common/vm/vm_rm.c

	vm_rm.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/sysmacros.h>
#include <sys/errno.h>
#include <sys/signal.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>

#include <vm/hat.h>
#include <vm/as.h>
#include <vm/seg_vn.h>
#include <vm/rm.h>
#include <vm/seg.h>
#include <vm/page.h>

/*
 * Yield the size of an address space.
 *
 * The size can only be used as a hint since we cannot guarantee it
 * will stay the same size unless the as->a_lock is held by the caller.
 */
size_t
rm_assize(struct as *as)
{
    size_t size = 0;
    struct seg *seg;
    struct segvn_data *svd;
    extern struct seg_ops segdev_ops;   /* needs a header file */

    ASSERT(as != NULL && AS_READ_HELD(as, &as->a_lock));

    if (as == &kas)
        return (0);

    for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
        if (seg->s_ops == &segdev_ops &&
            ((SEGOP_GETTYPE(seg, seg->s_base) &
            (MAP_SHARED | MAP_PRIVATE)) == 0)) {
            /*
             * Don't include mappings of /dev/null.  These just
             * reserve address space ranges and have no memory.
             * We cheat by knowing that these segments come
             * from segdev and have no mapping type.
             */
            /* EMPTY */;
        } else if (seg->s_ops == &segvn_ops &&
            (svd = (struct segvn_data *)seg->s_data) != NULL &&
            (svd->vp == NULL || svd->vp->v_type != VREG) &&
            (svd->flags & MAP_NORESERVE)) {
            /*
             * Don't include MAP_NORESERVE pages in the
             * address range unless their mappings have
             * actually materialized.  We cheat by knowing
             * that segvn is the only segment driver that
             * supports MAP_NORESERVE and that the actual
             * number of bytes reserved is in the segment's
             * private data structure.
             */
            size += svd->swresv;
        } else {
            caddr_t addr = seg->s_base;
            size_t segsize = seg->s_size;
            vnode_t *vp;
            vattr_t vattr;

            /*
             * If the segment is mapped beyond the end of the
             * underlying mapped file, if any, then limit the
             * segment's size contribution to the file size.
             */
            vattr.va_mask = AT_SIZE;
            if (seg->s_ops == &segvn_ops &&
                SEGOP_GETVP(seg, addr, &vp) == 0 &&
                vp != NULL && vp->v_type == VREG &&
                VOP_GETATTR(vp, &vattr, ATTR_HINT, CRED()) == 0) {
                u_offset_t filesize = vattr.va_size;
                u_offset_t offset = SEGOP_GETOFFSET(seg, addr);

                if (filesize < offset)
                    filesize = 0;
                else
                    filesize -= offset;
                filesize = P2ROUNDUP_TYPED(filesize, PAGESIZE,
                    u_offset_t);
                if ((u_offset_t)segsize > filesize)
                    segsize = filesize;
            }
            size += segsize;
        }
    }

    return (size);
}

/*
 * Yield the memory claim requirement for an address space.
 *
 * This is currently implemented as the number of active hardware
 * translations that have page structures.  Therefore, it can
 * underestimate the traditional resident set size, eg, if the
 * physical page is present and the hardware translation is missing;
 * and it can overestimate the rss, eg, if there are active
 * translations to a frame buffer with page structs.
 * Also, it does not take sharing and XHATs into account.
 */
size_t
rm_asrss(as)
    register struct as *as;
{
    if (as != (struct as *)NULL && as != &kas)
        return ((size_t)btop(hat_get_mapped_size(as->a_hat)));
    else
        return (0);
}

/*
 * Return a 16-bit binary fraction representing the percent of total memory
 * used by this address space.  Binary point is to right of high-order bit.
 * Defined as the ratio of a_rss for the process to total physical memory.
 * This assumes 2s-complement arithmetic and that shorts and longs are
 * 16 bits and 32 bits, respectively.
 */
ushort_t
rm_pctmemory(struct as *as)
{
    /* This can't overflow */
    ulong_t num = (ulong_t)rm_asrss(as) << (PAGESHIFT-1);
    int shift = 16 - PAGESHIFT;
    ulong_t total = total_pages;

    if (shift < 0) {
        num >>= (-shift);
        shift = 0;
    }
    while (shift > 0 && (num & 0x80000000) == 0) {
        shift--;
        num <<= 1;
    }
    if (shift > 0)
        total >>= shift;

    return (num / total);
}