[patch] arca-vm-19 [Re: Results: Zlatko's new vm patch]

Andrea Arcangeli
1999-01-13T20:57:45Z

I produced a new arca-vm-19. I would like if you could try it. I don't
know if it will work well as previous one...

You could try it on 128Mbyte:

1. with the bootup pager settings (8 2 2 5 32 128 256).
2. after `echo 10 2 2 5 32 128 256 >/proc/sys/vm/pager`
3. after `echo 8 2 2 10 32 128 256 >/proc/sys/vm/pager`
4. after `echo 8 2 2 5 32 32 256 >/proc/sys/vm/pager`
5. after `echo 8 2 2 5 32 128 512 >/proc/sys/vm/pager`
6. after `echo 8 2 2 5 64 128 512 >/proc/sys/vm/pager`

NOTENOTE: if the performances of `1.' are worse than arca-vm-18, don't
_waste_ time trying other pager settings of course ;).

Again the main differeces is free_user_and_cache() implementation. Now I
try to balance the swap cache to the 5% of total memeory during heavy
swapping activities. I do that growing the cache slowly from the point
shrink_mmap start failing. This _seems_ to work pretty well (the cache
levels seems more balanced than arca-vm-18). But again I based the
behavior on an fixed number (this time tunable via sysctl). I tried
inventing some new autotuning algorithm but it seems that everything I
done was performing worse than both arca-vm-18 and arca-vm-19 (the new
below).

Andrea Arcangeli

arca-vm-19 against pre7.gz (in the testing directory), I hope to have
included everything in this diff...

Index: linux/mm/filemap.c
diff -u linux/mm/filemap.c:1.1.1.9 linux/mm/filemap.c:1.1.1.1.2.46
--- linux/mm/filemap.c:1.1.1.9 Thu Jan 7 12:21:35 1999
+++ linux/mm/filemap.c Wed Jan 13 21:23:38 1999
@@ -121,14 +125,11 @@
int shrink_mmap(int priority, int gfp_mask)
{
static unsigned long clock = 0;
- unsigned long limit = num_physpages;
struct page * page;
- int count;
-
- count = (limit << 1) >> priority;
+ unsigned long count = num_physpages / (priority+1);

page = mem_map + clock;
- do {
+ while (count-- != 0) {
int referenced;

/* This works even in the presence of PageSkip because
@@ -147,7 +148,6 @@
clock = page->map_nr;
}

- count--;
referenced = test_and_clear_bit(PG_referenced, &page->flags);

if (PageLocked(page))
@@ -160,21 +160,6 @@
if (atomic_read(&page->count) != 1)
continue;

- /*
- * Is it a page swap page? If so, we want to
- * drop it if it is no longer used, even if it
- * were to be marked referenced..
- */
- if (PageSwapCache(page)) {
- if (referenced && swap_count(page->offset) != 1)
- continue;
- delete_from_swap_cache(page);
- return 1;
- }
-
- if (referenced)
- continue;
-
/* Is it a buffer page? */
if (page->buffers) {
if (buffer_under_min())
@@ -184,6 +169,14 @@
return 1;
}

+ if (referenced)
+ continue;
+
+ if (PageSwapCache(page)) {
+ delete_from_swap_cache(page);
+ return 1;
+ }
+
/* is it a page-cache page? */
if (page->inode) {
if (pgcache_under_min())
@@ -191,8 +184,7 @@
remove_inode_page(page);
return 1;
}
-
- } while (count > 0);
+ }
return 0;
}

Index: linux/mm/mmap.c
diff -u linux/mm/mmap.c:1.1.1.2 linux/mm/mmap.c:1.1.1.1.2.12
--- linux/mm/mmap.c:1.1.1.2 Fri Nov 27 11:19:10 1998
+++ linux/mm/mmap.c Wed Jan 13 21:23:38 1999
@@ -66,7 +66,7 @@
free += page_cache_size;
free += nr_free_pages;
free += nr_swap_pages;
- free -= (page_cache.min_percent + buffer_mem.min_percent + 2)*num_physpages/100;
+ free -= (pager_daemon.cache_min_percent + pager_daemon.buffer_min_percent + 2)*num_physpages/100;
return free > pages;
}

