (free_plenty(zone) >= 0)
- freed += page_launder_zone(zone, gfp_mask, 0);
-
- /* Clean up the remaining zones with a serious shortage, if any. */
- for_each_zone(zone)
- if (free_low(zone) >= 0) {
- int fullflush = free_min(zone) > 0;
- freed += page_launder_zone(zone, gfp_mask, fullflush);
- }
+ for (k = 0; k < MAX_AGE; k++) {
+ list_splice_init(&zone->active_list[k+1], &zone->active_list[k]);
+ zone->active_count[k] = zone->active_count[k+1];
+ zone->active_count[k+1] = 0;
+ }
- return freed;
+ active_age_bias++;
+ /* flag this zone as having had activity -> rescan to age up is desired */
+ zone->need_scan = 1;
}
+#define BATCH_WORK_AMOUNT 64
+
/**
* refill_inactive_zone - scan the active list and find pages to deactivate
* @priority: how much are we allowed to scan
@@ -503,119 +433,265 @@
* This function will scan a portion of the active list of a zone to find
* unused pages, those pages will then be moved to the inactive list.
*/
-int refill_inactive_zone(struct zone_struct * zone, int priority)
+int refill_inactive_zone(struct zone_struct * zone, int priority, int target)
{
int maxscan = zone->active_pages >> priority;
- int nr_deactivated = 0, over_rsslimit;
- int target = inactive_high(zone);
struct list_head * page_lru;
struct page * page;
+ int over_rsslimit;
+ int progress = 0;
/* Take the lock while messing with the list... */
- spin_lock(&pagemap_lru_lock);
- while (maxscan-- && !list_empty(&zone->active_list)) {
- page_lru = zone->active_list.prev;
+ lru_lock(zone);
+ if (target < BATCH_WORK_AMOUNT)
+ target = BATCH_WORK_AMOUNT;
+
+ while (maxscan-- && zone->active_pages > 0 && target > 0) {
+ if (list_empty(&zone->active_list[0])) {
+ kachunk(zone);
+ continue;
+ }
+ page_lru = zone->active_list[0].prev;
page = list_entry(page_lru, struct page, lru);
/* Wrong page on list?! (list corruption, should not happen) */
- if (unlikely(!PageActive(page))) {
- printk("VM: refill_inactive, wrong page on list.\n");
- list_del(page_lru);
- nr_active_pages--;
- continue;
- }
+ BUG_ON(unlikely(!PageActive(page)));
/* Needed to follow page->mapping */
if (TryLockPage(page)) {
- list_del(page_lru);
- list_add(page_lru, &zone->active_list);
+ /* The page is already locked. This for sure means
+ * someone is doing stuff with it which makes it
+ * active by definition ;)
+ */
+ del_page_from_active_list(page);
+ add_page_to_active_list(page, INITIAL_AGE);
continue;
}
/*
- * If the object the page is in is not in use we don't
- * bother with page aging. If the page is touched again
- * while on the inactive_clean list it'll be reactivated.
- * From here until the end of the current iteration
- * both PG_locked and the pte_chain_lock are held.
+ * Do aging on the pages.
*/
- pte_chain_lock(page);
- if (!page_mapping_inuse(page)) {
- pte_chain_unlock(page);
+ if (page_referenced(page, &over_rsslimit) && !over_rsslimit) {
+ age_page_up_nolock(page, 0);
UnlockPage(page);
- drop_page(page);
continue;
}
+ deactivate_page_nolock(page);
+ target--;
+ progress++;
+ UnlockPage(page);
+ }
+ lru_unlock(zone);
+
+ return progress;
+}
+
+static int need_active_scan(struct zone_struct * zone)
+{
+ int low = 0, high = 0;
+ int k;
+ for (k=0; k < MAX_AGE/2; k++)
+ low += zone->active_count[k];
+
+ for (k=MAX_AGE/2; k <= MAX_AGE; k++)
+ high += zone->active_count[k];
+
+ if (high<low)
+ return 1;
+ return 0;
+}
+
+static int scan_active_list(struct zone_struct * zone, int age)
+{
+ struct list_head * list, *page_lru , *next;
+ struct page * page;
+ int over_rsslimit;
+
+ list = &zone->active_list[age];
+
+ /* Take the lock while messing with the list... */
+ lru_lock(zone);
+ list_for_each_safe(page_lru, next, list) {
+ page = list_entry(page_lru, struct page, lru);
+ pte_chain_lock(page);
+ if (page_referenced(page, &over_rsslimit) && !over_rsslimit)
+ age_page_up_nolock(page, age);
+ pte_chain_unlock(page);
+ }
+ lru_unlock(zone);
+ return 0;
+}
+
+/*
+ * Move max_work pages to the inactive clean list as long as there is a need
+ * for this. If gfp_mask allows it, sleep for IO to finish.
