[src/trunk]: src/sys/kern PR_NOTOUCH:

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

details:   https://anonhg.NetBSD.org/src/rev/1dbc2f0b7f4e
branches:  trunk
changeset: 572391:1dbc2f0b7f4e
user:      yamt <yamt%NetBSD.org@localhost>
date:      Sat Jan 01 21:09:56 2005 +0000

description:
PR_NOTOUCH:
- use uint8_t instead of uint16_t for freelist index.
- set ph_off only if PR_NOTOUCH.
- comment.

diffstat:

 sys/kern/subr_pool.c |  35 ++++++++++++++++++++++-------------
 1 files changed, 22 insertions(+), 13 deletions(-)

diffs (108 lines):

diff -r f19bf4adb40a -r 1dbc2f0b7f4e sys/kern/subr_pool.c
--- a/sys/kern/subr_pool.c      Sat Jan 01 21:08:02 2005 +0000
+++ b/sys/kern/subr_pool.c      Sat Jan 01 21:09:56 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_pool.c,v 1.98 2005/01/01 21:08:02 yamt Exp $      */
+/*     $NetBSD: subr_pool.c,v 1.99 2005/01/01 21:09:56 yamt Exp $      */
 
 /*-
  * Copyright (c) 1997, 1999, 2000 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.98 2005/01/01 21:08:02 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.99 2005/01/01 21:09:56 yamt Exp $");
 
 #include "opt_pool.h"
 #include "opt_poollog.h"
@@ -99,6 +99,8 @@
 /* This spin lock protects both pool_head and drainpp. */
 struct simplelock pool_head_slock = SIMPLELOCK_INITIALIZER;
 
+typedef uint8_t pool_item_freelist_t;
+
 struct pool_item_header {
        /* Page headers */
        LIST_ENTRY(pool_item_header)
@@ -117,8 +119,12 @@
                struct {
                        uint16_t
                                phu_off;        /* start offset in page */
-                       uint16_t
+                       pool_item_freelist_t
                                phu_firstfree;  /* first free item */
+                       /*
+                        * XXX it might be better to use
+                        * a simple bitmap and ffs(3)
+                        */
                } phu_notouch;
        } ph_u;
        uint16_t                ph_nmissing;    /* # of chunks in use */
@@ -317,17 +323,18 @@
        return idx;
 }
 
-#define        PR_FREELIST_ALIGN(p)    roundup((uintptr_t)(p), sizeof(uint16_t))
-#define        PR_FREELIST(ph) ((uint16_t *)PR_FREELIST_ALIGN((ph) + 1))
-#define        PR_INDEX_USED   ((uint16_t)-1)
-#define        PR_INDEX_EOL    ((uint16_t)-2)
+#define        PR_FREELIST_ALIGN(p) \
+       roundup((uintptr_t)(p), sizeof(pool_item_freelist_t))
+#define        PR_FREELIST(ph) ((pool_item_freelist_t *)PR_FREELIST_ALIGN((ph) + 1))
+#define        PR_INDEX_USED   ((pool_item_freelist_t)-1)
+#define        PR_INDEX_EOL    ((pool_item_freelist_t)-2)
 
 static __inline void
 pr_item_notouch_put(const struct pool *pp, struct pool_item_header *ph,
     void *obj)
 {
        int idx = pr_item_notouch_index(pp, ph, obj);
-       uint16_t *freelist = PR_FREELIST(ph);
+       pool_item_freelist_t *freelist = PR_FREELIST(ph);
 
        KASSERT(freelist[idx] == PR_INDEX_USED);
        freelist[idx] = ph->ph_firstfree;
@@ -338,7 +345,7 @@
 pr_item_notouch_get(const struct pool *pp, struct pool_item_header *ph)
 {
        int idx = ph->ph_firstfree;
-       uint16_t *freelist = PR_FREELIST(ph);
+       pool_item_freelist_t *freelist = PR_FREELIST(ph);
 
        KASSERT(freelist[idx] != PR_INDEX_USED);
        ph->ph_firstfree = freelist[idx];
@@ -454,6 +461,9 @@
        size_t trysize, phsize;
        int s;
 
+       KASSERT((1UL << (CHAR_BIT * sizeof(pool_item_freelist_t))) - 2 >=
+           PHPOOL_FREELIST_NELEM(PHPOOL_MAX - 1));
+
 #ifdef POOL_DIAGNOSTIC
        /*
         * Always log if POOL_DIAGNOSTIC is defined.
@@ -654,7 +664,7 @@
                        sz = sizeof(struct pool_item_header);
                        if (nelem) {
                                sz = PR_FREELIST_ALIGN(sz)
-                                   + nelem * sizeof(uint16_t);
+                                   + nelem * sizeof(pool_item_freelist_t);
                        }
                        pool_init(&phpool[idx], sz, 0, 0, 0,
                            phpool_names[idx], &pool_allocator_meta);
@@ -1280,12 +1290,11 @@
        n = pp->pr_itemsperpage;
        pp->pr_nitems += n;
 
-       ph->ph_off = cp - storage;
-
        if (pp->pr_roflags & PR_NOTOUCH) {
-               uint16_t *freelist = PR_FREELIST(ph);
+               pool_item_freelist_t *freelist = PR_FREELIST(ph);
                int i;
 
+               ph->ph_off = cp - storage;
                ph->ph_firstfree = 0;
                for (i = 0; i < n - 1; i++)
                        freelist[i] = i + 1;