Module Name: src
Committed By: riastradh
Date: Fri Feb 24 11:02:27 UTC 2023
Modified Files:
src/sys/kern: kern_auth.c kern_descrip.c kern_mutex_obj.c kern_rwlock.c
kern_rwlock_obj.c subr_copy.c subr_ipi.c subr_pcq.c subr_pool.c
sys_futex.c uipc_mbuf.c vfs_mount.c vfs_vnode.c
Log Message:
kern: Eliminate most __HAVE_ATOMIC_AS_MEMBAR conditionals.
I'm leaving in the conditional around the legacy membar_enters
(store-before-load, store-before-store) in kern_mutex.c and in
kern_lock.c because they may still matter: store-before-load barriers
tend to be the most expensive kind, so eliding them is probably
worthwhile on x86. (It also may not matter; I just don't care to do
measurements right now, and it's a single valid and potentially
justifiable use case in the whole tree.)
However, membar_release/acquire can be mere instruction barriers on
all TSO platforms including x86, so there's no need to go out of our
way with a bad API to conditionalize them. If the procedure call
overhead is measurable we just could change them to be macros on x86
that expand into __insn_barrier.
Discussed on tech-kern:
https://mail-index.netbsd.org/tech-kern/2023/02/23/msg028729.html
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/kern/kern_auth.c
cvs rdiff -u -r1.254 -r1.255 src/sys/kern/kern_descrip.c
cvs rdiff -u -r1.10 -r1.11 src/sys/kern/kern_mutex_obj.c \
src/sys/kern/subr_ipi.c
cvs rdiff -u -r1.68 -r1.69 src/sys/kern/kern_rwlock.c
cvs rdiff -u -r1.8 -r1.9 src/sys/kern/kern_rwlock_obj.c
cvs rdiff -u -r1.16 -r1.17 src/sys/kern/subr_copy.c
cvs rdiff -u -r1.19 -r1.20 src/sys/kern/subr_pcq.c
cvs rdiff -u -r1.286 -r1.287 src/sys/kern/subr_pool.c
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/sys_futex.c
cvs rdiff -u -r1.247 -r1.248 src/sys/kern/uipc_mbuf.c
cvs rdiff -u -r1.101 -r1.102 src/sys/kern/vfs_mount.c
cvs rdiff -u -r1.148 -r1.149 src/sys/kern/vfs_vnode.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_auth.c
diff -u src/sys/kern/kern_auth.c:1.81 src/sys/kern/kern_auth.c:1.82
--- src/sys/kern/kern_auth.c:1.81 Sat Apr 9 23:38:33 2022
+++ src/sys/kern/kern_auth.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_auth.c,v 1.81 2022/04/09 23:38:33 riastradh Exp $ */
+/* $NetBSD: kern_auth.c,v 1.82 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2005, 2006 Elad Efrat <e...@netbsd.org>
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_auth.c,v 1.81 2022/04/09 23:38:33 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_auth.c,v 1.82 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -144,14 +144,10 @@ kauth_cred_free(kauth_cred_t cred)
KASSERT(cred->cr_refcnt > 0);
ASSERT_SLEEPABLE();
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
if (atomic_dec_uint_nv(&cred->cr_refcnt) > 0)
return;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
kauth_cred_hook(cred, KAUTH_CRED_FREE, NULL, NULL);
specificdata_fini(kauth_domain, &cred->cr_sd);
Index: src/sys/kern/kern_descrip.c
diff -u src/sys/kern/kern_descrip.c:1.254 src/sys/kern/kern_descrip.c:1.255
--- src/sys/kern/kern_descrip.c:1.254 Thu Feb 23 03:00:15 2023
+++ src/sys/kern/kern_descrip.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_descrip.c,v 1.254 2023/02/23 03:00:15 riastradh Exp $ */
+/* $NetBSD: kern_descrip.c,v 1.255 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.254 2023/02/23 03:00:15 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.255 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -429,9 +429,7 @@ fd_getfile(unsigned fd)
* will safely wait for references to drain.
*/
atomic_inc_uint(&ff->ff_refcnt);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
}
/*
@@ -485,9 +483,7 @@ fd_putfile(unsigned fd)
* the file after it has been freed or recycled by another
* CPU.