+ */
+int rebalance_laundry_zone(struct zone_struct * zone, int max_work, unsigned int gfp_mask)
+{
+ struct list_head * page_lru;
+ int max_loop;
+ int work_done = 0;
+ struct page * page;
+
+ max_loop = max_work;
+ if (max_loop < BATCH_WORK_AMOUNT)
+ max_loop = BATCH_WORK_AMOUNT;
+ /* Take the lock while messing with the list... */
+ lru_lock(zone);
+ while (max_loop-- && !list_empty(&zone->inactive_laundry_list)) {
+ page_lru = zone->inactive_laundry_list.prev;
+ page = list_entry(page_lru, struct page, lru);
+
+ /* Wrong page on list?! (list corruption, should not happen) */
+ BUG_ON(unlikely(!PageInactiveLaundry(page)));
+
+ /* TryLock to see if the page IO is done */
+ if (TryLockPage(page)) {
+ /*
+ * Page is locked (IO in progress?). If we can sleep,
+ * wait for it to finish, except when we've already
+ * done enough work.
+ */
+ if ((gfp_mask & __GFP_WAIT) && (work_done < max_work)) {
+ int timed_out;
+
+ page_cache_get(page);
+ lru_unlock(zone);
+ run_task_queue(&tq_disk);
+ timed_out = wait_on_page_timeout(page, 5 * HZ);
+ lru_lock(zone);
+ page_cache_release(page);
+ /*
+ * If we timed out and the page has been in
+ * flight for over 30 seconds, this might not
+ * be the best page to wait on; move it to
+ * the head of the dirty list.
+ */
+ if (timed_out & PageInactiveLaundry(page)) {
+ unsigned char now;
+ now = (jiffies/HZ)&255;
+ if (now - page->age > 30) {
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_inactive_dirty_list(page);
+ }
+ continue;
+ }
+ /* We didn't make any progress for our caller,
+ * but we are actively avoiding a livelock
+ * so undo the decrement and wait on this page
+ * some more, until IO finishes or we timeout.
+ */
+ max_loop++;
+ continue;
+ } else
+ /* No dice, we can't wait for IO */
+ break;
+ }
+ UnlockPage(page);
+
/*
- * Do aging on the pages.
+ * If we get here either the IO on the page is done or
+ * IO never happened because it was clean. Either way
+ * move it to the inactive clean list.
*/
- if (page_referenced(page, &over_rsslimit)) {
- age_page_up(page);
- } else {
- age_page_down(page);
- }
- /*
- * If the page age is 'hot' and the process using the
- * page doesn't exceed its RSS limit we keep the page.
- * Otherwise we move it to the inactive_dirty list.
+ /* FIXME: check if the page is still clean or is accessed ? */
+
+ del_page_from_inactive_laundry_list(page);
+ add_page_to_inactive_clean_list(page);
+ work_done++;
+
+ /*
+ * If we've done the minimal batch of work and there's
+ * no longer a need to rebalance, abort now.
*/
- if (page->age && !over_rsslimit) {
- list_del(page_lru);
- list_add(page_lru, &zone->active_list);
- } else {
- deactivate_page_nolock(page);
- if (++nr_deactivated > target) {
- pte_chain_unlock(page);
- UnlockPage(page);
- goto done;
- }
- }
- pte_chain_unlock(page);
- UnlockPage(page);
+ if ((work_done > BATCH_WORK_AMOUNT) && (!need_rebalance_laundry(zone)))
+ break;
+ }
- /* Low latency reschedule point */
- if (current->need_resched) {
- spin_unlock(&pagemap_lru_lock);
- schedule();
- spin_lock(&pagemap_lru_lock);
- }
+ lru_unlock(zone);
+ return work_done;
+}
+
+/*
+ * Move max_work pages from the dirty list as long as there is a need.
+ * Start IO if the gfp_mask allows it.
