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From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: How to see the swap disk usage?
Date: 10 Jan 1997 23:55:29 GMT
Organization: Private BSD site, Dresden
Lines: 293
Message-ID: <5b6kth$q9r@uriah.heep.sax.de>
References: <5b2ckv$7h@mc5.mcnet.ch>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
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Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:33960
Benoit.Rossier@mcnet.ch (Benoit Rossier) wrote:
> How can I see the swap disk usage?
>
> I have tried the command systat -swap but it does not show the swap.
Too bad that there are so many different sources trying to do the
same, but with minor differences... This one was:
----------------------------
revision 1.2
date: 1994/10/09 07:37:18; author: davidg; state: Exp; lines: +7 -1
#if 0'd out the meat of the swap code until I get a chance to rewrite it.
----------------------------
...so all versions after FreeBSD 2.0 didn't have the swap display.
Apparently, nobody noticed it yet. :)
Here's a patch, but i think this one will only work for >= 2.2
systems, since the swap structure in the kernel has been changed since
2.1.x, from a plain map to a list. Basically, the meat has been taken
from pstat (aka. swapinfo).
Index: systat/swap.c
===================================================================
RCS file: /home/ncvs/src/usr.bin/systat/swap.c,v
retrieving revision 1.3
diff -u -u -r1.3 swap.c
--- swap.c 1995/05/30 06:34:28 1.3
+++ swap.c 1997/01/10 23:31:09
@@ -62,37 +62,34 @@
kvm_t *kd;
struct nlist syms[] = {
- { "_swapmap" }, /* list of free swap areas */
-#define VM_SWAPMAP 0
- { "_nswapmap" },/* size of the swap map */
-#define VM_NSWAPMAP 1
+ { "_swaplist" },/* list of free swap areas */
+#define VM_SWAPLIST 0
{ "_swdevt" }, /* list of swap devices and sizes */
-#define VM_SWDEVT 2
+#define VM_SWDEVT 1
{ "_nswap" }, /* size of largest swap device */
-#define VM_NSWAP 3
+#define VM_NSWAP 2
{ "_nswdev" }, /* number of swap devices */
-#define VM_NSWDEV 4
+#define VM_NSWDEV 3
{ "_dmmax" }, /* maximum size of a swap block */
-#define VM_DMMAX 5
+#define VM_DMMAX 4
0
};
-static int nswap, nswdev, dmmax, nswapmap;
+static int nswap, nswdev, dmmax;
static struct swdevt *sw;
static long *perdev, blocksize;
-static struct map *swapmap, *kswapmap;
-static struct mapent *mp;
static int nfree, hlen;
+static struct rlisthdr swaplist;
#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(syms[idx].n_value, p, s, msg)
-#define KGET2(addr, p, s, msg) \
+ KGET1(idx, &var, sizeof(var), SVAR(var), (0))
+#define KGET1(idx, p, s, msg, rv) \
+ KGET2(syms[idx].n_value, p, s, msg, rv)
+#define KGET2(addr, p, s, msg, rv) \
if (kvm_read(kd, addr, p, s) != s) { \
error("cannot read %s: %s", msg, kvm_geterr(kd)); \
- return (0); \
+ return rv; \
}
WINDOW *
@@ -112,13 +109,19 @@
delwin(w);
}
+/*
+ * The meat of all the swap stuff is stolen from pstat(8)'s
+ * swapmode(), which is based on a program called swapinfo written by
+ * Kevin Lahey <kml@rokkaku.atl.ga.us>.
+ */
+
initswap()
{
int i;
char msgbuf[BUFSIZ];
static int once = 0;
+ u_long ptr;
-#if 0
if (once)
return (1);
if (kvm_nlist(kd, syms)) {
@@ -135,71 +138,61 @@
KGET(VM_NSWAP, nswap);
KGET(VM_NSWDEV, nswdev);
KGET(VM_DMMAX, dmmax);
- KGET(VM_NSWAPMAP, nswapmap);
- KGET(VM_SWAPMAP, kswapmap); /* kernel `swapmap' is a pointer */
if ((sw = malloc(nswdev * sizeof(*sw))) == NULL ||
- (perdev = malloc(nswdev * sizeof(*perdev))) == NULL ||
- (mp = malloc(nswapmap * sizeof(*mp))) == NULL) {
- error("swap malloc");
- return (0);
- }
- KGET1(VM_SWDEVT, sw, nswdev * sizeof(*sw), "swdevt");
+ (perdev = malloc(nswdev * sizeof(*perdev))) == NULL)
+ err(1, "malloc");
+ KGET1(VM_SWDEVT, &ptr, sizeof ptr, "swdevt", (0));
+ KGET2(ptr, sw, nswdev * sizeof(*sw), "*swdevt", (0));
once = 1;
return (1);
-#else
- return (0);
-#endif
}
void
fetchswap()
{
- int s, e, i;
-
-#if 0
- s = nswapmap * sizeof(*mp);
- if (kvm_read(kd, (long)kswapmap, mp, s) != s)
- error("cannot read swapmap: %s", kvm_geterr(kd));
-
- /* first entry in map is `struct map'; rest are mapent's */
- swapmap = (struct map *)mp;
- if (nswapmap != swapmap->m_limit - (struct mapent *)kswapmap)
- error("panic: swap: nswapmap goof");
+ struct rlist head;
+ struct rlist *swapptr;
- /*
- * Count up swap space.
