[src/trunk]: src/usr.sbin/lockstat Make makelists() a little bit faster.

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

details:   https://anonhg.NetBSD.org/src/rev/4c5cdbcb25d0
branches:  trunk
changeset: 850438:4c5cdbcb25d0
user:      ad <ad%NetBSD.org@localhost>
date:      Sat Apr 04 16:40:50 2020 +0000

description:
Make makelists() a little bit faster.

diffstat:

 usr.sbin/lockstat/main.c |  22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)

diffs (79 lines):

diff -r 83bf42b54e19 -r 4c5cdbcb25d0 usr.sbin/lockstat/main.c
--- a/usr.sbin/lockstat/main.c  Sat Apr 04 16:25:17 2020 +0000
+++ b/usr.sbin/lockstat/main.c  Sat Apr 04 16:40:50 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: main.c,v 1.19 2013/03/06 11:49:06 yamt Exp $   */
+/*     $NetBSD: main.c,v 1.20 2020/04/04 16:40:50 ad Exp $     */
 
 /*-
  * Copyright (c) 2006, 2007, 2009 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: main.c,v 1.19 2013/03/06 11:49:06 yamt Exp $");
+__RCSID("$NetBSD: main.c,v 1.20 2020/04/04 16:40:50 ad Exp $");
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -70,9 +70,12 @@
 typedef struct lock_head locklist_t;
 TAILQ_HEAD(buf_head, lsbuf);
 typedef struct buf_head buflist_t;
+SLIST_HEAD(bucket, lockstruct);
+typedef struct bucket bucket_t;
 
 typedef struct lockstruct {
        TAILQ_ENTRY(lockstruct) chain;
+       SLIST_ENTRY(lockstruct) bucket;
        buflist_t               bufs;
        buflist_t               tosort;
        uintptr_t               lock;
@@ -128,6 +131,9 @@
 static locklist_t      locklist;
 static locklist_t      freelist;
 static locklist_t      sortlist;
+static bucket_t                bucket[256];
+
+#define        HASH(a)         (&bucket[((a) >> 6) & (__arraycount(bucket) - 1)])
 
 static lsbuf_t         *bufs;
 static lsdisable_t     ld;
@@ -604,14 +610,16 @@
 {
        lsbuf_t *lb, *lb2, *max;
        lock_t *l, *l2;
+       bucket_t *bp;
        int type;
+       size_t i;
 
        /*
         * Recycle lock_t structures from the last run.
         */
-       while ((l = TAILQ_FIRST(&locklist)) != NULL) {
-               TAILQ_REMOVE(&locklist, l, chain);
-               TAILQ_INSERT_HEAD(&freelist, l, chain);
+       TAILQ_CONCAT(&freelist, &locklist, chain);
+       for (i = 0; i < __arraycount(bucket); i++) {
+               SLIST_INIT(&bucket[i]);
        }
 
        type = mask & LB_LOCK_MASK;
@@ -626,7 +634,8 @@
                 * Look for a record descibing this lock, and allocate a
                 * new one if needed.
                 */
-               TAILQ_FOREACH(l, &sortlist, chain) {
+               bp = HASH(lb->lb_lock);
+               SLIST_FOREACH(l, bp, bucket) {
                        if (l->lock == lb->lb_lock)
                                break;
                }
@@ -643,6 +652,7 @@
                        TAILQ_INIT(&l->tosort);
                        TAILQ_INIT(&l->bufs);
                        TAILQ_INSERT_TAIL(&sortlist, l, chain);
+                       SLIST_INSERT_HEAD(bp, l, bucket);
                }
 
                /*