usr/src/sys/kern/kern_malloc.c

/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)kern_malloc.c       7.12.1.1 (Berkeley) %G%
 */

#include "param.h"
#include "vm.h"
#include "cmap.h"
#include "time.h"
#include "proc.h"
#include "map.h"
#include "kernel.h"
#include "malloc.h"

#include "machine/pte.h"

struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
long wantkmemmap;
long malloc_reentered;
#define IN { if (malloc_reentered) panic("malloc reentered");\
                        else malloc_reentered = 1;}
#define OUT (malloc_reentered = 0)

/*
 * Allocate a block of memory
 */
qaddr_t
malloc(size, type, flags)
        unsigned long size;
        int type, flags;
{
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
        long indx, npg, alloc, allocsize;
        int s;
        caddr_t va, cp;
#ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];

        if (((unsigned long)type) > M_LAST)
                panic("malloc - bogus type");
#endif

        indx = BUCKETINDX(size);
        kbp = &bucket[indx];
        s = splimp();
        IN;
again:
#ifdef KMEMSTATS
        while (ksp->ks_memuse >= ksp->ks_limit) {
                if (flags & M_NOWAIT) {
                        OUT;
                        splx(s);
                        return (0);
                }
                if (ksp->ks_limblocks < 65535)
                        ksp->ks_limblocks++;
                OUT;
                sleep((caddr_t)ksp, PSWP+2);
                IN;
        }
#endif
        if (kbp->kb_next == NULL) {
                if (size > MAXALLOCSAVE)
                        allocsize = roundup(size, CLBYTES);
                else
                        allocsize = 1 << indx;
                npg = clrnd(btoc(allocsize));
                if ((flags & M_NOWAIT) && freemem < npg) {
                        OUT;
                        splx(s);
                        return (0);
                }
                alloc = rmalloc(kmemmap, npg);
                if (alloc == 0) {
                        if (flags & M_NOWAIT) {
                                OUT;
                                splx(s);
                                return (0);
                        }
#ifdef KMEMSTATS
                        if (ksp->ks_mapblocks < 65535)
                                ksp->ks_mapblocks++;
#endif
                        wantkmemmap++;
                        OUT;
                        sleep((caddr_t)&wantkmemmap, PSWP+2);
                        IN;
                        goto again;
                }
                alloc -= CLSIZE;                /* convert to base 0 */
                (void) vmemall(&kmempt[alloc], (int)npg, &proc[0], CSYS);
                va = (caddr_t) kmemxtob(alloc);
                vmaccess(&kmempt[alloc], va, (int)npg);
#ifdef KMEMSTATS
                kbp->kb_total += kbp->kb_elmpercl;
#endif
                kup = btokup(va);
                kup->ku_indx = indx;
                if (allocsize > MAXALLOCSAVE) {
                        if (npg > 65535)
                                panic("malloc: allocation too large");
                        kup->ku_pagecnt = npg;
#ifdef KMEMSTATS
                        ksp->ks_memuse += allocsize;
#endif
                        goto out;
                }
#ifdef KMEMSTATS
                kup->ku_freecnt = kbp->kb_elmpercl;
                kbp->kb_totalfree += kbp->kb_elmpercl;
#endif
                kbp->kb_next = va + (npg * NBPG) - allocsize;
                for (cp = kbp->kb_next; cp >= va; cp -= allocsize) {
                        ((caddr_t *)cp)[2] = (cp > va ? cp - allocsize : NULL);
                        if (indx == 7) {
                                long *lp = (long *)cp;
                                lp[0] = lp[1] = lp[3] = lp[4] = -1;
                        }
                }
        }
        va = kbp->kb_next;
        kbp->kb_next = ((caddr_t *)va)[2];
        if (indx == 7) {
                long *lp = (long *)va;
                if (lp[0] != -1 || lp[1] != -1 || lp[3] != -1 || lp[4] != -1)
                        panic("malloc meddled");
        }
#ifdef KMEMSTATS
        kup = btokup(va);
        if (kup->ku_indx != indx)
                panic("malloc: wrong bucket");
        if (kup->ku_freecnt == 0)
                panic("malloc: lost data");
        kup->ku_freecnt--;
        kbp->kb_totalfree--;
        ksp->ks_memuse += 1 << indx;
out:
        kbp->kb_calls++;
        ksp->ks_inuse++;
        ksp->ks_calls++;
        if (ksp->ks_memuse > ksp->ks_maxused)
                ksp->ks_maxused = ksp->ks_memuse;
#else
out:
#endif
        OUT;
        splx(s);
        return ((qaddr_t)va);
}

