CVS commit: src/sys/kern
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:52:05 UTC 2022
Modified Files:
src/sys/kern: sys_select.c
Log Message:
select(9): Use membar_acquire/release and atomic_store_release.
No store-before-load ordering here -- this was obviously always
intended to be load-before-load/store all along.
To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.59 src/sys/kern/sys_select.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/sys_select.c
diff -u src/sys/kern/sys_select.c:1.58 src/sys/kern/sys_select.c:1.59
--- src/sys/kern/sys_select.c:1.58 Sat Feb 12 15:51:29 2022
+++ src/sys/kern/sys_select.c Sat Apr 9 23:52:05 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_select.c,v 1.58 2022/02/12 15:51:29 thorpej Exp $ */
+/* $NetBSD: sys_select.c,v 1.59 2022/04/09 23:52:05 riastradh Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2010, 2019, 2020 The NetBSD Foundation, Inc.
@@ -84,7 +84,7 @@
*/
#include
-__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.58 2022/02/12 15:51:29 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.59 2022/04/09 23:52:05 riastradh Exp $");
#include
#include
@@ -282,7 +282,7 @@ sel_do_scan(const char *opname, void *fd
l->l_selflag = SEL_SCANNING;
}
ncoll = sc->sc_ncoll;
- membar_exit();
+ membar_release();
if (opname == selop_select) {
error = selscan((char *)fds, nf, ni, retval);
@@ -653,7 +653,7 @@ selrecord(lwp_t *selector, struct selinf
* barrier to ensure that we access sel_lwp (above) before
* other fields - this guards against a call to selclear().
*/
- membar_enter();
+ membar_acquire();
sip->sel_lwp = selector;
SLIST_INSERT_HEAD(>l_selwait, sip, sel_chain);
/* Copy the argument, which is for selnotify(). */
@@ -872,9 +872,8 @@ selclear(void)
* globally visible.
*/
next = SLIST_NEXT(sip, sel_chain);
- membar_exit();
/* Release the record for another named waiter to use. */
- sip->sel_lwp = NULL;
+ atomic_store_release(>sel_lwp, NULL);
}
mutex_spin_exit(lock);
}
CVS commit: src/sys
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:52:23 UTC 2022 Modified Files: src/sys/kern: uipc_socket.c uipc_socket2.c uipc_usrreq.c src/sys/sys: socketvar.h Log Message: unix(4): Convert membar_exit to membar_release. Use atomic_load_consume or atomic_load_relaxed where necessary. Comment on why unlocked nonatomic access is valid where it is done. To generate a diff of this commit: cvs rdiff -u -r1.301 -r1.302 src/sys/kern/uipc_socket.c cvs rdiff -u -r1.140 -r1.141 src/sys/kern/uipc_socket2.c cvs rdiff -u -r1.201 -r1.202 src/sys/kern/uipc_usrreq.c cvs rdiff -u -r1.164 -r1.165 src/sys/sys/socketvar.h Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:32:53 UTC 2022 Modified Files: src/common/lib/libc/arch/aarch64/atomic: membar_ops.S src/common/lib/libc/arch/alpha/atomic: membar_ops.S src/common/lib/libc/arch/arm/atomic: membar_ops.S src/common/lib/libc/arch/hppa/atomic: membar_ops.S src/common/lib/libc/arch/i386/atomic: atomic.S src/common/lib/libc/arch/ia64/atomic: atomic.S src/common/lib/libc/arch/mips/atomic: membar_ops.S src/common/lib/libc/arch/or1k/atomic: membar_ops.S src/common/lib/libc/arch/powerpc/atomic: membar_ops.S src/common/lib/libc/arch/riscv/atomic: membar_ops.S src/common/lib/libc/arch/sparc/atomic: membar_ops.S src/common/lib/libc/arch/sparc64/atomic: membar_ops.S src/common/lib/libc/arch/x86_64/atomic: atomic.S src/common/lib/libc/atomic: membar_ops_nop.c src/distrib/sets/lists/comp: mi src/lib/libc/atomic: Makefile.inc membar_ops.3 src/share/man/man9: atomic_loadstore.9 src/sys/sys: atomic.h src/tests/lib/libc/membar: t_dekker.c t_spinlock.c Log Message: Introduce membar_acquire/release. Deprecate membar_enter/exit. The names membar_enter/exit were unclear, and the documentation of membar_enter has disagreed with the implementations on sparc, powerpc, and even x86(!) for the entire time it has been in NetBSD. The terms `acquire' and `release' are ubiquitous in the literature today, and have been adopted in the C and C++ standards to mean load-before-load/store and load/store-before-store, respectively, which are exactly the orderings required by acquiring and releasing