[src/trunk]: src/sys/kern add explanatory comment in bremfree:

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

details:   https://anonhg.NetBSD.org/src/rev/c58412daf6c7
branches:  trunk
changeset: 555856:c58412daf6c7
user:      dbj <dbj%NetBSD.org@localhost>
date:      Tue Dec 02 03:36:33 2003 +0000

description:
add explanatory comment in bremfree:
 We break the TAILQ abstraction in order to efficiently remove a
 buffer from its freelist without having to know exactly which
 freelist it is on.

diffstat:

 sys/kern/vfs_bio.c |  8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diffs (29 lines):

diff -r 85419d9ec8e3 -r c58412daf6c7 sys/kern/vfs_bio.c
--- a/sys/kern/vfs_bio.c        Tue Dec 02 03:01:19 2003 +0000
+++ b/sys/kern/vfs_bio.c        Tue Dec 02 03:36:33 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_bio.c,v 1.97 2003/11/08 04:22:35 dbj Exp $ */
+/*     $NetBSD: vfs_bio.c,v 1.98 2003/12/02 03:36:33 dbj Exp $ */
 
 /*-
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -80,7 +80,7 @@
 #include "opt_softdep.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.97 2003/11/08 04:22:35 dbj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.98 2003/12/02 03:36:33 dbj Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -170,6 +170,10 @@
         * it is needed (e.g. to reset the tail pointer).
         *
         * NB: This makes an assumption about how tailq's are implemented.
+        *
+        * We break the TAILQ abstraction in order to efficiently remove a
+        * buffer from its freelist without having to know exactly which
+        * freelist it is on.
         */
        if (TAILQ_NEXT(bp, b_freelist) == NULL) {
                for (dp = bufqueues; dp < &bufqueues[BQUEUES]; dp++)