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
/*
* Be optimistic and start out with the assumption that no other
@@ -637,9 +633,7 @@ fd_close(unsigned fd)
* waiting for other users of the file to drain. Release
* our reference, and wake up the closer.
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_dec_uint(&ff->ff_refcnt);
cv_broadcast(&ff->ff_closing);
mutex_exit(&fdp->fd_lock);
@@ -674,13 +668,9 @@ fd_close(unsigned fd)
refcnt = --(ff->ff_refcnt);
} else {
/* Multi threaded. */
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
refcnt = atomic_dec_uint_nv(&ff->ff_refcnt);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
}
if (__predict_false(refcnt != 0)) {
/*
@@ -1566,14 +1556,10 @@ fd_free(void)
KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE);
KASSERT(fdp->fd_dtbuiltin.dt_link == NULL);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
if (atomic_dec_uint_nv(&fdp->fd_refcnt) > 0)
return;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
/*
* Close any files that the process holds open.
Index: src/sys/kern/kern_mutex_obj.c
diff -u src/sys/kern/kern_mutex_obj.c:1.10 src/sys/kern/kern_mutex_obj.c:1.11
--- src/sys/kern/kern_mutex_obj.c:1.10 Wed Oct 26 23:21:19 2022
+++ src/sys/kern/kern_mutex_obj.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_mutex_obj.c,v 1.10 2022/10/26 23:21:19 riastradh Exp $ */
+/* $NetBSD: kern_mutex_obj.c,v 1.11 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2019 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_mutex_obj.c,v 1.10 2022/10/26 23:21:19 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_mutex_obj.c,v 1.11 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -155,15 +155,11 @@ mutex_obj_free(kmutex_t *lock)
"%s: lock %p: mo->mo_refcnt (%#x) == 0",
__func__, mo, mo->mo_refcnt);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
if (atomic_dec_uint_nv(&mo->mo_refcnt) > 0) {
return false;
}
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
mutex_destroy(&mo->mo_lock);
pool_cache_put(mutex_obj_cache, mo);
return true;
Index: src/sys/kern/subr_ipi.c
diff -u src/sys/kern/subr_ipi.c:1.10 src/sys/kern/subr_ipi.c:1.11
--- src/sys/kern/subr_ipi.c:1.10 Sat Apr 9 23:51:22 2022
+++ src/sys/kern/subr_ipi.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_ipi.c,v 1.10 2022/04/09 23:51:22 riastradh Exp $ */
+/* $NetBSD: subr_ipi.c,v 1.11 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_ipi.c,v 1.10 2022/04/09 23:51:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_ipi.c,v 1.11 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -189,9 +189,7 @@ ipi_mark_pending(u_int ipi_id, struct cp
/* Mark as pending and return true if not previously marked. */
if ((atomic_load_acquire(&ci->ci_ipipend[i]) & bitm) == 0) {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_or_32(&ci->ci_ipipend[i], bitm);
return true;
}
@@ -303,9 +301,7 @@ ipi_cpu_handler(void)
continue;
}
pending = atomic_swap_32(&ci->ci_ipipend[i], 0);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
while ((bit = ffs(pending)) != 0) {
const u_int ipi_id = (i << IPI_BITW_SHIFT) | --bit;
ipi_intr_t *ipi_hdl = &ipi_intrs[ipi_id];
@@ -341,9 +337,7 @@ ipi_msg_cpu_handler(void *arg __unused)
msg->func(msg->arg);
/* Ack the request. */
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_dec_uint(&msg->_pending);
}
}
@@ -364,9 +358,7 @@ ipi_unicast(ipi_msg_t *msg, struct cpu_i
KASSERT(curcpu() != ci);
msg->_pending = 1;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
put_msg(&ipi_mboxes[id], msg);
ipi_trigger(IPI_SYNCH_ID, ci);
@@ -390,9 +382,7 @@ ipi_multicast(ipi_msg_t *msg, const kcpu
local = !!kcpuset_isset(target, cpu_index(self));
msg->_pending = kcpuset_countset(target) - local;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
for (CPU_INFO_FOREACH(cii, ci)) {
cpuid_t id;
@@ -428,9 +418,7 @@ ipi_broadcast(ipi_msg_t *msg, bool skip_
KASSERT(kpreempt_disabled());
msg->_pending = ncpu - 1;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
/* Broadcast IPIs for remote CPUs. */
for (CPU_INFO_FOREACH(cii, ci)) {
Index: src/sys/kern/kern_rwlock.c
diff -u src/sys/kern/kern_rwlock.c:1.68 src/sys/kern/kern_rwlock.c:1.69
--- src/sys/kern/kern_rwlock.c:1.68 Fri Feb 24 11:01:43 2023
+++ src/sys/kern/kern_rwlock.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_rwlock.c,v 1.68 2023/02/24 11:01:43 riastradh Exp $ */
+/* $NetBSD: kern_rwlock.c,v 1.69 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2008, 2009, 2019, 2020
@@ -45,7 +45,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_rwlock.c,v 1.68 2023/02/24 11:01:43 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_rwlock.c,v 1.69 2023/02/24 11:02:27 riastradh Exp $");
#include "opt_lockdebug.h"
@@ -100,13 +100,8 @@ do { \
/*
* Memory barriers.