a mutex, as well as other useful applications like decrementing a reference count and then freeing the underlying object if it went to zero. Originally I proposed changing one word in the documentation for membar_enter to make it load-before-load/store instead of store-before-load/store, i.e., to make it an acquire barrier. I proposed this on the grounds that (a) all implementations guarantee load-before-load/store, (b) some implementations fail to guarantee store-before-load/store, and (c) all uses in-tree assume load-before-load/store. I verified parts (a) and (b) (except, for (a), powerpc didn't even guarantee load-before-load/store -- isync isn't necessarily enough; need lwsync in general -- but it _almost_ did, and it certainly didn't guarantee store-before-load/store). Part (c) might not be correct, however: under the mistaken assumption that atomic-r/m/w then membar-w/rw is equivalent to atomic-r/m/w then membar-r/rw, I only audited the cases of membar_enter that _aren't_ immediately after an atomic-r/m/w. All of those cases assume load-before-load/store. But my assumption was wrong -- there are cases of atomic-r/m/w then membar-w/rw that would be broken by changing to atomic-r/m/w then membar-r/rw: https://mail-index.netbsd.org/tech-kern/2022/03/29/msg028044.html Furthermore, the name membar_enter has been adopted in other places like OpenBSD where it actually does follow the documentation and guarantee store-before-load/store, even if that order is not useful. So the name membar_enter currently lives in a bad place where it means either of two things -- r/rw or w/rw. With this change, we deprecate membar_enter/exit, introduce membar_acquire/release as better names for the useful pair (r/rw and rw/w), and make sure the implementation of membar_enter guarantees both what was documented _and_ what was implemented, making it an alias for membar_sync. While here, rework all of the membar_* definitions and aliases. The new logic follows a rule to make it easier to audit: membar_X is defined as an alias for membar_Y iff membar_X is guaranteed by membar_Y. The `no stronger than' relation is (the transitive closure of): - membar_consumer (r/r) is guaranteed by membar_acquire (r/rw) - membar_producer (w/w) is guaranteed by membar_release (rw/w) - membar_acquire (r/rw) is guaranteed by membar_sync (rw/rw) - membar_release (rw/w) is guaranteed by membar_sync (rw/rw) And, for the deprecated membars: - membar_enter (whether r/rw, w/rw, or rw/rw) is guaranteed by membar_sync (rw/rw) - membar_exit (rw/w) is guaranteed by membar_release (rw/w) (membar_exit is identical to membar_release, but the name is deprecated.) Finally, while here, annotate some of the instructions with their semantics. For powerpc, leave an essay with citations on the unfortunate but -- as far as I can tell -- necessary decision to use lwsync, not isync, for membar_acquire and membar_consumer. Also add membar(3) and atomic(3) man page links. To generate a diff of this commit: cvs rdiff -u -r1.3 -r1.4 src/common/lib/libc/arch/aarch64/atomic/membar_ops.S cvs rdiff -u -r1.8 -r1.9 src/common/lib/libc/arch/alpha/atomic/membar_ops.S cvs rdiff -u -r1.9 -r1.10 src/common/lib/libc/arch/arm/atomic/membar_ops.S cvs rdiff -u -r1.2 -r1.3
CVS commit: src
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:32:53 UTC 2022 Modified Files: src/common/lib/libc/arch/aarch64/atomic: membar_ops.S src/common/lib/libc/arch/alpha/atomic: membar_ops.S src/common/lib/libc/arch/arm/atomic: membar_ops.S src/common/lib/libc/arch/hppa/atomic: membar_ops.S src/common/lib/libc/arch/i386/atomic: atomic.S src/common/lib/libc/arch/ia64/atomic: atomic.S src/common/lib/libc/arch/mips/atomic: membar_ops.S src/common/lib/libc/arch/or1k/atomic: membar_ops.S src/common/lib/libc/arch/powerpc/atomic: membar_ops.S src/common/lib/libc/arch/riscv/atomic: membar_ops.S src/common/lib/libc/arch/sparc/atomic: membar_ops.S src/common/lib/libc/arch/sparc64/atomic: membar_ops.S src/common/lib/libc/arch/x86_64/atomic: atomic.S src/common/lib/libc/atomic: membar_ops_nop.c src/distrib/sets/lists/comp: mi src/lib/libc/atomic: Makefile.inc