[src/trunk]: src/usr.bin/vmstat Use kernel sysctl hashstat collection instead...

[simonb <simonb%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e8b8ceda6bee
branches:  trunk
changeset: 954195:e8b8ceda6bee
user:      simonb <simonb%NetBSD.org@localhost>
date:      Thu Apr 01 06:23:14 2021 +0000

description:
Use kernel sysctl hashstat collection instead of kmem grovelling
directly.  Also GC a few old hash nlist entries that no longer exist.

diffstat:

 usr.bin/vmstat/vmstat.c |  106 ++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 86 insertions(+), 20 deletions(-)

diffs (170 lines):

diff -r 4244599e8be1 -r e8b8ceda6bee usr.bin/vmstat/vmstat.c
--- a/usr.bin/vmstat/vmstat.c   Thu Apr 01 06:22:09 2021 +0000
+++ b/usr.bin/vmstat/vmstat.c   Thu Apr 01 06:23:14 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: vmstat.c,v 1.244 2021/04/01 05:33:50 simonb Exp $ */
+/* $NetBSD: vmstat.c,v 1.245 2021/04/01 06:23:14 simonb Exp $ */
 
 /*-
  * Copyright (c) 1998, 2000, 2001, 2007, 2019, 2020
@@ -71,7 +71,7 @@
 #if 0
 static char sccsid[] = "@(#)vmstat.c   8.2 (Berkeley) 3/1/95";
 #else
-__RCSID("$NetBSD: vmstat.c,v 1.244 2021/04/01 05:33:50 simonb Exp $");
+__RCSID("$NetBSD: vmstat.c,v 1.245 2021/04/01 06:23:14 simonb Exp $");
 #endif
 #endif /* not lint */
 
@@ -113,6 +113,7 @@
 #include <nfs/nfsproto.h>
 #include <nfs/nfsnode.h>
 
+#include <assert.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
@@ -207,31 +208,23 @@
  */
 struct nlist hashnl[] =
 {
-#define        X_NFSNODE       0
-       { .n_name = "_nfsnodehash" },
-#define        X_NFSNODETBL    1
-       { .n_name = "_nfsnodehashtbl" },
-#define        X_IHASH         2
-       { .n_name = "_ihash" },
-#define        X_IHASHTBL      3
-       { .n_name = "_ihashtbl" },
-#define        X_BUFHASH       4
+#define        X_BUFHASH       0
        { .n_name = "_bufhash" },
-#define        X_BUFHASHTBL    5
+#define        X_BUFHASHTBL    1
        { .n_name = "_bufhashtbl" },
-#define        X_UIHASH        6
+#define        X_UIHASH        2
        { .n_name = "_uihash" },
-#define        X_UIHASHTBL     7
+#define        X_UIHASHTBL     3
        { .n_name = "_uihashtbl" },
-#define        X_IFADDRHASH    8
+#define        X_IFADDRHASH    4
        { .n_name = "_in_ifaddrhash" },
-#define        X_IFADDRHASHTBL 9
+#define        X_IFADDRHASHTBL 5
        { .n_name = "_in_ifaddrhashtbl" },
-#define        X_VCACHEHASH    10
+#define        X_VCACHEHASH    6
        { .n_name = "_vcache_hashmask" },
-#define        X_VCACHETBL     11
+#define        X_VCACHETBL     7
        { .n_name = "_vcache_hashtab" },
-#define X_HASHNL_SIZE  12      /* must be last */
+#define X_HASHNL_SIZE  8       /* must be last */
        { .n_name = NULL },
 };
 
@@ -300,6 +293,7 @@
 void   drvstats(int *);
 void   doevcnt(int verbose, int type);
 void   dohashstat(int, int, const char *);
+void   dohashstat_sysctl(int, int, const char *);
 void   dointr(int verbose);
 void   dopool(int, int);
 void   dopoolcache(int);
@@ -1925,6 +1919,9 @@
        u_long  hashsize, i;
        int     used, items, chain, maxchain;
 
+       if (memf == NULL)
+               return dohashstat_sysctl(verbose, todo, hashname);
+
        hashbuf = NULL;
        hashbufsize = 0;
 
@@ -2057,6 +2054,75 @@
        }
 }
 
+void
+dohashstat_sysctl(int verbose, int todo, const char *hashname)
+{
+       struct hashstat_sysctl hash, *data, *hs;
+       int mib[3];
+       int error;
+       size_t i, len, miblen;
+
+
+       miblen = __arraycount(mib);
+       error = sysctlnametomib("kern.hashstat", mib, &miblen);
+       if (error)
+               err(EXIT_FAILURE, "nametomib kern.hashstat failed");
+       assert(miblen < 3);
+
+       if (todo & HASHLIST) {
+               mib[miblen] = CTL_DESCRIBE;
+               miblen++;
+       };
+
+       if (hashname) {
+               mib[miblen] = CTL_QUERY;
+               miblen++;
+               memset(&hash, 0, sizeof(hash));
+               strlcpy(hash.hash_name, hashname, sizeof(hash.hash_name));
+               len = sizeof(hash);
+               error = sysctl(mib, miblen, &hash, &len, &hash, len);
+               if (error == ENOENT) {
+                       err(1, "hash '%s' not found", hashname);
+                       return;
+               } else if (error) {
+                       err(1, "sysctl kern.hashstat query failed");
+                       return;
+               }
+
+               data = &hash;
+               len = 1;
+       } else {
+               data = asysctl(mib, miblen, &len);
+               if (data == NULL)
+                       err(1, "failed to read kern.hashstat");
+               len /= sizeof(*data);
+       }
+
+       if (todo & HASHLIST) {
+               printf("Supported hashes:\n");
+               for (i = 0, hs = data; i < len; i++, hs++) {
+                       printf("\t%-16s%s\n", hs->hash_name, hs->hash_desc);
+               }
+       } else {
+               printf("%-16s %8s %8s %8s %8s %8s %8s\n"
+                   "%-16s %8s %8s %8s %8s %8s %8s\n",
+                   "", "total", "used", "util", "num", "average", "maximum",
+                   "hash table", "buckets", "buckets", "%", "items", "chain",
+                   "chain");
+               for (i = 0, hs = data; i < len; i++, hs++) {
+                       printf("%-16s %8"PRId64" %8"PRId64" %8.2f %8"PRId64
+                           " %8.2f %8"PRId64"\n",
+                           hs->hash_name, hs->hash_size, hs->hash_used,
+                           hs->hash_used * 100.0 / hs->hash_size, hs->hash_items,
+                           hs->hash_used ? (double)hs->hash_items / hs->hash_used : 0.0,
+                           hs->hash_maxchain);
+               }
+       }
+
+       if (!hashname && (data != NULL))
+               free(data);
+}
+
 /*
  * kreadc like kread but returns 1 if successful, 0 otherwise
  */
@@ -2254,7 +2320,7 @@
                        warnx("kernel history is not compiled into the kernel.");
                        return;
                } else
-                       err(EXIT_FAILURE, "nametomib failed");
+                       err(EXIT_FAILURE, "nametomib kern.hist failed");
        }
  
        /* get the list of nodenames below kern.hist */