freebsd-src/lib/libkvm/kvm_getswapinfo.c
Peter Wemm c4a7cdb3b6 Use kldsym(2) to lookup symbol values. This avoids the kvm_mkdb juggling
and is module aware.  Yes, this means that kvm_nlist(3) will find symbols
in loaded modules.  The emulation of the nlist struct is pretty crude but
seems to work well enough for all the users in the tree that I found.
1999-12-27 07:14:58 +00:00

420 lines
8.1 KiB
C

/*
* Copyright (c) 1999, Matthew Dillon. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided under the terms of the BSD
* Copyright as found in /usr/src/COPYRIGHT in the FreeBSD source tree.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1999\n"
"Matthew Dillon. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/ucred.h>
#include <sys/stat.h>
#include <sys/conf.h>
#include <sys/blist.h>
#include <err.h>
#include <fcntl.h>
#include <kvm.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static struct nlist kvm_swap_nl[] = {
{ "_swapblist" }, /* new radix swap list */
{ "_swdevt" }, /* list of swap devices and sizes */
{ "_nswdev" }, /* number of swap devices */
{ "_dmmax" }, /* maximum size of a swap block */
{ "" }
};
#define NL_SWAPBLIST 0
#define NL_SWDEVT 1
#define NL_NSWDEV 2
#define NL_DMMAX 3
static int kvm_swap_nl_cached = 0;
static int nswdev;
static int unswdev;
static int dmmax;
static void getswapinfo_radix(kvm_t *kd, struct kvm_swap *swap_ary,
int swap_max, int flags);
#define SVAR(var) __STRING(var) /* to force expansion */
#define KGET(idx, var) \
KGET1(idx, &var, sizeof(var), SVAR(var))
#define KGET1(idx, p, s, msg) \
KGET2(kvm_swap_nl[idx].n_value, p, s, msg)
#define KGET2(addr, p, s, msg) \
if (kvm_read(kd, (u_long)(addr), p, s) != s) \
warnx("cannot read %s: %s", msg, kvm_geterr(kd))
#define KGETN(idx, var) \
KGET1N(idx, &var, sizeof(var), SVAR(var))
#define KGET1N(idx, p, s, msg) \
KGET2N(kvm_swap_nl[idx].n_value, p, s, msg)
#define KGET2N(addr, p, s, msg) \
((kvm_read(kd, (u_long)(addr), p, s) == s) ? 1 : 0)
#define KGETRET(addr, p, s, msg) \
if (kvm_read(kd, (u_long)(addr), p, s) != s) { \
warnx("cannot read %s: %s", msg, kvm_geterr(kd)); \
return (0); \
}
int
kvm_getswapinfo(
kvm_t *kd,
struct kvm_swap *swap_ary,
int swap_max,
int flags
) {
int ti = 0;
/*
* clear cache
*/
if (kd == NULL) {
kvm_swap_nl_cached = 0;
return(0);
}
/*
* namelist
*/
if (kvm_swap_nl_cached == 0) {
struct swdevt *sw;
if (kvm_nlist(kd, kvm_swap_nl) < 0)
return(-1);
/*
* required entries
*/
if (
kvm_swap_nl[NL_SWDEVT].n_value == 0 ||
kvm_swap_nl[NL_NSWDEV].n_value == 0 ||
kvm_swap_nl[NL_DMMAX].n_value == 0 ||
kvm_swap_nl[NL_SWAPBLIST].n_type == 0
) {
return(-1);
}
/*
* get globals, type of swap
*/
KGET(NL_NSWDEV, nswdev);
KGET(NL_DMMAX, dmmax);
/*
* figure out how many actual swap devices are enabled
*/
KGET(NL_SWDEVT, sw);
for (unswdev = nswdev - 1; unswdev >= 0; --unswdev) {
struct swdevt swinfo;
KGET2(&sw[unswdev], &swinfo, sizeof(swinfo), "swinfo");
if (swinfo.sw_nblks)
break;
}
++unswdev;
kvm_swap_nl_cached = 1;
}
{
struct swdevt *sw;
int i;
ti = unswdev;
if (ti >= swap_max)
ti = swap_max - 1;
if (ti >= 0)
bzero(swap_ary, sizeof(struct kvm_swap) * (ti + 1));
KGET(NL_SWDEVT, sw);
for (i = 0; i < unswdev; ++i) {
struct swdevt swinfo;
int ttl;
KGET2(&sw[i], &swinfo, sizeof(swinfo), "swinfo");
/*
* old style: everything in DEV_BSIZE'd chunks,
* convert to pages.
*
* new style: swinfo in DEV_BSIZE'd chunks but dmmax
* in pages.