*/
-#ifdef __HAVE_ATOMIC_AS_MEMBAR
-#define RW_MEMBAR_ACQUIRE()
-#define RW_MEMBAR_RELEASE()
-#else
#define RW_MEMBAR_ACQUIRE() membar_acquire()
#define RW_MEMBAR_RELEASE() membar_release()
-#endif
/*
* For platforms that do not provide stubs, or for the LOCKDEBUG case.
Index: src/sys/kern/kern_rwlock_obj.c
diff -u src/sys/kern/kern_rwlock_obj.c:1.8 src/sys/kern/kern_rwlock_obj.c:1.9
--- src/sys/kern/kern_rwlock_obj.c:1.8 Wed Oct 26 23:22:22 2022
+++ src/sys/kern/kern_rwlock_obj.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_rwlock_obj.c,v 1.8 2022/10/26 23:22:22 riastradh Exp $ */
+/* $NetBSD: kern_rwlock_obj.c,v 1.9 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009, 2019 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_rwlock_obj.c,v 1.8 2022/10/26 23:22:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_rwlock_obj.c,v 1.9 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -145,15 +145,11 @@ rw_obj_free(krwlock_t *lock)
KASSERT(ro->ro_magic == RW_OBJ_MAGIC);
KASSERT(ro->ro_refcnt > 0);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
if (atomic_dec_uint_nv(&ro->ro_refcnt) > 0) {
return false;
}
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
rw_destroy(&ro->ro_lock);
pool_cache_put(rw_obj_cache, ro);
return true;
Index: src/sys/kern/subr_copy.c
diff -u src/sys/kern/subr_copy.c:1.16 src/sys/kern/subr_copy.c:1.17
--- src/sys/kern/subr_copy.c:1.16 Sat Apr 9 23:51:09 2022
+++ src/sys/kern/subr_copy.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_copy.c,v 1.16 2022/04/09 23:51:09 riastradh Exp $ */
+/* $NetBSD: subr_copy.c,v 1.17 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008, 2019
@@ -80,7 +80,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_copy.c,v 1.16 2022/04/09 23:51:09 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_copy.c,v 1.17 2023/02/24 11:02:27 riastradh Exp $");
#define __UFETCHSTORE_PRIVATE
#define __UCAS_PRIVATE
@@ -411,9 +411,7 @@ ucas_critical_cpu_gate(void *arg __unuse
* Matches atomic_load_acquire in ucas_critical_wait -- turns
* the following atomic_dec_uint into a store-release.
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_dec_uint(&ucas_critical_pausing_cpus);
/*
Index: src/sys/kern/subr_pcq.c
diff -u src/sys/kern/subr_pcq.c:1.19 src/sys/kern/subr_pcq.c:1.20
--- src/sys/kern/subr_pcq.c:1.19 Thu Feb 23 03:03:58 2023
+++ src/sys/kern/subr_pcq.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_pcq.c,v 1.19 2023/02/23 03:03:58 riastradh Exp $ */
+/* $NetBSD: subr_pcq.c,v 1.20 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2009, 2019 The NetBSD Foundation, Inc.