Index: linux/mm/page_alloc.c
diff -u linux/mm/page_alloc.c:1.1.1.8 linux/mm/page_alloc.c:1.1.1.1.2.30
--- linux/mm/page_alloc.c:1.1.1.8 Mon Jan 11 22:24:23 1999
+++ linux/mm/page_alloc.c Wed Jan 13 21:23:38 1999
@@ -124,7 +124,6 @@
if (!PageReserved(page) && atomic_dec_and_test(&page->count)) {
if (PageSwapCache(page))
panic ("Freeing swap cache page");
- page->flags &= ~(1 << PG_referenced);
free_pages_ok(page->map_nr, 0);
return;
}
@@ -141,7 +140,6 @@
if (atomic_dec_and_test(&map->count)) {
if (PageSwapCache(map))
panic ("Freeing swap cache pages");
- map->flags &= ~(1 << PG_referenced);
free_pages_ok(map_nr, order);
return;
}
@@ -212,19 +210,18 @@
* further thought.
*/
if (!(current->flags & PF_MEMALLOC)) {
- static int trashing = 0;
int freed;

if (nr_free_pages > freepages.min) {
- if (!trashing)
+ if (!current->trashing)
goto ok_to_allocate;
if (nr_free_pages > freepages.low) {
- trashing = 0;
+ current->trashing = 0;
goto ok_to_allocate;
}
}

- trashing = 1;
+ current->trashing = 1;
current->flags |= PF_MEMALLOC;
freed = try_to_free_pages(gfp_mask);
current->flags &= ~PF_MEMALLOC;
@@ -353,10 +350,10 @@
unsigned long offset = SWP_OFFSET(entry);
struct swap_info_struct *swapdev = SWP_TYPE(entry) + swap_info;

- offset = (offset >> page_cluster) << page_cluster;
-
for (i = 1 << page_cluster; i > 0; i--) {
- if (offset >= swapdev->max)
+ if (offset >= swapdev->max ||
+ /* don't block on I/O for doing readahead -arca */
+ atomic_read(&nr_async_pages) > pager_daemon.max_async_pages)
return;
if (!swapdev->swap_map[offset] ||
swapdev->swap_map[offset] == SWAP_MAP_BAD ||
Index: linux/mm/page_io.c
diff -u linux/mm/page_io.c:1.1.1.4 linux/mm/page_io.c:1.1.1.1.2.6
--- linux/mm/page_io.c:1.1.1.4 Tue Dec 29 01:39:20 1998
+++ linux/mm/page_io.c Wed Jan 13 00:00:04 1999
@@ -58,7 +58,7 @@
}

/* Don't allow too many pending pages in flight.. */
- if (atomic_read(&nr_async_pages) > pager_daemon.swap_cluster)
+ if (atomic_read(&nr_async_pages) > pager_daemon.max_async_pages)
wait = 1;

p = &swap_info[type];
Index: linux/mm/swap.c
diff -u linux/mm/swap.c:1.1.1.6 linux/mm/swap.c:1.1.1.1.2.13
--- linux/mm/swap.c:1.1.1.6 Mon Jan 11 22:24:24 1999
+++ linux/mm/swap.c Wed Jan 13 21:23:38 1999
@@ -40,41 +40,18 @@
};

/* How many pages do we try to swap or page in/out together? */
-int page_cluster = 4; /* Default value modified in swap_setup() */
+int page_cluster = 5; /* Default readahead 32 pages every time */

/* We track the number of pages currently being asynchronously swapped
out, so that we don't try to swap TOO many pages out at once */
atomic_t nr_async_pages = ATOMIC_INIT(0);

-buffer_mem_t buffer_mem = {
+pager_daemon_t pager_daemon = {
+ 8, /* starting priority of try_to_free_pages() */
2, /* minimum percent buffer */
- 10, /* borrow percent buffer */
- 60 /* maximum percent buffer */
-};
-
-buffer_mem_t page_cache = {
2, /* minimum percent page cache */
- 15, /* borrow percent page cache */
- 75 /* maximum */
-};
-
-pager_daemon_t pager_daemon = {
- 512, /* base number for calculating the number of tries */
- SWAP_CLUSTER_MAX, /* minimum number of tries */
- SWAP_CLUSTER_MAX, /* do swap I/O in clusters of this size */
+ 5, /* minimum percent swap page cache */
+ 32, /* number of tries we do on every try_to_free_pages() */
+ 128, /* do swap I/O in clusters of this size */
+ 256 /* max number of async swapped-out pages on the fly */
};
-
-/*
- * Perform any setup for the swap system
- */
-
-void __init swap_setup(void)
-{
- /* Use a smaller cluster for memory <16MB or <32MB */
- if (num_physpages < ((16 * 1024 * 1024) >> PAGE_SHIFT))
- page_cluster = 2;
- else if (num_physpages < ((32 * 1024 * 1024) >> PAGE_SHIFT))
- page_cluster = 3;
- else
- page_cluster = 4;
-}
Index: linux/mm/swapfile.c
diff -u linux/mm/swapfile.c:1.1.1.3 linux/mm/swapfile.c:1.1.1.1.2.6
--- linux/mm/swapfile.c:1.1.1.3 Mon Jan 11 22:24:24 1999
+++ linux/mm/swapfile.c Wed Jan 13 00:00:04 1999
@@ -23,7 +23,6 @@

