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
Raw File
evtchn.h
/******************************************************************************
 * evtchn.h
 *
 * Interface to /dev/xen/evtchn.
 *
 * Copyright (c) 2003-2005, K A Fraser
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef __LINUX_PUBLIC_EVTCHN_H__
#define __LINUX_PUBLIC_EVTCHN_H__

/*
 * Bind a fresh port to VIRQ @virq.
 * Return allocated port.
 */
#define IOCTL_EVTCHN_BIND_VIRQ				\
	_IOC(_IOC_NONE, 'E', 0, sizeof(struct ioctl_evtchn_bind_virq))
struct ioctl_evtchn_bind_virq {
	unsigned int virq;
};

/*
 * Bind a fresh port to remote <@remote_domain, @remote_port>.
 * Return allocated port.
 */
#define IOCTL_EVTCHN_BIND_INTERDOMAIN			\
	_IOC(_IOC_NONE, 'E', 1, sizeof(struct ioctl_evtchn_bind_interdomain))
struct ioctl_evtchn_bind_interdomain {
	unsigned int remote_domain, remote_port;
};

/*
 * Allocate a fresh port for binding to @remote_domain.
 * Return allocated port.
 */
#define IOCTL_EVTCHN_BIND_UNBOUND_PORT			\
	_IOC(_IOC_NONE, 'E', 2, sizeof(struct ioctl_evtchn_bind_unbound_port))
struct ioctl_evtchn_bind_unbound_port {
	unsigned int remote_domain;
};

/*
 * Unbind previously allocated @port.
 */
#define IOCTL_EVTCHN_UNBIND				\
	_IOC(_IOC_NONE, 'E', 3, sizeof(struct ioctl_evtchn_unbind))
struct ioctl_evtchn_unbind {
	unsigned int port;
};

/*
 * Unbind previously allocated @port.
 */
#define IOCTL_EVTCHN_NOTIFY				\
	_IOC(_IOC_NONE, 'E', 4, sizeof(struct ioctl_evtchn_notify))
struct ioctl_evtchn_notify {
	unsigned int port;
};

/* Clear and reinitialise the event buffer. Clear error condition. */
#define IOCTL_EVTCHN_RESET				\
	_IOC(_IOC_NONE, 'E', 5, 0)

#endif /* __LINUX_PUBLIC_EVTCHN_H__ */
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