membar_ops.3 src/share/man/man9: atomic_loadstore.9 src/sys/sys: atomic.h src/tests/lib/libc/membar: t_dekker.c t_spinlock.c Log Message: Introduce membar_acquire/release. Deprecate membar_enter/exit. The names membar_enter/exit were unclear, and the documentation of membar_enter has disagreed with the implementations on sparc, powerpc, and even x86(!) for the entire time it has been in NetBSD. The terms `acquire' and `release' are ubiquitous in the literature today, and have been adopted in the C and C++ standards to mean load-before-load/store and load/store-before-store, respectively, which are exactly the orderings required by acquiring and releasing a mutex, as well as other useful applications like decrementing a reference count and then freeing the underlying object if it went to zero. Originally I proposed changing one word in the documentation for membar_enter to make it load-before-load/store instead of store-before-load/store, i.e., to make it an acquire barrier. I proposed this on the grounds that (a) all implementations guarantee load-before-load/store, (b) some implementations fail to guarantee store-before-load/store, and (c) all uses in-tree assume load-before-load/store. I verified parts (a) and (b) (except, for (a), powerpc didn't even guarantee load-before-load/store -- isync isn't necessarily enough; need lwsync in general -- but it _almost_ did, and it certainly didn't guarantee store-before-load/store). Part (c) might not be correct, however: under the mistaken assumption that atomic-r/m/w then membar-w/rw is equivalent to atomic-r/m/w then membar-r/rw, I only audited the cases of membar_enter that _aren't_ immediately after an atomic-r/m/w. All of those cases assume load-before-load/store. But my assumption was wrong -- there are cases of atomic-r/m/w then membar-w/rw that would be broken by changing to atomic-r/m/w then membar-r/rw: https://mail-index.netbsd.org/tech-kern/2022/03/29/msg028044.html Furthermore, the name membar_enter has been adopted in other places like OpenBSD where it actually does follow the documentation and guarantee store-before-load/store, even if that order is not useful. So the name membar_enter currently lives in a bad place where it means either of two things -- r/rw or w/rw. With this change, we deprecate membar_enter/exit, introduce membar_acquire/release as better names for the useful pair (r/rw and rw/w), and make sure the implementation of membar_enter guarantees both what was documented _and_ what was implemented, making it an alias for membar_sync. While here, rework all of the membar_* definitions and aliases. The new logic follows a rule to make it easier to audit: membar_X is defined as an alias for membar_Y iff membar_X is guaranteed by membar_Y. The `no stronger than' relation is (the transitive closure of): - membar_consumer (r/r) is guaranteed by membar_acquire (r/rw) - membar_producer (w/w) is guaranteed by membar_release (rw/w) - membar_acquire (r/rw) is guaranteed by membar_sync (rw/rw) - membar_release (rw/w) is guaranteed by membar_sync (rw/rw) And, for the deprecated membars: - membar_enter (whether r/rw, w/rw, or rw/rw) is guaranteed by membar_sync (rw/rw) - membar_exit (rw/w) is guaranteed by membar_release (rw/w) (membar_exit is identical to membar_release, but the name is deprecated.) Finally, while here, annotate some of the instructions with their semantics. For powerpc, leave an essay with citations on the unfortunate but -- as far as I can tell -- necessary decision to use lwsync, not isync, for membar_acquire and membar_consumer. Also add membar(3) and atomic(3) man page links. To generate a diff of this commit: cvs rdiff -u -r1.3 -r1.4 src/common/lib/libc/arch/aarch64/atomic/membar_ops.S cvs rdiff -u -r1.8 -r1.9 src/common/lib/libc/arch/alpha/atomic/membar_ops.S cvs rdiff -u -r1.9 -r1.10 src/common/lib/libc/arch/arm/atomic/membar_ops.S cvs rdiff -u -r1.2 -r1.3
CVS commit: src/sys