@@ -118,7 +118,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pcq.c,v 1.19 2023/02/23 03:03:58 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pcq.c,v 1.20 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -273,9 +273,7 @@ pcq_get(pcq_t *pcq)
* it is at the same memory location. Yes, this is a bare
* membar_producer with no matching membar_consumer.
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_producer();
-#endif
while (__predict_false(atomic_cas_32(&pcq->pcq_pc, v, nv) != v)) {
v = atomic_load_relaxed(&pcq->pcq_pc);
pcq_split(v, &p, &c);
Index: src/sys/kern/subr_pool.c
diff -u src/sys/kern/subr_pool.c:1.286 src/sys/kern/subr_pool.c:1.287
--- src/sys/kern/subr_pool.c:1.286 Fri Feb 17 06:34:46 2023
+++ src/sys/kern/subr_pool.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_pool.c,v 1.286 2023/02/17 06:34:46 skrll Exp $ */
+/* $NetBSD: subr_pool.c,v 1.287 2023/02/24 11:02:27 riastradh Exp $ */
/*
* Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015, 2018,
@@ -33,7 +33,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.286 2023/02/17 06:34:46 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.287 2023/02/24 11:02:27 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -2558,9 +2558,7 @@ pool_pcg_get(pcg_t *volatile *head, pcg_
n = atomic_cas_ptr(head, o, __UNCONST(&pcg_dummy));
if (o == n) {
/* Fetch pointer to next item and then unlock. */
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_datadep_consumer(); /* alpha */
-#endif
n = atomic_load_relaxed(&o->pcg_next);
atomic_store_release(head, n);
break;
@@ -2592,9 +2590,7 @@ pool_pcg_trunc(pcg_t *volatile *head)
n = atomic_cas_ptr(head, o, NULL);
if (o == n) {
splx(s);
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_datadep_consumer(); /* alpha */
-#endif
return o;
}
}
@@ -2621,9 +2617,7 @@ pool_pcg_put(pcg_t *volatile *head, pcg_
continue;
}
pcg->pcg_next = o;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
n = atomic_cas_ptr(head, o, pcg);
if (o == n) {
return count != SPINLOCK_BACKOFF_MIN;
Index: src/sys/kern/sys_futex.c
diff -u src/sys/kern/sys_futex.c:1.18 src/sys/kern/sys_futex.c:1.19
--- src/sys/kern/sys_futex.c:1.18 Thu Apr 21 12:05:13 2022
+++ src/sys/kern/sys_futex.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_futex.c,v 1.18 2022/04/21 12:05:13 riastradh Exp $ */
+/* $NetBSD: sys_futex.c,v 1.19 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 2018, 2019, 2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_futex.c,v 1.18 2022/04/21 12:05:13 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_futex.c,v 1.19 2023/02/24 11:02:27 riastradh Exp $");
/*
* Futexes
@@ -537,18 +537,14 @@ futex_rele(struct futex *f)
refcnt = atomic_load_relaxed(&f->fx_refcnt);
if (refcnt == 1)
goto trylast;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
} while (atomic_cas_ulong(&f->fx_refcnt, refcnt, refcnt - 1) != refcnt);
return;
trylast:
mutex_enter(&futex_tab.lock);
if (atomic_dec_ulong_nv(&f->fx_refcnt) == 0) {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
if (f->fx_on_tree) {
if (__predict_false(f->fx_shared))
rb_tree_remove_node(&futex_tab.oa, f);
Index: src/sys/kern/uipc_mbuf.c
diff -u src/sys/kern/uipc_mbuf.c:1.247 src/sys/kern/uipc_mbuf.c:1.248
--- src/sys/kern/uipc_mbuf.c:1.247 Fri Dec 16 08:42:55 2022
+++ src/sys/kern/uipc_mbuf.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: uipc_mbuf.c,v 1.247 2022/12/16 08:42:55 msaitoh Exp $ */
+/* $NetBSD: uipc_mbuf.c,v 1.248 2023/02/24 11:02:27 riastradh Exp $ */
/*
* Copyright (c) 1999, 2001, 2018 The NetBSD Foundation, Inc.