struct swap_info_struct swap_info[MAX_SWAPFILES];

-#define SWAPFILE_CLUSTER 256

static inline int scan_swap_map(struct swap_info_struct *si)
{
@@ -31,7 +30,7 @@
/*
* We try to cluster swap pages by allocating them
* sequentially in swap. Once we've allocated
- * SWAPFILE_CLUSTER pages this way, however, we resort to
+ * SWAP_CLUSTER pages this way, however, we resort to
* first-free allocation, starting a new cluster. This
* prevents us from scattering swap pages all over the entire
* swap partition, so that we reduce overall disk seek times
@@ -47,7 +46,7 @@
goto got_page;
}
}
- si->cluster_nr = SWAPFILE_CLUSTER;
+ si->cluster_nr = SWAP_CLUSTER;
for (offset = si->lowest_bit; offset <= si->highest_bit ; offset++) {
if (si->swap_map[offset])
continue;
Index: linux/mm/vmscan.c
diff -u linux/mm/vmscan.c:1.1.1.12 linux/mm/vmscan.c:1.1.1.1.2.91
--- linux/mm/vmscan.c:1.1.1.12 Mon Jan 11 22:24:24 1999
+++ linux/mm/vmscan.c Wed Jan 13 21:23:38 1999
@@ -10,6 +10,11 @@
* Version: $Id: vmscan.c,v 1.5 1998/02/23 22:14:28 sct Exp $
*/

+/*
+ * free_user_and_cache() and always async swapout original idea.
+ * Copyright (C) 1999 Andrea Arcangeli
+ */
+
#include <linux/slab.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
@@ -20,6 +25,8 @@

#include <asm/pgtable.h>

+int swapout_interval = HZ;
+
/*
* The swap-out functions return 1 if they successfully
* threw something out, and we got a free page. It returns
@@ -71,6 +78,21 @@
* memory, and we should just continue our scan.
*/
if (PageSwapCache(page_map)) {
+ if (pte_write(pte))
+ {
+ struct page *found;
+ printk ("VM: Found a writable swap-cached page!\n");
+ /* Try to diagnose the problem ... */
+ found = find_page(&swapper_inode, page_map->offset);
+ if (found) {
+ printk("page=%p@%08lx, found=%p, count=%d\n",
+ page_map, page_map->offset,
+ found, atomic_read(&found->count));
+ __free_page(found);
+ } else
+ printk ("Spurious, page not in cache\n");
+ return 0;
+ }
entry = page_map->offset;
swap_duplicate(entry);
set_pte(page_table, __pte(entry));
@@ -199,7 +221,7 @@

do {
int result;
- tsk->swap_address = address + PAGE_SIZE;
+ tsk->mm->swap_address = address + PAGE_SIZE;
result = try_to_swap_out(tsk, vma, address, pte, gfp_mask);
if (result)
return result;
@@ -271,7 +293,7 @@
/*
* Go through process' page directory.
*/
- address = p->swap_address;
+ address = p->mm->swap_address;

/*
* Find the proper vm-area
@@ -293,8 +315,8 @@
}

/* We didn't find anything for the process */
- p->swap_cnt = 0;
- p->swap_address = 0;
+ p->mm->swap_cnt = 0;
+ p->mm->swap_address = 0;
return 0;
}

@@ -306,7 +328,8 @@
static int swap_out(unsigned int priority, int gfp_mask)
{
struct task_struct * p, * pbest;
- int counter, assign, max_cnt;
+ int counter, assign;
+ unsigned long max_cnt;