- */
+ /* Count up swap space. */
nfree = 0;
- bzero(perdev, nswdev * sizeof(*perdev));
- for (mp++; mp->m_addr != 0; mp++) {
- s = mp->m_addr; /* start of swap region */
- e = mp->m_addr + mp->m_size; /* end of region */
- nfree += mp->m_size;
+ memset(perdev, 0, nswdev * sizeof(*perdev));
+ KGET1(VM_SWAPLIST, &swaplist, sizeof swaplist, "swaplist", /* none */);
+ swapptr = swaplist.rlh_list;
+ while (swapptr) {
+ int top, bottom, next_block;
+
+ KGET2((unsigned long)swapptr, &head,
+ sizeof(struct rlist), "swapptr", /* none */);
+
+ top = head.rl_end;
+ bottom = head.rl_start;
+
+ nfree += top - bottom + 1;
/*
* Swap space is split up among the configured disks.
- * The first dmmax blocks of swap space some from the
- * first disk, the next dmmax blocks from the next,
- * and so on. The list of free space joins adjacent
- * free blocks, ignoring device boundries. If we want
- * to keep track of this information per device, we'll
- * just have to extract it ourselves.
+ *
+ * For interleaved swap devices, the first dmmax blocks
+ * of swap space some from the first disk, the next dmmax
+ * blocks from the next, and so on up to nswap blocks.
+ *
+ * The list of free space joins adjacent free blocks,
+ * ignoring device boundries. If we want to keep track
+ * of this information per device, we'll just have to
+ * extract it ourselves.
*/
-
- /* calculate first device on which this falls */
- i = (s / dmmax) % nswdev;
- while (s < e) { /* XXX this is inefficient */
- int bound = roundup(s + 1, dmmax);
-
- if (bound > e)
- bound = e;
- perdev[i] += bound - s;
- if (++i >= nswdev)
- i = 0;
- s = bound;
+ while (top / dmmax != bottom / dmmax) {
+ next_block = ((bottom + dmmax) / dmmax);
+ perdev[(bottom / dmmax) % nswdev] +=
+ next_block * dmmax - bottom;
+ bottom = next_block * dmmax;
}
+ perdev[(bottom / dmmax) % nswdev] +=
+ top - bottom + 1;
+
+ swapptr = head.rl_next;
}
-#endif
+
}
void
@@ -211,36 +204,42 @@
row = 0;
wmove(wnd, row, 0); wclrtobot(wnd);
header = getbsize(&hlen, &blocksize);
- mvwprintw(wnd, row++, 0, "%-5s%*s%9s %55s",
+ mvwprintw(wnd, row++, 0, "%-5s%*s%9s %55s",
"Disk", hlen, header, "Used",
- "/0% /10% /20% /30% /40% /50% /60% /70% /80% /90% /100%");
+ "/0% /10% /20% /30% /40% /50% /60% /70% /80% /90% /100");
for (i = 0; i < nswdev; i++) {
+ if (!sw[i].sw_freed)
+ continue;
mvwprintw(wnd, i + 1, 0, "%-5s",
- devname(sw[i].sw_dev, S_IFBLK));
+ sw[i].sw_dev != NODEV?
+ devname(sw[i].sw_dev, S_IFBLK): "[NFS]");
}
}
void
showswap()
{
- int col, row, div, i, j, avail, npfree, used, xsize, xfree;
+ int col, row, div, i, j, k, avail, npfree, used, xsize, xfree;
div = blocksize / 512;
avail = npfree = 0;
- for (i = 0; i < nswdev; i++) {
- col = 5;
- mvwprintw(wnd, i + 1, col, "%*d", hlen, sw[i].sw_nblks / div);
- col += hlen;
+ for (i = k = 0; i < nswdev; i++) {
/*
* Don't report statistics for partitions which have not
* yet been activated via swapon(8).
*/
- if (!sw[i].sw_freed) {
- mvwprintw(wnd, i + 1, col + 8,
- "0 *** not available for swapping ***");
+ if (!sw[i].sw_freed)
continue;
- }
- xsize = sw[i].sw_nblks;
+
+ col = 5;
+ mvwprintw(wnd, i + 1, col, "%*d", hlen, sw[i].sw_nblks / div);
+ col += hlen;
+
+ /*
+ * The first dmmax is never allocated to avoid trashing of
+ * disklabels
+ */
+ xsize = sw[i].sw_nblks - dmmax;
xfree = perdev[i];
used = xsize - xfree;
mvwprintw(wnd, i + 1, col, "%9d ", used / div);
@@ -248,6 +247,7 @@
waddch(wnd, 'X');
npfree++;
avail += xsize;
+ k++;
}
/*
* If only one partition has been set up via swapon(8), we don't
@@ -255,7 +255,7 @@
*/
if (npfree > 1) {
used = avail - nfree;
- mvwprintw(wnd, i + 1, 0, "%-5s%*d%9d ",
+ mvwprintw(wnd, k + 1, 0, "%-5s%*d%9d ",
"Total", hlen, avail / div, used / div);
for (j = (100 * used / avail + 1) / 2; j > 0; j--)
waddch(wnd, 'X');
--
cheers, J"org
joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)