+ */
+int rebalance_dirty_zone(struct zone_struct * zone, int max_work, unsigned int gfp_mask)
+{
+ struct list_head * page_lru;
+ int max_loop;
+ int work_done = 0;
+ struct page * page;
+
+ max_loop = max_work;
+ if (max_loop < BATCH_WORK_AMOUNT)
+ max_loop = BATCH_WORK_AMOUNT;
+ /* Take the lock while messing with the list... */
+ lru_lock(zone);
+ while (max_loop-- && !list_empty(&zone->inactive_dirty_list)) {
+ page_lru = zone->inactive_dirty_list.prev;
+ page = list_entry(page_lru, struct page, lru);
+
+ /* Wrong page on list?! (list corruption, should not happen) */
+ BUG_ON(unlikely(!PageInactiveDirty(page)));
+
+ /*
+ * Note: launder_page() sleeps so we can't safely look at
+ * the page after this point!
+ *
+ * If we fail (only happens if we can't do IO) we just try
+ * again on another page; launder_page makes sure we won't
+ * see the same page over and over again.
+ */
+ if (!launder_page(zone, gfp_mask, page))
+ continue;
+
+ work_done++;
+
+ /*
+ * If we've done the minimal batch of work and there's
+ * no longer any need to rebalance, abort now.
+ */
+ if ((work_done > BATCH_WORK_AMOUNT) && (!need_rebalance_dirty(zone)))
+ break;
}
+ lru_unlock(zone);
-done:
- spin_unlock(&pagemap_lru_lock);
+ return work_done;
+}
- return nr_deactivated;
+/* goal percentage sets the goal of the laundry+clean+free of the total zone size */
+int rebalance_inactive_zone(struct zone_struct * zone, int max_work, unsigned int gfp_mask, int goal_percentage)
+{
+ int ret = 0;
+ /* first deactivate memory */
+ if (((zone->inactive_laundry_pages + zone->inactive_clean_pages + zone->free_pages)*100 < zone->size * goal_percentage) &&
+ (inactive_high(zone) > 0))
+ ret += refill_inactive_zone(zone, 0, max_work + BATCH_WORK_AMOUNT);
+
+ if (need_rebalance_dirty(zone))
+ ret += rebalance_dirty_zone(zone, max_work, gfp_mask);
+ if (need_rebalance_laundry(zone))
+ ret += rebalance_laundry_zone(zone, max_work, gfp_mask);
+ return ret;
}
-/**
- * refill_inactive - checks all zones and refills the inactive list as needed
- *
- * This function tries to balance page eviction from all zones by aging
- * the pages from each zone in the same ratio until the global inactive
- * shortage is resolved. After that it does one last "clean-up" scan to
- * fix up local inactive shortages.
- */
-int refill_inactive(void)
+int rebalance_inactive(unsigned int gfp_mask, int percentage)
{
- int maxtry = 1 << DEF_PRIORITY;
- zone_t * zone;
+ struct zone_struct * zone;
+ int max_work;
int ret = 0;
- /* Global balancing while we have a global shortage. */
- while (maxtry-- && inactive_low(ALL_ZONES) >= 0) {
- for_each_zone(zone) {
- if (inactive_high(zone) >= 0)
- ret += refill_inactive_zone(zone, DEF_PRIORITY);
- }
- }
+ max_work = 4 * BATCH_WORK_AMOUNT;
+ /* If we're in deeper trouble, do more work */
+ if (percentage >= 50)
+ max_work = 8 * BATCH_WORK_AMOUNT;
- /* Local balancing for zones which really need it. */
- for_each_zone(zone) {
- if (inactive_min(zone) >= 0)
- ret += refill_inactive_zone(zone, 0);
- }
+ for_each_zone(zone)
+ ret += rebalance_inactive_zone(zone, max_work, gfp_mask, percentage);
+ /* 4 * BATCH_WORK_AMOUNT needs tuning */
return ret;
}
@@ -636,7 +712,9 @@
for_each_zone(zone)
if (inactive_high(zone) > 0)
- refill_inactive_zone(zone, priority);
+ refill_inactive_zone(zone, priority, BATCH_WORK_AMOUNT);
+ for_each_zone(zone)
+ rebalance_dirty_zone(zone, BATCH_WORK_AMOUNT, GFP_KSWAPD);
}
/*
@@ -655,18 +733,13 @@
* Eat memory from filesystem page cache, buffer cache,
* dentry, inode and filesystem quota caches.
*/
- ret += page_launder(gfp_mask);
+ ret += rebalance_inactive(gfp_mask, 100);
ret += shrink_dcache_memory(DEF_PRIORITY, gfp_mask);
ret += shrink_icache_memory(1, gfp_mask);
#ifdef CONFIG_QUOTA
ret += shrink_dqcache_memory(DEF_PRIORITY, gfp_mask);
#endif
- /*
- * Move pages from the active list to the inactive list.
- */
- refill_inactive();
-
/*
* Reclaim unused slab cache memory.