/*
* We make one or two passes through the task list, indexed by
@@ -325,7 +348,7 @@
counter = nr_tasks / (priority+1);
if (counter < 1)
counter = 1;
- if (counter > nr_tasks)
+ else if (counter > nr_tasks)
counter = nr_tasks;

for (; counter >= 0; counter--) {
@@ -338,13 +361,13 @@
for (; p != &init_task; p = p->next_task) {
if (!p->swappable)
continue;
- if (p->mm->rss <= 0)
+ if (p->mm->rss == 0)
continue;
/* Refresh swap_cnt? */
if (assign)
- p->swap_cnt = p->mm->rss;
- if (p->swap_cnt > max_cnt) {
- max_cnt = p->swap_cnt;
+ p->mm->swap_cnt = p->mm->rss;
+ if (p->mm->swap_cnt > max_cnt) {
+ max_cnt = p->mm->swap_cnt;
pbest = p;
}
}
@@ -375,8 +398,6 @@
int i;
char *revision="$Revision: 1.5 $", *s, *e;

- swap_setup();
-
if ((s = strchr(revision, ':')) &&
(e = strchr(s, '$')))
s++, i = e - s;
@@ -430,7 +451,7 @@
break;
current->state = TASK_INTERRUPTIBLE;
run_task_queue(&tq_disk);
- schedule_timeout(HZ);
+ schedule_timeout(swapout_interval);

/*
* kswapd isn't even meant to keep up with anything,
@@ -438,13 +459,36 @@
* point is to make sure that the system doesn't stay
* forever in a really bad memory squeeze.
*/
- if (nr_free_pages < freepages.high)
+ if (nr_free_pages < freepages.min)
try_to_free_pages(GFP_KSWAPD);
}

return 0;
}

+static int free_user_and_cache(int priority, int gfp_mask)
+{
+ int freed, swapped = 0;
+ static int grow_swap_cache_mode = 0;
+
+ if (!grow_swap_cache_mode)
+ {
+ freed = shrink_mmap(priority, gfp_mask);
+ if (!freed)
+ {
+ grow_swap_cache_mode = 1;
+ swapped = swap_out(priority, gfp_mask);
+ }
+ } else {
+ if (!swpcache_under_min())
+ grow_swap_cache_mode = 0;
+ swapped = swap_out(priority, gfp_mask);
+ freed = shrink_mmap(priority, gfp_mask);
+ }
+
+ return freed || swapped;
+}
+
/*
* We need to make the locks finer granularity, but right
* now we need this so that we can do page allocations
@@ -457,34 +501,33 @@
int try_to_free_pages(unsigned int gfp_mask)
{
int priority;
- int count = SWAP_CLUSTER_MAX;
+ static int state = 0;
+ int count = pager_daemon.tries;

lock_kernel();
-
- /* Always trim SLAB caches when memory gets low. */
- kmem_cache_reap(gfp_mask);
-
- priority = 6;
- do {
- while (shrink_mmap(priority, gfp_mask)) {
- if (!--count)
- goto done;
- }

- /* Try to get rid of some shared memory pages.. */
- while (shm_swap(priority, gfp_mask)) {
- if (!--count)
- goto done;
- }
-
- /* Then, try to page stuff out.. */
- while (swap_out(priority, gfp_mask)) {
- if (!--count)
- goto done;
- }
+ priority = pager_daemon.priority;
+ switch (state)
+ {
+ do {
+ case 0:
+ while (free_user_and_cache(priority, gfp_mask)) {
+ if (!--count)
+ goto done;
+ }
+ state = 1;
+ case 1:
+ /* Try to get rid of some shared memory pages.. */
+ while (shm_swap(priority, gfp_mask)) {
+ if (!--count)
+ goto done;
+ }
+ state = 0;

- shrink_dcache_memory(priority, gfp_mask);
- } while (--priority >= 0);
+ kmem_cache_reap(gfp_mask);
+ shrink_dcache_memory(priority, gfp_mask);
+ } while (--priority >= 0);
+ }
done:
unlock_kernel();

