Bring "netstat -m" output up to speed with the kernel

The kernel no longer sets watermarks on cluster pools rendering
"max" values useless. Instead, there's now a global limit on how
much memory all cluster pools combined together can allocate from
the system. The limit is set to kern.maxclusters number of 2Kb
increments which allows us to display current, peak and maximum
total memory used by the network.

OK claudio, millert

1 files changed, 20 insertions, 13 deletions

diff --git a/usr.bin/netstat/mbuf.c b/usr.bin/netstat/mbuf.c
index f7970a57c32..13ac8e78c11 100644
--- a/usr.bin/netstat/mbuf.c
+++ b/usr.bin/netstat/mbuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mbuf.c,v 1.39 2017/02/04 13:17:08 jsg Exp $	*/
+/*	$OpenBSD: mbuf.c,v 1.40 2017/10/28 15:25:20 mikeb Exp $	*/
 /*	$NetBSD: mbuf.c,v 1.9 1996/05/07 02:55:03 thorpej Exp $	*/
 
 /*
@@ -87,9 +87,8 @@ bool seen[256];			/* "have we seen this type yet?" */
 void
 mbpr(void)
 {
-	unsigned long totmem, totused, totmbufs;
-	int totpct;
-	int i, mib[4], npools;
+	unsigned long totmem, totpeak, totmbufs;
+	int i, maxclusters, mib[4], npools;
 	struct kinfo_pool pool;
 	struct mbtypes *mp;
 	size_t size;
@@ -102,6 +101,16 @@ mbpr(void)
 	}
 
 	mib[0] = CTL_KERN;
+	mib[1] = KERN_MAXCLUSTERS;
+	size = sizeof(maxclusters);
+
+	if (sysctl(mib, 2, &maxclusters, &size, NULL, 0) < 0) {
+		printf("Can't retrieve value of maxclusters from the "
+		    "kernel: %s\n",  strerror(errno));
+		return;
+	}
+
+	mib[0] = CTL_KERN;
 	mib[1] = KERN_MBSTAT;
 	size = sizeof(mbstat);
 
@@ -176,23 +185,21 @@ mbpr(void)
 			    plural(mbstat.m_mtypes[i]), i);
 		}
 	totmem = (mbpool.pr_npages * mbpool.pr_pgsize);
-	totused = mbpool.pr_nout * mbpool.pr_size;
+	totpeak = mbpool.pr_hiwat * mbpool.pr_pgsize;
 	for (i = 0; i < mclp; i++) {
-		printf("%u/%lu/%lu mbuf %d byte clusters in use"
-		    " (current/peak/max)\n",
+		printf("%u/%lu mbuf %d byte clusters in use"
+		    " (current/peak)\n",
 		    mclpools[i].pr_nout,
 		    (unsigned long)
 			(mclpools[i].pr_hiwat * mclpools[i].pr_itemsperpage),
-		    (unsigned long)
-			(mclpools[i].pr_maxpages * mclpools[i].pr_itemsperpage),
 		    mclpools[i].pr_size);
 		totmem += (mclpools[i].pr_npages * mclpools[i].pr_pgsize);
-		totused += mclpools[i].pr_nout * mclpools[i].pr_size;
+		totpeak += mclpools[i].pr_hiwat * mclpools[i].pr_pgsize;
 	}
 
-	totpct = (totmem == 0) ? 0 : (totused/(totmem / 100));
-	printf("%lu Kbytes allocated to network (%d%% in use)\n",
-	    totmem / 1024, totpct);
+	printf("%lu/%lu/%lu Kbytes allocated to network "
+	    "(current/peak/max)\n", totmem / 1024, totpeak / 1024,
+	    (unsigned long)(maxclusters * MCLBYTES) / 1024);
 	printf("%lu requests for memory denied\n", mbstat.m_drops);
 	printf("%lu requests for memory delayed\n", mbstat.m_wait);
 	printf("%lu calls to protocol drain routines\n", mbstat.m_drain);