[src/trunk]: src/sys/kern - Pad kmem cache names with zeros so vmstat -m and ...

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

details:   https://anonhg.NetBSD.org/src/rev/0da9cb483a1f
branches:  trunk
changeset: 1006722:0da9cb483a1f
user:      ad <ad%NetBSD.org@localhost>
date:      Sat Jan 25 15:08:40 2020 +0000

description:
- Pad kmem cache names with zeros so vmstat -m and -C are readable.
- Exclude caches with size not a factor or multiple of the coherency unit.

Proposed on tech-kern@.  Also:

Reported-by: syzbot+c024c50570cccac51532%syzkaller.appspotmail.com@localhost

diffstat:

 sys/kern/subr_kmem.c |  86 +++++++++++++++++++++++++++------------------------
 1 files changed, 46 insertions(+), 40 deletions(-)

diffs (124 lines):

diff -r df632647154c -r 0da9cb483a1f sys/kern/subr_kmem.c
--- a/sys/kern/subr_kmem.c      Sat Jan 25 12:26:58 2020 +0000
+++ b/sys/kern/subr_kmem.c      Sat Jan 25 15:08:40 2020 +0000
@@ -1,7 +1,7 @@
-/*     $NetBSD: subr_kmem.c,v 1.77 2019/11/14 16:23:52 maxv Exp $      */
+/*     $NetBSD: subr_kmem.c,v 1.78 2020/01/25 15:08:40 ad Exp $        */
 
 /*
- * Copyright (c) 2009-2015 The NetBSD Foundation, Inc.
+ * Copyright (c) 2009-2020 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.77 2019/11/14 16:23:52 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.78 2020/01/25 15:08:40 ad Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_kmem.h"
@@ -105,35 +105,35 @@
 };
 
 static const struct kmem_cache_info kmem_cache_sizes[] = {
-       {  8, "kmem-8" },
-       { 16, "kmem-16" },
-       { 24, "kmem-24" },
-       { 32, "kmem-32" },
-       { 40, "kmem-40" },
-       { 48, "kmem-48" },
-       { 56, "kmem-56" },
-       { 64, "kmem-64" },
-       { 80, "kmem-80" },
-       { 96, "kmem-96" },
-       { 112, "kmem-112" },
-       { 128, "kmem-128" },
-       { 160, "kmem-160" },
-       { 192, "kmem-192" },
-       { 224, "kmem-224" },
-       { 256, "kmem-256" },
-       { 320, "kmem-320" },
-       { 384, "kmem-384" },
-       { 448, "kmem-448" },
-       { 512, "kmem-512" },
-       { 768, "kmem-768" },
-       { 1024, "kmem-1024" },
+       {  8, "kmem-00008" },
+       { 16, "kmem-00016" },
+       { 24, "kmem-00024" },
+       { 32, "kmem-00032" },
+       { 40, "kmem-00040" },
+       { 48, "kmem-00048" },
+       { 56, "kmem-00056" },
+       { 64, "kmem-00064" },
+       { 80, "kmem-00080" },
+       { 96, "kmem-00096" },
+       { 112, "kmem-00112" },
+       { 128, "kmem-00128" },
+       { 160, "kmem-00160" },
+       { 192, "kmem-00192" },
+       { 224, "kmem-00224" },
+       { 256, "kmem-00256" },
+       { 320, "kmem-00320" },
+       { 384, "kmem-00384" },
+       { 448, "kmem-00448" },
+       { 512, "kmem-00512" },
+       { 768, "kmem-00768" },
+       { 1024, "kmem-01024" },
        { 0, NULL }
 };
 
 static const struct kmem_cache_info kmem_cache_big_sizes[] = {
-       { 2048, "kmem-2048" },
-       { 4096, "kmem-4096" },
-       { 8192, "kmem-8192" },
+       { 2048, "kmem-02048" },
+       { 4096, "kmem-04096" },
+       { 8192, "kmem-08192" },
        { 16384, "kmem-16384" },
        { 0, NULL }
 };
@@ -359,22 +359,28 @@
                pool_cache_t pc;
                size_t align;
 
-               if ((cache_size & (CACHE_LINE_SIZE - 1)) == 0)
-                       align = CACHE_LINE_SIZE;
-               else if ((cache_size & (PAGE_SIZE - 1)) == 0)
-                       align = PAGE_SIZE;
-               else
-                       align = KMEM_ALIGN;
-
-               if (cache_size < CACHE_LINE_SIZE)
-                       flags |= PR_NOTOUCH;
-
                /* check if we reached the requested size */
                if (cache_size > maxsize || cache_size > PAGE_SIZE) {
                        break;
                }
-               if ((cache_size >> shift) > maxidx) {
-                       maxidx = cache_size >> shift;
+
+               /*
+                * Exclude caches with size not a factor or multiple of the
+                * coherency unit.
+                */
+               if (cache_size < COHERENCY_UNIT) {
+                       if (COHERENCY_UNIT % cache_size > 0) {
+                               continue;
+                       }
+                       flags |= PR_NOTOUCH;
+                       align = KMEM_ALIGN;
+               } else if ((cache_size & (PAGE_SIZE - 1)) == 0) {
+                       align = PAGE_SIZE;
+               } else {
+                       if ((cache_size % COHERENCY_UNIT) > 0) {
+                               continue;
+                       }
+                       align = COHERENCY_UNIT;
                }
 
                if ((cache_size >> shift) > maxidx) {