[src/trunk]: src/sys/kern kmem(9): Tweak branch predictions in fast paths.

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

details:   https://anonhg.NetBSD.org/src/rev/8d898293dd54
branches:  trunk
changeset: 374185:8d898293dd54
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Apr 09 08:50:20 2023 +0000

description:
kmem(9): Tweak branch predictions in fast paths.

diffstat:

 sys/kern/subr_kmem.c |  18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diffs (62 lines):

diff -r f156f4c784f9 -r 8d898293dd54 sys/kern/subr_kmem.c
--- a/sys/kern/subr_kmem.c      Sun Apr 09 08:28:24 2023 +0000
+++ b/sys/kern/subr_kmem.c      Sun Apr 09 08:50:20 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_kmem.c,v 1.87 2022/05/30 23:36:26 mrg Exp $       */
+/*     $NetBSD: subr_kmem.c,v 1.88 2023/04/09 08:50:20 riastradh Exp $ */
 
 /*
  * Copyright (c) 2009-2020 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.87 2022/05/30 23:36:26 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.88 2023/04/09 08:50:20 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_kmem.h"
@@ -346,7 +346,7 @@ kmem_intr_zalloc(size_t size, km_flag_t 
        void *p;
 
        p = kmem_intr_alloc(size, kmflags);
-       if (p != NULL) {
+       if (__predict_true(p != NULL)) {
                memset(p, 0, size);
        }
        return p;
@@ -406,8 +406,9 @@ kmem_alloc(size_t size, km_flag_t kmflag
 {
        void *v;
 
-       KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()),
-           "kmem(9) should not be used from the interrupt context");
+       KASSERT(!cpu_intr_p());
+       KASSERT(!cpu_softintr_p());
+
        v = kmem_intr_alloc(size, kmflags);
        if (__predict_true(v != NULL)) {
                kmsan_mark(v, size, KMSAN_STATE_UNINIT);
@@ -426,8 +427,9 @@ kmem_zalloc(size_t size, km_flag_t kmfla
 {
        void *v;
 
-       KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()),
-           "kmem(9) should not be used from the interrupt context");
+       KASSERT(!cpu_intr_p());
+       KASSERT(!cpu_softintr_p());
+
        v = kmem_intr_zalloc(size, kmflags);
        KASSERT(v || (kmflags & KM_NOSLEEP) != 0);
        return v;
@@ -440,8 +442,10 @@ kmem_zalloc(size_t size, km_flag_t kmfla
 void
 kmem_free(void *p, size_t size)
 {
+
        KASSERT(!cpu_intr_p());
        KASSERT(!cpu_softintr_p());
+
        kmem_intr_free(p, size);
        kmsan_mark(p, size, KMSAN_STATE_INITED);
 }