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:38:33 UTC 2022 Modified Files: src/sys/arch/aarch64/aarch64: pmap.c src/sys/arch/alpha/alpha: pmap.c src/sys/arch/arm/arm32: pmap.c src/sys/arch/hppa/hppa: pmap.c src/sys/arch/ia64/ia64: pmap.c src/sys/arch/powerpc/oea: pmap.c src/sys/arch/sparc/sparc: pmap.c src/sys/arch/sparc64/sparc64: pmap.c src/sys/dev/hyperv: vmbus.c src/sys/dev/marvell: mvxpsec.c src/sys/dev/scsipi: atapiconf.c scsiconf.c scsipi_base.c src/sys/external/bsd/drm2/linux: linux_stop_machine.c src/sys/kern: kern_auth.c kern_exec.c kern_mutex_obj.c kern_resource.c kern_rwlock_obj.c kern_sig.c subr_kcpuset.c sys_futex.c uipc_mbuf.c vfs_cwd.c vfs_mount.c vfs_vnode.c vfs_wapbl.c src/sys/net: if.c src/sys/net/npf: npf_nat.c npf_rproc.c npf_tableset.c src/sys/uvm: uvm_aobj.c uvm_map.c src/sys/uvm/pmap: pmap.c Log Message: sys: Use membar_release/acquire around reference drop. This just goes through my recent reference count membar audit and changes membar_exit to membar_release and membar_enter to membar_acquire -- this should make everything cheaper on most CPUs without hurting correctness, because membar_acquire is generally cheaper than membar_enter. To generate a diff of this commit: cvs rdiff -u -r1.132 -r1.133 src/sys/arch/aarch64/aarch64/pmap.c cvs rdiff -u -r1.306 -r1.307 src/sys/arch/alpha/alpha/pmap.c cvs rdiff -u -r1.435 -r1.436 src/sys/arch/arm/arm32/pmap.c cvs rdiff -u -r1.115 -r1.116 src/sys/arch/hppa/hppa/pmap.c cvs rdiff -u -r1.41 -r1.42 src/sys/arch/ia64/ia64/pmap.c cvs rdiff -u -r1.112 -r1.113 src/sys/arch/powerpc/oea/pmap.c cvs rdiff -u -r1.376 -r1.377 src/sys/arch/sparc/sparc/pmap.c cvs rdiff -u -r1.315 -r1.316 src/sys/arch/sparc64/sparc64/pmap.c cvs rdiff -u -r1.16 -r1.17 src/sys/dev/hyperv/vmbus.c cvs rdiff -u -r1.12 -r1.13 src/sys/dev/marvell/mvxpsec.c cvs rdiff -u -r1.94 -r1.95 src/sys/dev/scsipi/atapiconf.c cvs rdiff -u -r1.300 -r1.301 src/sys/dev/scsipi/scsiconf.c cvs rdiff -u -r1.188 -r1.189 src/sys/dev/scsipi/scsipi_base.c cvs rdiff -u -r1.3 -r1.4 src/sys/external/bsd/drm2/linux/linux_stop_machine.c cvs rdiff -u -r1.80 -r1.81 src/sys/kern/kern_auth.c cvs rdiff -u -r1.516 -r1.517 src/sys/kern/kern_exec.c cvs rdiff -u -r1.8 -r1.9 src/sys/kern/kern_mutex_obj.c cvs rdiff -u -r1.188 -r1.189 src/sys/kern/kern_resource.c cvs rdiff -u -r1.6 -r1.7 src/sys/kern/kern_rwlock_obj.c cvs rdiff -u -r1.403 -r1.404 src/sys/kern/kern_sig.c cvs rdiff -u -r1.13 -r1.14 src/sys/kern/subr_kcpuset.c cvs rdiff -u -r1.16 -r1.17 src/sys/kern/sys_futex.c cvs rdiff -u -r1.245 -r1.246 src/sys/kern/uipc_mbuf.c cvs rdiff -u -r1.7 -r1.8 src/sys/kern/vfs_cwd.c cvs rdiff -u -r1.92 -r1.93 src/sys/kern/vfs_mount.c cvs rdiff -u -r1.141 -r1.142 src/sys/kern/vfs_vnode.c cvs rdiff -u -r1.111 -r1.112 src/sys/kern/vfs_wapbl.c cvs rdiff -u -r1.502 -r1.503 src/sys/net/if.c cvs rdiff -u -r1.51 -r1.52 src/sys/net/npf/npf_nat.c cvs rdiff -u -r1.21 -r1.22 src/sys/net/npf/npf_rproc.c cvs rdiff -u -r1.37 -r1.38 src/sys/net/npf/npf_tableset.c cvs rdiff -u -r1.154 -r1.155 src/sys/uvm/uvm_aobj.c cvs rdiff -u -r1.392 -r1.393 src/sys/uvm/uvm_map.c cvs rdiff -u -r1.63 -r1.64 src/sys/uvm/pmap/pmap.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:38:33 UTC 2022
Modified Files:
src/sys/arch/aarch64/aarch64: pmap.c
src/sys/arch/alpha/alpha: pmap.c
src/sys/arch/arm/arm32: pmap.c
src/sys/arch/hppa/hppa: pmap.c
src/sys/arch/ia64/ia64: pmap.c
src/sys/arch/powerpc/oea: pmap.c
src/sys/arch/sparc/sparc: pmap.c
src/sys/arch/sparc64/sparc64: pmap.c
src/sys/dev/hyperv: vmbus.c
src/sys/dev/marvell: mvxpsec.c
src/sys/dev/scsipi: atapiconf.c scsiconf.c scsipi_base.c
src/sys/external/bsd/drm2/linux: linux_stop_machine.c
src/sys/kern: kern_auth.c kern_exec.c kern_mutex_obj.c kern_resource.c
kern_rwlock_obj.c kern_sig.c subr_kcpuset.c sys_futex.c uipc_mbuf.c
vfs_cwd.c vfs_mount.c vfs_vnode.c vfs_wapbl.c
src/sys/net: if.c
src/sys/net/npf: npf_nat.c npf_rproc.c npf_tableset.c
src/sys/uvm: uvm_aobj.c uvm_map.c
src/sys/uvm/pmap: pmap.c
Log Message:
sys: Use membar_release/acquire around reference drop.
This just goes through my recent reference count membar audit and
changes membar_exit to membar_release and membar_enter to
membar_acquire -- this should make everything cheaper on most CPUs
without hurting correctness, because membar_acquire is generally
cheaper than membar_enter.