*
* The first dmmax is never allocating to avoid
* trashing the disklabels
*/
ttl = swinfo.sw_nblks - dmmax;
if (ttl == 0)
continue;
if (i < ti) {
swap_ary[i].ksw_total = ttl;
swap_ary[i].ksw_used = ttl;
swap_ary[i].ksw_flags = swinfo.sw_flags;
if (swinfo.sw_dev == NODEV) {
snprintf(
swap_ary[i].ksw_devname,
sizeof(swap_ary[i].ksw_devname),
"%s",
"[NFS swap]"
);
} else {
snprintf(
swap_ary[i].ksw_devname,
sizeof(swap_ary[i].ksw_devname),
"%s%s",
((flags & SWIF_DEV_PREFIX) ? "/dev/" : ""),
devname(swinfo.sw_dev, S_IFCHR)
);
}
}
if (ti >= 0) {
swap_ary[ti].ksw_total += ttl;
swap_ary[ti].ksw_used += ttl;
}
}
}
getswapinfo_radix(kd, swap_ary, swap_max, flags);
return(ti);
}
/*
* scanradix() - support routine for radix scanner
*/
#define TABME tab, tab, ""
static int
scanradix(
blmeta_t *scan,
daddr_t blk,
daddr_t radix,
daddr_t skip,
daddr_t count,
kvm_t *kd,
int dmmax,
int nswdev,
struct kvm_swap *swap_ary,
int swap_max,
int tab,
int flags
) {
blmeta_t meta;
int ti = (unswdev >= swap_max) ? swap_max - 1 : unswdev;
KGET2(scan, &meta, sizeof(meta), "blmeta_t");
/*
* Terminator
*/
if (meta.bm_bighint == (daddr_t)-1) {
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s(0x%06x,%d) Terminator\n",
TABME,
blk,
radix
);
}
return(-1);
}
if (radix == BLIST_BMAP_RADIX) {
/*
* Leaf bitmap
*/
int i;
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s(0x%06x,%d) Bitmap %08x big=%d\n",
TABME,
blk,
radix,
(int)meta.u.bmu_bitmap,
meta.bm_bighint
);
}
/*
* If not all allocated, count.
*/
if (meta.u.bmu_bitmap != 0) {
for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
/*
* A 0 bit means allocated
*/
if ((meta.u.bmu_bitmap & (1 << i))) {
int t = 0;
if (nswdev)
t = (blk + i) / dmmax % nswdev;
if (t < ti)
--swap_ary[t].ksw_used;
if (ti >= 0)
--swap_ary[ti].ksw_used;
}
}
}
} else if (meta.u.bmu_avail == radix) {
/*
* Meta node if all free
*/
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s(0x%06x,%d) Submap ALL-FREE {\n",
TABME,
blk,
radix,
(int)meta.u.bmu_avail,
meta.bm_bighint
);
}
/*
* Note: both dmmax and radix are powers of 2. However, dmmax
* may be larger then radix so use a smaller increment if
* necessary.
*/
{
int t;
int tinc = dmmax;
while (tinc > radix)
tinc >>= 1;
for (t = blk; t < blk + radix; t += tinc) {
int u = (nswdev) ? (t / dmmax % nswdev) : 0;
if (u < ti)
swap_ary[u].ksw_used -= tinc;
if (ti >= 0)
swap_ary[ti].ksw_used -= tinc;
}
}
} else if (meta.u.bmu_avail == 0) {
/*
* Meta node if all used
*/
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s(0x%06x,%d) Submap ALL-ALLOCATED\n",
TABME,
blk,
radix,
(int)meta.u.bmu_avail,
meta.bm_bighint
);
}
} else {
/*
* Meta node if not all free
*/
int i;
int next_skip;
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s(0x%06x,%d) Submap avail=%d big=%d {\n",
TABME,
blk,
radix,
(int)meta.u.bmu_avail,
meta.bm_bighint
);
}
radix >>= BLIST_META_RADIX_SHIFT;
next_skip = skip >> BLIST_META_RADIX_SHIFT;
for (i = 1; i <= skip; i += next_skip) {
int r;
daddr_t vcount = (count > radix) ? radix : count;
r = scanradix(
&scan[i],
blk,
radix,
next_skip - 1,
vcount,
kd,
dmmax,
nswdev,
swap_ary,
swap_max,
tab + 4,
flags
);
if (r < 0)
break;
blk += radix;
}
if (flags & SWIF_DUMP_TREE) {
printf("%*.*s}\n", TABME);
}
}
return(0);
}
static void
getswapinfo_radix(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags)
{
struct blist *swapblist = NULL;
struct blist blcopy = { 0 };
KGET(NL_SWAPBLIST, swapblist);
if (swapblist == NULL) {
if (flags & SWIF_DUMP_TREE)
printf("radix tree: NULL - no swap in system\n");
return;
}
KGET2(swapblist, &blcopy, sizeof(blcopy), "*swapblist");
if (flags & SWIF_DUMP_TREE) {
printf("radix tree: %d/%d/%d blocks, %dK wired\n",
blcopy.bl_free,
blcopy.bl_blocks,
blcopy.bl_radix,
(blcopy.bl_rootblks * sizeof(blmeta_t) + 1023)/
1024
);
}
scanradix(
blcopy.bl_root,
0,
blcopy.bl_radix,
blcopy.bl_skip,
blcopy.bl_rootblks,
kd,
dmmax,
nswdev,
swap_ary,
swap_max,
0,
flags
);
}