[PATCH 10/14] Conversion of nr_writeback to per zone counter

Christoph Lameter
2006-06-08T23:03:31Z

Conversion of nr_writeback to per zone counter

Avoids per processor loop during writeback state determination.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.17-rc6-mm1/drivers/base/node.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/drivers/base/node.c 2006-06-08 15:46:37.439311186 -0700
+++ linux-2.6.17-rc6-mm1/drivers/base/node.c 2006-06-08 15:46:56.901973196 -0700
@@ -53,9 +53,6 @@ static ssize_t node_read_meminfo(struct
for (j = 0; j < NR_STAT_ITEMS; j++)
nr[j] = node_page_state(nid, j);

- /* Check for negative values in these approximate counters */
- if ((long)ps.nr_writeback < 0)
- ps.nr_writeback = 0;

n = sprintf(buf, "\n"
"Node %d MemTotal: %8lu kB\n"
@@ -82,7 +79,7 @@ static ssize_t node_read_meminfo(struct
nid, K(i.totalram - i.totalhigh),
nid, K(i.freeram - i.freehigh),
nid, K(nr[NR_DIRTY]),
- nid, K(ps.nr_writeback),
+ nid, K(nr[NR_WRITEBACK]),
nid, K(nr[NR_MAPPED]),
nid, K(nr[NR_PAGECACHE]),
nid, K(nr[NR_SLAB]));
Index: linux-2.6.17-rc6-mm1/fs/proc/proc_misc.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/fs/proc/proc_misc.c 2006-06-08 15:46:37.442240692 -0700
+++ linux-2.6.17-rc6-mm1/fs/proc/proc_misc.c 2006-06-08 15:46:56.902949698 -0700
@@ -189,7 +189,7 @@ static int meminfo_read_proc(char *page,
K(i.totalswap),
K(i.freeswap),
K(global_page_state(NR_DIRTY)),
- K(ps.nr_writeback),
+ K(global_page_state(NR_WRITEBACK)),
K(global_page_state(NR_MAPPED)),
K(global_page_state(NR_SLAB)),
K(allowed),
Index: linux-2.6.17-rc6-mm1/arch/i386/mm/pgtable.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/arch/i386/mm/pgtable.c 2006-06-08 15:46:48.173998029 -0700
+++ linux-2.6.17-rc6-mm1/arch/i386/mm/pgtable.c 2006-06-08 15:47:41.868915289 -0700
@@ -30,7 +30,6 @@ void show_mem(void)
struct page *page;
pg_data_t *pgdat;
unsigned long i;
- struct page_state ps;
unsigned long flags;

printk(KERN_INFO "Mem-info:\n");
@@ -58,9 +57,8 @@ void show_mem(void)
printk(KERN_INFO "%d pages shared\n", shared);
printk(KERN_INFO "%d pages swap cached\n", cached);

- get_page_state(&ps);
printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_DIRTY));
- printk(KERN_INFO "%lu pages writeback\n", ps.nr_writeback);
+ printk(KERN_INFO "%lu pages writeback\n", global_page_state(NR_WRITEBACK));
printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_MAPPED));
printk(KERN_INFO "%lu pages slab\n", global_page_state(NR_SLAB));
printk(KERN_INFO "%lu pages pagetables\n", global_page_state(NR_PAGETABLE));
Index: linux-2.6.17-rc6-mm1/mm/page_alloc.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/mm/page_alloc.c 2006-06-08 15:46:37.436381680 -0700
+++ linux-2.6.17-rc6-mm1/mm/page_alloc.c 2006-06-08 15:46:56.905879204 -0700
@@ -629,7 +629,7 @@ static int rmqueue_bulk(struct zone *zon
}

char *vm_stat_item_descr[NR_STAT_ITEMS] = {
- "mapped", "pagecache", "slab", "pagetable", "dirty"
+ "mapped", "pagecache", "slab", "pagetable", "dirty", "writeback"
};

/*
@@ -1809,7 +1809,7 @@ void show_free_areas(void)
active,
inactive,
global_page_state(NR_DIRTY),
- ps.nr_writeback,
+ global_page_state(NR_WRITEBACK),
ps.nr_unstable,
nr_free_pages(),
global_page_state(NR_SLAB),
@@ -2809,9 +2809,9 @@ static char *vmstat_text[] = {
"nr_slab",
"nr_page_table_pages",
"nr_dirty",
+ "nr_writeback",