To generate a diff of this commit:
cvs rdiff -u -r1.132 -r1.133 src/sys/arch/aarch64/aarch64/pmap.c
cvs rdiff -u -r1.306 -r1.307 src/sys/arch/alpha/alpha/pmap.c
cvs rdiff -u -r1.435 -r1.436 src/sys/arch/arm/arm32/pmap.c
cvs rdiff -u -r1.115 -r1.116 src/sys/arch/hppa/hppa/pmap.c
cvs rdiff -u -r1.41 -r1.42 src/sys/arch/ia64/ia64/pmap.c
cvs rdiff -u -r1.112 -r1.113 src/sys/arch/powerpc/oea/pmap.c
cvs rdiff -u -r1.376 -r1.377 src/sys/arch/sparc/sparc/pmap.c
cvs rdiff -u -r1.315 -r1.316 src/sys/arch/sparc64/sparc64/pmap.c
cvs rdiff -u -r1.16 -r1.17 src/sys/dev/hyperv/vmbus.c
cvs rdiff -u -r1.12 -r1.13 src/sys/dev/marvell/mvxpsec.c
cvs rdiff -u -r1.94 -r1.95 src/sys/dev/scsipi/atapiconf.c
cvs rdiff -u -r1.300 -r1.301 src/sys/dev/scsipi/scsiconf.c
cvs rdiff -u -r1.188 -r1.189 src/sys/dev/scsipi/scsipi_base.c
cvs rdiff -u -r1.3 -r1.4 src/sys/external/bsd/drm2/linux/linux_stop_machine.c
cvs rdiff -u -r1.80 -r1.81 src/sys/kern/kern_auth.c
cvs rdiff -u -r1.516 -r1.517 src/sys/kern/kern_exec.c
cvs rdiff -u -r1.8 -r1.9 src/sys/kern/kern_mutex_obj.c
cvs rdiff -u -r1.188 -r1.189 src/sys/kern/kern_resource.c
cvs rdiff -u -r1.6 -r1.7 src/sys/kern/kern_rwlock_obj.c
cvs rdiff -u -r1.403 -r1.404 src/sys/kern/kern_sig.c
cvs rdiff -u -r1.13 -r1.14 src/sys/kern/subr_kcpuset.c
cvs rdiff -u -r1.16 -r1.17 src/sys/kern/sys_futex.c
cvs rdiff -u -r1.245 -r1.246 src/sys/kern/uipc_mbuf.c
cvs rdiff -u -r1.7 -r1.8 src/sys/kern/vfs_cwd.c
cvs rdiff -u -r1.92 -r1.93 src/sys/kern/vfs_mount.c
cvs rdiff -u -r1.141 -r1.142 src/sys/kern/vfs_vnode.c
cvs rdiff -u -r1.111 -r1.112 src/sys/kern/vfs_wapbl.c
cvs rdiff -u -r1.502 -r1.503 src/sys/net/if.c
cvs rdiff -u -r1.51 -r1.52 src/sys/net/npf/npf_nat.c
cvs rdiff -u -r1.21 -r1.22 src/sys/net/npf/npf_rproc.c
cvs rdiff -u -r1.37 -r1.38 src/sys/net/npf/npf_tableset.c
cvs rdiff -u -r1.154 -r1.155 src/sys/uvm/uvm_aobj.c
cvs rdiff -u -r1.392 -r1.393 src/sys/uvm/uvm_map.c
cvs rdiff -u -r1.63 -r1.64 src/sys/uvm/pmap/pmap.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/arch/aarch64/aarch64/pmap.c
diff -u src/sys/arch/aarch64/aarch64/pmap.c:1.132 src/sys/arch/aarch64/aarch64/pmap.c:1.133
--- src/sys/arch/aarch64/aarch64/pmap.c:1.132 Sat Apr 2 11:16:06 2022
+++ src/sys/arch/aarch64/aarch64/pmap.c Sat Apr 9 23:38:31 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.132 2022/04/02 11:16:06 skrll Exp $ */
+/* $NetBSD: pmap.c,v 1.133 2022/04/09 23:38:31 riastradh Exp $ */
/*
* Copyright (c) 2017 Ryo Shimizu
@@ -27,7 +27,7 @@
*/
#include
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.132 2022/04/02 11:16:06 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.133 2022/04/09 23:38:31 riastradh Exp $");
#include "opt_arm_debug.h"
#include "opt_cpuoptions.h"
@@ -1651,11 +1651,11 @@ pmap_destroy(struct pmap *pm)
if (pm == pmap_kernel())
panic("cannot destroy kernel pmap");
- membar_exit();
+ membar_release();
refcnt = atomic_dec_uint_nv(>pm_refcnt);
if (refcnt > 0)
return;
- membar_enter();
+ membar_acquire();
KASSERT(LIST_EMPTY(>pm_pvlist));
pmap_tlb_asid_release_all(pm);
Index: src/sys/arch/alpha/alpha/pmap.c
diff -u src/sys/arch/alpha/alpha/pmap.c:1.306 src/sys/arch/alpha/alpha/pmap.c:1.307
--- src/sys/arch/alpha/alpha/pmap.c:1.306 Sat Apr 9 23:36:22 2022
+++ src/sys/arch/alpha/alpha/pmap.c Sat Apr 9 23:38:31 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.306 2022/04/09 23:36:22 riastradh Exp $ */
+/* $NetBSD: pmap.c,v 1.307 2022/04/09 23:38:31 riastradh Exp $ */
/*-
* Copyright (c) 1998, 1999, 2000, 2001, 2007, 2008, 2020
@@ -135,7
CVS commit: src/common/lib/libc/atomic
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:38:57 UTC 2022 Modified Files: src/common/lib/libc/atomic: atomic_load.c atomic_store.c Log Message: libc/atomic: Fix membars in __atomic_load/store_* stubs. - membar_enter/exit ordering was backwards. - membar_enter doesn't make any sense for load anyway. - Switch to membar_release for store and membar_acquire for load. The only sensible orderings for a simple load or store are acquire or release, respectively, or sequential consistency. This never provided correct sequential consistency before -- we should really make it conditional on memmodel but I don't know offhand what the values of memmodel might be and this is at least better than before. To generate a diff of this commit: cvs rdiff -u -r1.3 -r1.4 src/common/lib/libc/atomic/atomic_load.c \ src/common/lib/libc/atomic/atomic_store.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/common/lib/libc/atomic
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:38:57 UTC 2022
Modified Files:
src/common/lib/libc/atomic: atomic_load.c atomic_store.c
Log Message:
libc/atomic: Fix membars in __atomic_load/store_* stubs.
