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Revision e8a03feb54ca7f1768bbdc2b491f9ef654e6d01d authored by Rik van Riel on 14 April 2010, 21:59:28 UTC, committed by Linus Torvalds on 19 April 2010, 23:28:20 UTC 
rmap: add exclusively owned pages to the newest anon_vma
 
The recent anon_vma fixes cause many anonymous pages to end up
in the parent process anon_vma, even when the page is exclusively
owned by the current process.

Adding exclusively owned anonymous pages to the top anon_vma
reduces rmap scanning overhead, especially in workloads with
forking servers.

This patch adds a parameter to __page_set_anon_rmap that can
be used to indicate whether or not the added page is exclusively
owned by the current process.

Pages added through page_add_new_anon_rmap are exclusively
owned by the current process, and can be added to the top
anon_vma.

Pages added through page_add_anon_rmap can be either shared
or exclusively owned, so we do the conservative thing and
add it to the oldest anon_vma.

A next step would be to add the exclusive parameter to
page_add_anon_rmap, to be used from functions where we do
know for sure whether a page is exclusively owned.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Lightly-tested-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
[ Edited to look nicer  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 9b030e2
Raw File
show_mem.c 
/*
 * Generic show_mem() implementation
 *
 * Copyright (C) 2008 Johannes Weiner <hannes@saeurebad.de>
 * All code subject to the GPL version 2.
 */

#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/quicklist.h>

void show_mem(void)
{
	pg_data_t *pgdat;
	unsigned long total = 0, reserved = 0, shared = 0,
		nonshared = 0, highmem = 0;

	printk("Mem-Info:\n");
	show_free_areas();

	for_each_online_pgdat(pgdat) {
		unsigned long i, flags;

		pgdat_resize_lock(pgdat, &flags);
		for (i = 0; i < pgdat->node_spanned_pages; i++) {
			struct page *page;
			unsigned long pfn = pgdat->node_start_pfn + i;

			if (unlikely(!(i % MAX_ORDER_NR_PAGES)))
				touch_nmi_watchdog();

			if (!pfn_valid(pfn))
				continue;

			page = pfn_to_page(pfn);

			if (PageHighMem(page))
				highmem++;

			if (PageReserved(page))
				reserved++;
			else if (page_count(page) == 1)
				nonshared++;
			else if (page_count(page) > 1)
				shared += page_count(page) - 1;

			total++;
		}
		pgdat_resize_unlock(pgdat, &flags);
	}

	printk("%lu pages RAM\n", total);
#ifdef CONFIG_HIGHMEM
	printk("%lu pages HighMem\n", highmem);
#endif
	printk("%lu pages reserved\n", reserved);
	printk("%lu pages shared\n", shared);
	printk("%lu pages non-shared\n", nonshared);
#ifdef CONFIG_QUICKLIST
	printk("%lu pages in pagetable cache\n",
		quicklist_total_size());
#endif
}
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