/* Page state */
- "nr_writeback",
"nr_unstable",

"pgpgin",
Index: linux-2.6.17-rc6-mm1/include/linux/page-flags.h
===================================================================
--- linux-2.6.17-rc6-mm1.orig/include/linux/page-flags.h 2006-06-08 15:46:37.437358182 -0700
+++ linux-2.6.17-rc6-mm1/include/linux/page-flags.h 2006-06-08 15:46:56.906855706 -0700
@@ -119,7 +119,6 @@
* commented here.
*/
struct page_state {
- unsigned long nr_writeback; /* Pages under writeback */
unsigned long nr_unstable; /* NFS unstable pages */
#define GET_PAGE_STATE_LAST nr_unstable

@@ -349,7 +348,7 @@ void dec_zone_page_state(struct page *,
do { \
if (!test_and_set_bit(PG_writeback, \
&(page)->flags)) \
- inc_page_state(nr_writeback); \
+ inc_zone_page_state(page, NR_WRITEBACK); \
} while (0)
#define TestSetPageWriteback(page) \
({ \
@@ -357,14 +356,14 @@ void dec_zone_page_state(struct page *,
ret = test_and_set_bit(PG_writeback, \
&(page)->flags); \
if (!ret) \
- inc_page_state(nr_writeback); \
+ inc_zone_page_state(page, NR_WRITEBACK); \
ret; \
})
#define ClearPageWriteback(page) \
do { \
if (test_and_clear_bit(PG_writeback, \
&(page)->flags)) \
- dec_page_state(nr_writeback); \
+ dec_zone_page_state(page, NR_WRITEBACK); \
} while (0)
#define TestClearPageWriteback(page) \
({ \
@@ -372,7 +371,7 @@ void dec_zone_page_state(struct page *,
ret = test_and_clear_bit(PG_writeback, \
&(page)->flags); \
if (ret) \
- dec_page_state(nr_writeback); \
+ dec_zone_page_state(page, NR_WRITEBACK); \
ret; \
})

Index: linux-2.6.17-rc6-mm1/mm/page-writeback.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/mm/page-writeback.c 2006-06-08 15:46:37.438334684 -0700
+++ linux-2.6.17-rc6-mm1/mm/page-writeback.c 2006-06-08 15:46:56.907832208 -0700
@@ -112,7 +112,7 @@ static void get_writeback_state(struct w
wbs->nr_dirty = global_page_state(NR_DIRTY);
wbs->nr_unstable = read_page_state(nr_unstable);
wbs->nr_mapped = global_page_state(NR_MAPPED);
- wbs->nr_writeback = read_page_state(nr_writeback);
+ wbs->nr_writeback = global_page_state(NR_WRITEBACK);
}

/*
Index: linux-2.6.17-rc6-mm1/include/linux/mmzone.h
===================================================================
--- linux-2.6.17-rc6-mm1.orig/include/linux/mmzone.h 2006-06-08 15:46:37.438334684 -0700
+++ linux-2.6.17-rc6-mm1/include/linux/mmzone.h 2006-06-08 15:46:56.908808710 -0700
@@ -53,6 +53,7 @@ enum zone_stat_item {
NR_SLAB, /* used by slab allocator */
NR_PAGETABLE, /* used for pagetables */
NR_DIRTY,
+ NR_WRITEBACK,
NR_STAT_ITEMS };

#ifdef CONFIG_SMP
Index: linux-2.6.17-rc6-mm1/mm/swap_prefetch.c
===================================================================
--- linux-2.6.17-rc6-mm1.orig/mm/swap_prefetch.c 2006-06-08 15:46:37.447123203 -0700
+++ linux-2.6.17-rc6-mm1/mm/swap_prefetch.c 2006-06-08 15:46:56.908808710 -0700
@@ -381,7 +381,7 @@ static int prefetch_suitable(void)
get_page_state_node(&ps, node);

/* We shouldn't prefetch when we are doing writeback */
- if (ps.nr_writeback) {
+ if (global_page_state(NR_WRITEBACK)) {
node_clear(node, sp_stat.prefetch_nodes);
continue;
}