- membar_enter/exit ordering was backwards.
- membar_enter doesn't make any sense for load anyway.
- Switch to membar_release for store and membar_acquire for load.
The only sensible orderings for a simple load or store are acquire or
release, respectively, or sequential consistency. This never
provided correct sequential consistency before -- we should really
make it conditional on memmodel but I don't know offhand what the
values of memmodel might be and this is at least better than before.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/common/lib/libc/atomic/atomic_load.c \
src/common/lib/libc/atomic/atomic_store.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/common/lib/libc/atomic/atomic_load.c
diff -u src/common/lib/libc/atomic/atomic_load.c:1.3 src/common/lib/libc/atomic/atomic_load.c:1.4
--- src/common/lib/libc/atomic/atomic_load.c:1.3 Mon Sep 7 00:52:19 2020
+++ src/common/lib/libc/atomic/atomic_load.c Sat Apr 9 23:38:57 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: atomic_load.c,v 1.3 2020/09/07 00:52:19 mrg Exp $ */
+/* $NetBSD: atomic_load.c,v 1.4 2022/04/09 23:38:57 riastradh Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -27,7 +27,7 @@
*/
#include
-__RCSID("$NetBSD: atomic_load.c,v 1.3 2020/09/07 00:52:19 mrg Exp $");
+__RCSID("$NetBSD: atomic_load.c,v 1.4 2022/04/09 23:38:57 riastradh Exp $");
#include "atomic_op_namespace.h"
@@ -40,9 +40,8 @@ uint ## b ## _t \
__atomic_load_ ## n(const volatile void *ptr, int memmodel) \
{ \
uint## b ##_t val; \
- membar_enter(); \
val = *(const volatile uint ## b ## _t *)ptr; \
- membar_exit(); \
+ membar_acquire(); \
return val; \
}
Index: src/common/lib/libc/atomic/atomic_store.c
diff -u src/common/lib/libc/atomic/atomic_store.c:1.3 src/common/lib/libc/atomic/atomic_store.c:1.4
--- src/common/lib/libc/atomic/atomic_store.c:1.3 Mon Sep 7 00:52:19 2020
+++ src/common/lib/libc/atomic/atomic_store.c Sat Apr 9 23:38:57 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: atomic_store.c,v 1.3 2020/09/07 00:52:19 mrg Exp $ */
+/* $NetBSD: atomic_store.c,v 1.4 2022/04/09 23:38:57 riastradh Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -27,7 +27,7 @@
*/
#include
-__RCSID("$NetBSD: atomic_store.c,v 1.3 2020/09/07 00:52:19 mrg Exp $");
+__RCSID("$NetBSD: atomic_store.c,v 1.4 2022/04/09 23:38:57 riastradh Exp $");
#include "atomic_op_namespace.h"
@@ -40,9 +40,8 @@ void \
__atomic_store_ ## n(volatile void *ptr, uint ## b ## _t val, \
int memmodel) \
{ \
- membar_enter(); \
+ membar_release(); \
*(volatile uint ## b ## _t *)ptr = val; \
- membar_exit(); \
}
atomic_store_n(1, 8)
CVS commit: src/libexec/ld.elf_so
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:39:07 UTC 2022
Modified Files:
src/libexec/ld.elf_so: rtld.c
Log Message:
rtld: Convert membar_exit/enter to membar_release/acquire.
These are basic CAS-based locking primitives needing release and
acquire semantics, nothing fancy here -- except the membar_sync parts
which are questionable but not relevant to the present audit.
To generate a diff of this commit:
cvs rdiff -u -r1.210 -r1.211 src/libexec/ld.elf_so/rtld.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/libexec/ld.elf_so/rtld.c
diff -u src/libexec/ld.elf_so/rtld.c:1.210 src/libexec/ld.elf_so/rtld.c:1.211
--- src/libexec/ld.elf_so/rtld.c:1.210 Sat Dec 4 14:39:08 2021
+++ src/libexec/ld.elf_so/rtld.c Sat Apr 9 23:39:07 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: rtld.c,v 1.210 2021/12/04 14:39:08 skrll Exp $ */
+/* $NetBSD: rtld.c,v 1.211 2022/04/09 23:39:07 riastradh Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
#include
#ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.210 2021/12/04 14:39:08 skrll Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.211 2022/04/09 23:39:07 riastradh Exp $");
#endif /* not lint */
#include
@@ -1682,7 +1682,7 @@ _rtld_shared_enter(void)
/* Yes, so increment use counter */
if (atomic_cas_uint(&_rtld_mutex, cur, cur + 1) != cur)
continue;
- membar_enter();
+ membar_acquire();
return;
}
/*
@@ -1728,7 +1728,7 @@ _rtld_shared_exit(void)
* Wakeup LWPs waiting for an exclusive lock if this is the last
* LWP on the shared lock.