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.247 2022/12/16 08:42:55 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.248 2023/02/24 11:02:27 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_mbuftrace.h"
@@ -1923,9 +1923,7 @@ m_ext_free(struct mbuf *m)
if (__predict_true(m->m_ext.ext_refcnt == 1)) {
refcnt = m->m_ext.ext_refcnt = 0;
} else {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt);
}
@@ -1942,9 +1940,7 @@ m_ext_free(struct mbuf *m)
/*
* dropping the last reference
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
if (!embedded) {
m->m_ext.ext_refcnt++; /* XXX */
m_ext_free(m->m_ext_ref);
Index: src/sys/kern/vfs_mount.c
diff -u src/sys/kern/vfs_mount.c:1.101 src/sys/kern/vfs_mount.c:1.102
--- src/sys/kern/vfs_mount.c:1.101 Fri Dec 9 10:33:18 2022
+++ src/sys/kern/vfs_mount.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_mount.c,v 1.101 2022/12/09 10:33:18 hannken Exp $ */
+/* $NetBSD: vfs_mount.c,v 1.102 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 1997-2020 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.101 2022/12/09 10:33:18 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.102 2023/02/24 11:02:27 riastradh Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@@ -302,15 +302,11 @@ void
vfs_rele(struct mount *mp)
{
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
if (__predict_true((int)atomic_dec_uint_nv(&mp->mnt_refcnt) > 0)) {
return;
}
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
/*
* Nothing else has visibility of the mount: we can now
Index: src/sys/kern/vfs_vnode.c
diff -u src/sys/kern/vfs_vnode.c:1.148 src/sys/kern/vfs_vnode.c:1.149
--- src/sys/kern/vfs_vnode.c:1.148 Wed Feb 22 21:44:21 2023
+++ src/sys/kern/vfs_vnode.c Fri Feb 24 11:02:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_vnode.c,v 1.148 2023/02/22 21:44:21 riastradh Exp $ */
+/* $NetBSD: vfs_vnode.c,v 1.149 2023/02/24 11:02:27 riastradh Exp $ */
/*-
* Copyright (c) 1997-2011, 2019, 2020 The NetBSD Foundation, Inc.
@@ -148,7 +148,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.148 2023/02/22 21:44:21 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.149 2023/02/24 11:02:27 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_pax.h"
@@ -350,9 +350,7 @@ vstate_assert_change(vnode_t *vp, enum v
/* Open/close the gate for vcache_tryvget(). */
if (to == VS_LOADED) {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_or_uint(&vp->v_usecount, VUSECOUNT_GATE);
} else {
atomic_and_uint(&vp->v_usecount, ~VUSECOUNT_GATE);
@@ -396,9 +394,7 @@ vstate_change(vnode_t *vp, enum vnode_st
/* Open/close the gate for vcache_tryvget(). */
if (to == VS_LOADED) {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
atomic_or_uint(&vp->v_usecount, VUSECOUNT_GATE);
} else {
atomic_and_uint(&vp->v_usecount, ~VUSECOUNT_GATE);
@@ -732,9 +728,7 @@ vtryrele(vnode_t *vp)
{
u_int use, next;
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_release();
-#endif
for (use = atomic_load_relaxed(&vp->v_usecount);; use = next) {
if (__predict_false((use & VUSECOUNT_MASK) == 1)) {
return false;
@@ -832,9 +826,7 @@ retry:
break;
}
}
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
if (vrefcnt(vp) <= 0 || vp->v_writecount != 0) {
vnpanic(vp, "%s: bad ref count", __func__);
}
@@ -999,9 +991,7 @@ out:
break;
}
}
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
if (VSTATE_GET(vp) == VS_RECLAIMED && vp->v_holdcnt == 0) {
/*
@@ -1474,9 +1464,7 @@ vcache_tryvget(vnode_t *vp)
next = atomic_cas_uint(&vp->v_usecount,
use, (use + 1) | VUSECOUNT_VGET);
if (__predict_true(next == use)) {
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
membar_acquire();
-#endif
return 0;
}
}