Index: linux/kernel/fork.c
diff -u linux/kernel/fork.c:1.1.1.6 linux/kernel/fork.c:1.1.1.1.2.10
--- linux/kernel/fork.c:1.1.1.6 Mon Jan 11 22:24:21 1999
+++ linux/kernel/fork.c Mon Jan 11 22:56:09 1999
@@ -511,6 +514,7 @@

p->did_exec = 0;
p->swappable = 0;
+ p->trashing = 0;
p->state = TASK_UNINTERRUPTIBLE;

copy_flags(clone_flags, p);
Index: linux/kernel/sysctl.c
diff -u linux/kernel/sysctl.c:1.1.1.6 linux/kernel/sysctl.c:1.1.1.1.2.12
--- linux/kernel/sysctl.c:1.1.1.6 Mon Jan 11 22:24:22 1999
+++ linux/kernel/sysctl.c Wed Jan 13 21:23:38 1999
@@ -32,7 +32,7 @@

/* External variables not in a header file. */
extern int panic_timeout;
-extern int console_loglevel, C_A_D;
+extern int console_loglevel, C_A_D, swapout_interval;
extern int bdf_prm[], bdflush_min[], bdflush_max[];
extern char binfmt_java_interpreter[], binfmt_java_appletviewer[];
extern int sysctl_overcommit_memory;
@@ -216,6 +216,8 @@
};

static ctl_table vm_table[] = {
+ {VM_SWAPOUT, "swapout_interval",
+ &swapout_interval, sizeof(int), 0644, NULL, &proc_dointvec},
{VM_FREEPG, "freepages",
&freepages, sizeof(freepages_t), 0644, NULL, &proc_dointvec},
{VM_BDFLUSH, "bdflush", &bdf_prm, 9*sizeof(int), 0600, NULL,
@@ -223,11 +225,7 @@
&bdflush_min, &bdflush_max},
{VM_OVERCOMMIT_MEMORY, "overcommit_memory", &sysctl_overcommit_memory,
sizeof(sysctl_overcommit_memory), 0644, NULL, &proc_dointvec},
- {VM_BUFFERMEM, "buffermem",
- &buffer_mem, sizeof(buffer_mem_t), 0644, NULL, &proc_dointvec},
- {VM_PAGECACHE, "pagecache",
- &page_cache, sizeof(buffer_mem_t), 0644, NULL, &proc_dointvec},
- {VM_PAGERDAEMON, "kswapd",
+ {VM_PAGERDAEMON, "pager",
&pager_daemon, sizeof(pager_daemon_t), 0644, NULL, &proc_dointvec},
{VM_PGT_CACHE, "pagetable_cache",
&pgt_cache_water, 2*sizeof(int), 0600, NULL, &proc_dointvec},
Index: linux/include/linux/mm.h
diff -u linux/include/linux/mm.h:1.1.1.6 linux/include/linux/mm.h:1.1.1.1.2.20
--- linux/include/linux/mm.h:1.1.1.6 Mon Jan 11 22:23:57 1999
+++ linux/include/linux/mm.h Wed Jan 13 21:23:36 1999
@@ -118,7 +118,6 @@
unsigned long offset;
struct page *next_hash;
atomic_t count;
- unsigned int unused;
unsigned long flags; /* atomic flags, some possibly updated asynchronously */
struct wait_queue *wait;
struct page **pprev_hash;
@@ -302,8 +301,7 @@

/* filemap.c */
extern void remove_inode_page(struct page *);
-extern unsigned long page_unuse(struct page *);
-extern int shrink_mmap(int, int);
+extern int FASTCALL(shrink_mmap(int, int));
extern void truncate_inode_pages(struct inode *, unsigned long);
extern unsigned long get_cached_page(struct inode *, unsigned long, int);
extern void put_cached_page(unsigned long);
@@ -387,9 +385,11 @@
}

#define buffer_under_min() ((buffermem >> PAGE_SHIFT) * 100 < \
- buffer_mem.min_percent * num_physpages)
-#define pgcache_under_min() (page_cache_size * 100 < \
- page_cache.min_percent * num_physpages)
+ pager_daemon.buffer_min_percent * num_physpages)
+#define pgcache_under_min() ((page_cache_size-swapper_inode.i_nrpages) * 100 < \
+ pager_daemon.cache_min_percent * num_physpages)
+#define swpcache_under_min() (swapper_inode.i_nrpages * 100 < \
+ pager_daemon.swap_min_percent * num_physpages)