*/
- membar_exit();
+ membar_release();
if (atomic_dec_uint_nv(&_rtld_mutex))
return;
membar_sync();
@@ -1750,7 +1750,7 @@ _rtld_exclusive_enter(sigset_t *mask)
for (;;) {
if (atomic_cas_uint(&_rtld_mutex, 0, locked_value) == 0) {
- membar_enter();
+ membar_acquire();
break;
}
waiter = atomic_swap_uint(&_rtld_waiter_exclusive, self);
@@ -1774,7 +1774,7 @@ _rtld_exclusive_exit(sigset_t *mask)
{
lwpid_t waiter;
- membar_exit();
+ membar_release();
_rtld_mutex = 0;
membar_sync();
if ((waiter = _rtld_waiter_exclusive) != 0)
CVS commit: src/sys/arch/alpha/alpha
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:39:18 UTC 2022 Modified Files: src/sys/arch/alpha/alpha: cpu.c Log Message: alpha: Convert cpu_iccb_send from membar_exit to membar_release. XXX Maybe this should really use alpha_mb, since it's not writing to normal MI-type memory so technically the membr_* semantics doesn't apply? To generate a diff of this commit: cvs rdiff -u -r1.105 -r1.106 src/sys/arch/alpha/alpha/cpu.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/arch/alpha/alpha
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:39:18 UTC 2022 Modified Files: src/sys/arch/alpha/alpha: cpu.c Log Message: alpha: Convert cpu_iccb_send from membar_exit to membar_release. XXX Maybe this should really use alpha_mb, since it's not writing to normal MI-type memory so technically the membr_* semantics doesn't apply? To generate a diff of this commit: cvs rdiff -u -r1.105 -r1.106 src/sys/arch/alpha/alpha/cpu.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/arch/alpha/alpha/cpu.c diff -u src/sys/arch/alpha/alpha/cpu.c:1.105 src/sys/arch/alpha/alpha/cpu.c:1.106 --- src/sys/arch/alpha/alpha/cpu.c:1.105 Sun Feb 27 14:17:10 2022 +++ src/sys/arch/alpha/alpha/cpu.c Sat Apr 9 23:39:18 2022 @@ -1,4 +1,4 @@ -/* $NetBSD: cpu.c,v 1.105 2022/02/27 14:17:10 riastradh Exp $ */ +/* $NetBSD: cpu.c,v 1.106 2022/04/09 23:39:18 riastradh Exp $ */ /*- * Copyright (c) 1998, 1999, 2000, 2001, 2020 The NetBSD Foundation, Inc. @@ -59,7 +59,7 @@ #include /* RCS ID & Copyright macro defns */ -__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.105 2022/02/27 14:17:10 riastradh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.106 2022/04/09 23:39:18 riastradh Exp $"); #include "opt_ddb.h" #include "opt_multiprocessor.h" @@ -887,7 +887,7 @@ cpu_iccb_send(long cpu_id, const char *m */ strcpy(pcsp->pcs_iccb.iccb_rxbuf, msg); pcsp->pcs_iccb.iccb_rxlen = strlen(msg); - membar_exit(); + membar_release(); atomic_or_ulong(>rpb_rxrdy, cpumask); /* Wait for the message to be received. */
CVS commit: src/libexec/ld.elf_so
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:39:07 UTC 2022 Modified Files: src/libexec/ld.elf_so: rtld.c Log Message: rtld: Convert membar_exit/enter to membar_release/acquire. These are basic CAS-based locking primitives needing release and acquire semantics, nothing fancy here -- except the membar_sync parts which are questionable but not relevant to the present audit. To generate a diff of this commit: cvs rdiff -u -r1.210 -r1.211 src/libexec/ld.elf_so/rtld.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/dev/audio
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:35:58 UTC 2022 Modified Files: src/sys/dev/audio: audio.c Log Message: audio(4): Use membar_acquire, not membar_enter. Cheaper and adequate to make an atomic_swap into a load-acquire. To generate a diff of this commit: cvs rdiff -u -r1.122 -r1.123 src/sys/dev/audio/audio.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/dev/audio/audio.c diff -u src/sys/dev/audio/audio.c:1.122 src/sys/dev/audio/audio.c:1.123 --- src/sys/dev/audio/audio.c:1.122 Thu Mar 31 19:30:15 2022 +++ src/sys/dev/audio/audio.c Sat Apr 9 23:35:58 2022 @@ -1,4 +1,4 @@ -/* $NetBSD: audio.c,v 1.122 2022/03/31 19:30:15 pgoyette Exp $ */ +/* $NetBSD: audio.c,v 1.123 2022/04/09 23:35:58 riastradh Exp $ */ /*- * Copyright (c) 2008 The NetBSD Foundation, Inc. @@ -181,7 +181,7 @@ */ #include -__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.122 2022/03/31 19:30:15 pgoyette Exp $"); +__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.123 2022/04/09 23:35:58 riastradh Exp $"); #ifdef _KERNEL_OPT #include "audio.h" @@ -316,7 +316,7 @@ audio_mlog_flush(void) /* Nothing to do if already in use ? */ if (atomic_swap_32(_inuse, 1) == 1) return; - membar_enter(); + membar_acquire(); int rpage = mlog_wpage; mlog_wpage ^= 1; @@ -353,7 +353,7 @@ audio_mlog_printf(const char *fmt, ...) mlog_drop++; return; } - membar_enter(); + membar_acquire(); va_start(ap, fmt); len = vsnprintf( @@ -1684,7 +1684,7 @@ audio_track_lock_tryenter(audio_track_t if (atomic_swap_uint(>lock, 1) != 0) return false; - membar_enter(); + membar_acquire(); return true; }