*/
@@ -682,12 +755,54 @@
* Hmm.. Cache shrink failed - time to kill something?
* Mhwahahhaha! This is the part I really like. Giggle.
*/
- if (ret < free_low(ANY_ZONE))
+ if (ret < free_low(ANY_ZONE) && (gfp_mask&__GFP_WAIT))
out_of_memory();
return ret;
}
+/*
+ * Worker function for kswapd and try_to_free_pages, we get
+ * called whenever there is a shortage of free/inactive_clean
+ * pages.
+ *
+ * This function will also move pages to the inactive list,
+ * if needed.
+ */
+static int do_try_to_free_pages_kswapd(unsigned int gfp_mask)
+{
+ int ret = 0;
+ struct zone_struct * zone;
+
+ ret += shrink_dcache_memory(DEF_PRIORITY, gfp_mask);
+ ret += shrink_icache_memory(DEF_PRIORITY, gfp_mask);
+#ifdef CONFIG_QUOTA
+ ret += shrink_dqcache_memory(DEF_PRIORITY, gfp_mask);
+#endif
+
+ /*
+ * Eat memory from filesystem page cache, buffer cache,
+ * dentry, inode and filesystem quota caches.
+ */
+ rebalance_inactive(gfp_mask, 5);
+
+ for_each_zone(zone)
+ while (need_rebalance_dirty(zone))
+ rebalance_dirty_zone(zone, 16 * BATCH_WORK_AMOUNT, gfp_mask);
+
+ for_each_zone(zone)
+ if (free_high(zone)>0)
+ rebalance_laundry_zone(zone, BATCH_WORK_AMOUNT, 0);
+
+ refill_freelist();
+
+ /* Start IO when needed. */
+ if (free_plenty(ALL_ZONES) > 0 || free_low(ANY_ZONE) > 0)
+ run_task_queue(&tq_disk);
+
+ return ret;
+}
+
/**
* refill_freelist - move inactive_clean pages to free list if needed
*
@@ -764,7 +879,7 @@
* zone is very short on free pages.
*/
if (free_high(ALL_ZONES) >= 0 || free_low(ANY_ZONE) > 0)
- do_try_to_free_pages(GFP_KSWAPD);
+ do_try_to_free_pages_kswapd(GFP_KSWAPD);
refill_freelist();
@@ -846,7 +961,7 @@
/* OK, the VM is very loaded. Sleep instead of using all CPU. */
kswapd_overloaded = 1;
set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(HZ / 4);
+ schedule_timeout(HZ / 40);
kswapd_overloaded = 0;
return;
}
@@ -888,6 +1003,7 @@
void rss_free_pages(unsigned int gfp_mask)
{
long pause = 0;
+ struct zone_struct * zone;
if (current->flags & PF_MEMALLOC)
return;
@@ -895,7 +1011,10 @@
current->flags |= PF_MEMALLOC;
do {
- page_launder(gfp_mask);
+ rebalance_inactive(gfp_mask, 100);
+ for_each_zone(zone)
+ if (free_plenty(zone) >= 0)
+ rebalance_laundry_zone(zone, BATCH_WORK_AMOUNT, 0);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(pause);
@@ -907,11 +1026,52 @@
return;
}
+/*
+ * The background page scanning daemon, started as a kernel thread
+ * from the init process.
+ *
+ * This is the part that background scans the active list to find
+ * pages that are referenced and increases their age score.
+ * It is important that this scan rate is not proportional to vm pressure
+ * per se otherwise cpu usage becomes unbounded. On the other hand, if there's
+ * no VM pressure at all it shouldn't age stuff either otherwise everything
+ * ends up at the maximum age.
+ */
+int kscand(void *unused)
+{
+ struct task_struct *tsk = current;
+ struct zone_struct * zone;
+ int age;
+
+ daemonize();
+ strcpy(tsk->comm, "kscand");
+ sigfillset(&tsk->blocked);
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(10*HZ);
+ for_each_zone(zone) {
+
+
+ if (!need_active_scan(zone))
+ continue;
+ for (age = 0; age < MAX_AGE; age++) {
+ scan_active_list(zone, age);
+ if (current->need_resched)
+ schedule();
+ }
+
+ }
+ }
+}
+
+
static int __init kswapd_init(void)
{
printk("Starting kswapd\n");
swap_setup();
kernel_thread(kswapd, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
+ kernel_thread(kscand, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
return 0;
}
--
Paul P 'Stingray' Komkoff 'Greatest' Jr /// (icq)23200764 /// (http)stingr.net
When you're invisible, the only one really watching you is you (my keychain)
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