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
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
noinitramfs.c
/*
* init/noinitramfs.c
*
* Copyright (C) 2006, NXP Semiconductors, All Rights Reserved
* Author: Jean-Paul Saman <jean-paul.saman@nxp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/kdev_t.h>
#include <linux/syscalls.h>
/*
* Create a simple rootfs that is similar to the default initramfs
*/
static int __init default_rootfs(void)
{
int err;
err = sys_mkdir("/dev", 0755);
if (err < 0)
goto out;
err = sys_mknod((const char __user *) "/dev/console",
S_IFCHR | S_IRUSR | S_IWUSR,
new_encode_dev(MKDEV(5, 1)));
if (err < 0)
goto out;
err = sys_mkdir("/root", 0700);
if (err < 0)
goto out;
return 0;
out:
printk(KERN_WARNING "Failed to create a rootfs\n");
return err;
}
rootfs_initcall(default_rootfs);
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