/*
 * Free a block of memory allocated by malloc.
 */
void
free(addr, type)
        caddr_t addr;
        int type;
{
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
        long alloc, size;
        int s;
#ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];
#endif

        kup = btokup(addr);
        kbp = &bucket[kup->ku_indx];
        s = splimp();
        IN;
        size = 1 << kup->ku_indx;
        if (size > MAXALLOCSAVE) {
                alloc = btokmemx(addr);
                (void) memfree(&kmempt[alloc], (int)kup->ku_pagecnt, 0);
                rmfree(kmemmap, (long)kup->ku_pagecnt, alloc + CLSIZE);
                OUT;
                if (wantkmemmap) {
                        wakeup((caddr_t)&wantkmemmap);
                        wantkmemmap = 0;
                }
#ifdef KMEMSTATS
                size = kup->ku_pagecnt << PGSHIFT;
                ksp->ks_memuse -= size;
                kup->ku_indx = 0;
                kup->ku_pagecnt = 0;
                if (ksp->ks_memuse + size >= ksp->ks_limit &&
                    ksp->ks_memuse < ksp->ks_limit)
                        wakeup((caddr_t)ksp);
                ksp->ks_inuse--;
                kbp->kb_total -= 1;
#endif
                splx(s);
                return;
        }
        if (size == 128) {
                long *lp = (long *)addr;
                lp[0] = lp[1] = lp[3] = lp[4] = -1;
        }
#ifdef KMEMSTATS
        kup->ku_freecnt++;
        if (kup->ku_freecnt >= kbp->kb_elmpercl)
                if (kup->ku_freecnt > kbp->kb_elmpercl)
                        panic("free: multiple frees");
                else if (kbp->kb_totalfree > kbp->kb_highwat)
                        kbp->kb_couldfree++;
        kbp->kb_totalfree++;
        ksp->ks_memuse -= size;
        if (ksp->ks_memuse + size >= ksp->ks_limit &&
            ksp->ks_memuse < ksp->ks_limit)
                wakeup((caddr_t)ksp);
        ksp->ks_inuse--;
#endif
        ((caddr_t *)addr)[2] = kbp->kb_next;
        kbp->kb_next = addr;
        OUT;
        splx(s);
}

/*
 * Initialize the kernel memory allocator
 */
kmeminit()
{
        register long indx;
        int npg;

#if     ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0)
                ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2
#endif
#if     (MAXALLOCSAVE > MINALLOCSIZE * 32768)
                ERROR!_kmeminit:_MAXALLOCSAVE_too_big
#endif
#if     (MAXALLOCSAVE < CLBYTES)
                ERROR!_kmeminit:_MAXALLOCSAVE_too_small
#endif
        npg = ekmempt - kmempt;
        rminit(kmemmap, (long)npg, (long)CLSIZE, "malloc map", npg);
#ifdef KMEMSTATS
        for (indx = 0; indx < MINBUCKET + 16; indx++) {
                if (1 << indx >= CLBYTES)
                        bucket[indx].kb_elmpercl = 1;
                else
                        bucket[indx].kb_elmpercl = CLBYTES / (1 << indx);
                bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
        }
        for (indx = 0; indx < M_LAST; indx++)
                kmemstats[indx].ks_limit = npg * CLBYTES * 8 / 10;
#endif
}