Commit 40c99aae authored by Chandra Seetharaman's avatar Chandra Seetharaman Committed by Linus Torvalds
Browse files

[PATCH] remove static variable mm/page-writeback.c:total_pages 



page-writeback.c has a static local variable "total_pages", which is the
total number of pages in the system.

There is a global variable "vm_total_pages", which is the total number of
pages the VM controls.

Both are assigned from the return value of nr_free_pagecache_pages().

This patch removes the local variable and uses the global variable in that
place.

One more issue with the local static variable "total_pages" is that it is
not updated when new pages are hot-added.  Since vm_total_pages is updated
when new pages are hot-added, this patch fixes that problem too.

Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 153dcc54

mm/page-writeback.c

+4 −7
Original line number Diff line number Diff line
@@ -46,7 +46,6 @@ 
 */

static long ratelimit_pages = 32;



static long total_pages;	/* The total number of pages in the machine. */

static int dirty_exceeded __cacheline_aligned_in_smp;	/* Dirty mem may be over limit */



/*
@@ -126,7 +125,7 @@ get_dirty_limits(long *pbackground, long *pdirty, 
	int unmapped_ratio;

	long background;

	long dirty;

	unsigned long available_memory = total_pages;

	unsigned long available_memory = vm_total_pages;

	struct task_struct *tsk;



#ifdef CONFIG_HIGHMEM
@@ -141,7 +140,7 @@ get_dirty_limits(long *pbackground, long *pdirty, 


	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +

				global_page_state(NR_ANON_PAGES)) * 100) /

					total_pages;

					vm_total_pages;



	dirty_ratio = vm_dirty_ratio;

	if (dirty_ratio > unmapped_ratio / 2)
@@ -504,7 +503,7 @@ void laptop_sync_completion(void) 


static void set_ratelimit(void)

{

	ratelimit_pages = total_pages / (num_online_cpus() * 32);

	ratelimit_pages = vm_total_pages / (num_online_cpus() * 32);

	if (ratelimit_pages < 16)

		ratelimit_pages = 16;

	if (ratelimit_pages * PAGE_CACHE_SIZE > 4096 * 1024)
@@ -533,9 +532,7 @@ void __init page_writeback_init(void) 
	long buffer_pages = nr_free_buffer_pages();

	long correction;



	total_pages = nr_free_pagecache_pages();



	correction = (100 * 4 * buffer_pages) / total_pages;

	correction = (100 * 4 * buffer_pages) / vm_total_pages;



	if (correction < 100) {

		dirty_background_ratio *= correction;

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