#endif /* __KERNEL__ */

Index: linux/include/linux/sched.h
diff -u linux/include/linux/sched.h:1.1.1.6 linux/include/linux/sched.h:1.1.1.1.2.12
--- linux/include/linux/sched.h:1.1.1.6 Mon Jan 11 22:24:03 1999
+++ linux/include/linux/sched.h Wed Jan 13 00:00:03 1999
@@ -169,6 +174,7 @@
unsigned long rss, total_vm, locked_vm;
unsigned long def_flags;
unsigned long cpu_vm_mask;
+ unsigned long swap_cnt, swap_address;
/*
* This is an architecture-specific pointer: the portable
* part of Linux does not know about any segments.
@@ -177,15 +183,17 @@
};

#define INIT_MM { \
- &init_mmap, NULL, swapper_pg_dir, \
+ &init_mmap, NULL, swapper_pg_dir, \
ATOMIC_INIT(1), 1, \
MUTEX, \
0, \
0, 0, 0, 0, \
- 0, 0, 0, \
+ 0, 0, 0, \
0, 0, 0, 0, \
0, 0, 0, \
- 0, 0, NULL }
+ 0, 0, \
+ 0, 0, \
+ NULL }

struct signal_struct {
atomic_t count;
@@ -270,8 +278,7 @@
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
int swappable:1;
- unsigned long swap_address;
- unsigned long swap_cnt; /* number of pages to swap on next pass */
+ int trashing:1;
/* process credentials */
uid_t uid,euid,suid,fsuid;
gid_t gid,egid,sgid,fsgid;
@@ -355,7 +362,7 @@
/* utime */ {0,0,0,0},0, \
/* per CPU times */ {0, }, {0, }, \
/* flt */ 0,0,0,0,0,0, \
-/* swp */ 0,0,0, \
+/* swp */ 0,0, \
/* process credentials */ \
/* uid etc */ 0,0,0,0,0,0,0,0, \
/* suppl grps*/ 0, {0,}, \
Index: linux/include/linux/swapctl.h
diff -u linux/include/linux/swapctl.h:1.1.1.4 linux/include/linux/swapctl.h:1.1.1.1.2.5
--- linux/include/linux/swapctl.h:1.1.1.4 Mon Jan 11 22:24:05 1999
+++ linux/include/linux/swapctl.h Wed Jan 13 21:23:36 1999
@@ -4,32 +4,24 @@
#include <asm/page.h>
#include <linux/fs.h>

-typedef struct buffer_mem_v1
+typedef struct freepages_s
{
- unsigned int min_percent;
- unsigned int borrow_percent;
- unsigned int max_percent;
-} buffer_mem_v1;
-typedef buffer_mem_v1 buffer_mem_t;
-extern buffer_mem_t buffer_mem;
-extern buffer_mem_t page_cache;
-
-typedef struct freepages_v1
-{
unsigned int min;
unsigned int low;
unsigned int high;
-} freepages_v1;
-typedef freepages_v1 freepages_t;
+} freepages_t;
extern freepages_t freepages;

-typedef struct pager_daemon_v1
+typedef struct pager_daemon_s
{
- unsigned int tries_base;
- unsigned int tries_min;
+ unsigned int priority;
+ unsigned int buffer_min_percent;
+ unsigned int cache_min_percent;
+ unsigned int swap_min_percent;
+ unsigned int tries;
unsigned int swap_cluster;
-} pager_daemon_v1;
-typedef pager_daemon_v1 pager_daemon_t;
+ unsigned int max_async_pages;
+} pager_daemon_t;
extern pager_daemon_t pager_daemon;

#endif /* _LINUX_SWAPCTL_H */
Index: linux/include/linux/swap.h
diff -u linux/include/linux/swap.h:1.1.1.6 linux/include/linux/swap.h:1.1.1.1.2.17
--- linux/include/linux/swap.h:1.1.1.6 Mon Jan 11 22:24:05 1999
+++ linux/include/linux/swap.h Wed Jan 13 21:28:52 1999
@@ -33,7 +33,7 @@
#define SWP_USED 1
#define SWP_WRITEOK 3

-#define SWAP_CLUSTER_MAX 32
+#define SWAP_CLUSTER (pager_daemon.swap_cluster)

#define SWAP_MAP_MAX 0x7fff
#define SWAP_MAP_BAD 0x8000
@@ -68,9 +68,6 @@

/* linux/ipc/shm.c */
extern int shm_swap (int, int);
-
-/* linux/mm/swap.c */
-extern void swap_setup (void);

/* linux/mm/vmscan.c */
extern int try_to_free_pages(unsigned int gfp_mask);