CVS commit: src/sys/dev/audio
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:35:58 UTC 2022 Modified Files: src/sys/dev/audio: audio.c Log Message: audio(4): Use membar_acquire, not membar_enter. Cheaper and adequate to make an atomic_swap into a load-acquire. To generate a diff of this commit: cvs rdiff -u -r1.122 -r1.123 src/sys/dev/audio/audio.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/arch/alpha/alpha
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:36:22 UTC 2022 Modified Files: src/sys/arch/alpha/alpha: pmap.c Log Message: alpha: Omit needless membar in pmap_reference. If the pmap is published enough for us to obtain a reference to it then there's no membar needed. If it's not then something else is wrong and we can't use pmap_reference here anyway. Membars are needed only on the destruction side to make sure all use, by any thread, happens-before all freeing in the last user thread. To generate a diff of this commit: cvs rdiff -u -r1.305 -r1.306 src/sys/arch/alpha/alpha/pmap.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/arch/alpha/alpha
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:36:22 UTC 2022 Modified Files: src/sys/arch/alpha/alpha: pmap.c Log Message: alpha: Omit needless membar in pmap_reference. If the pmap is published enough for us to obtain a reference to it then there's no membar needed. If it's not then something else is wrong and we can't use pmap_reference here anyway. Membars are needed only on the destruction side to make sure all use, by any thread, happens-before all freeing in the last user thread. To generate a diff of this commit: cvs rdiff -u -r1.305 -r1.306 src/sys/arch/alpha/alpha/pmap.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/arch/alpha/alpha/pmap.c diff -u src/sys/arch/alpha/alpha/pmap.c:1.305 src/sys/arch/alpha/alpha/pmap.c:1.306 --- src/sys/arch/alpha/alpha/pmap.c:1.305 Sat Mar 12 15:32:31 2022 +++ src/sys/arch/alpha/alpha/pmap.c Sat Apr 9 23:36:22 2022 @@ -1,4 +1,4 @@ -/* $NetBSD: pmap.c,v 1.305 2022/03/12 15:32:31 riastradh Exp $ */ +/* $NetBSD: pmap.c,v 1.306 2022/04/09 23:36:22 riastradh Exp $ */ /*- * Copyright (c) 1998, 1999, 2000, 2001, 2007, 2008, 2020 @@ -135,7 +135,7 @@ #include /* RCS ID & Copyright macro defns */ -__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.305 2022/03/12 15:32:31 riastradh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.306 2022/04/09 23:36:22 riastradh Exp $"); #include #include @@ -1706,7 +1706,6 @@ pmap_reference(pmap_t pmap) newcount = atomic_inc_uint_nv(>pm_count); KASSERT(newcount != 0); - PMAP_MP(membar_enter()); } /*
CVS commit: src/sys/external/bsd/drm2/linux
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:44:45 UTC 2022 Modified Files: src/sys/external/bsd/drm2/linux: linux_dma_buf.c linux_dma_fence.c linux_dma_fence_chain.c Log Message: drm: Convert membar_enter/exit stragglers to membar_acquire/release. To generate a diff of this commit: cvs rdiff -u -r1.14 -r1.15 src/sys/external/bsd/drm2/linux/linux_dma_buf.c cvs rdiff -u -r1.39 -r1.40 src/sys/external/bsd/drm2/linux/linux_dma_fence.c cvs rdiff -u -r1.3 -r1.4 \ src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/external/bsd/drm2/linux
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:44:45 UTC 2022
Modified Files:
src/sys/external/bsd/drm2/linux: linux_dma_buf.c linux_dma_fence.c
linux_dma_fence_chain.c
Log Message:
drm: Convert membar_enter/exit stragglers to membar_acquire/release.
To generate a diff of this commit:
cvs rdiff -u -r1.14 -r1.15 src/sys/external/bsd/drm2/linux/linux_dma_buf.c
cvs rdiff -u -r1.39 -r1.40 src/sys/external/bsd/drm2/linux/linux_dma_fence.c
cvs rdiff -u -r1.3 -r1.4 \
src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.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/external/bsd/drm2/linux/linux_dma_buf.c
diff -u src/sys/external/bsd/drm2/linux/linux_dma_buf.c:1.14 src/sys/external/bsd/drm2/linux/linux_dma_buf.c:1.15
--- src/sys/external/bsd/drm2/linux/linux_dma_buf.c:1.14 Thu Feb 17 01:38:38 2022
+++ src/sys/external/bsd/drm2/linux/linux_dma_buf.c Sat Apr 9 23:44:44 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_buf.c,v 1.14 2022/02/17 01:38:38 riastradh Exp $ */
+/* $NetBSD: linux_dma_buf.c,v 1.15 2022/04/09 23:44:44 riastradh Exp $ */
/*-
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include
-__KERNEL_RCSID(0, "$NetBSD: linux_dma_buf.c,v 1.14 2022/02/17 01:38:38 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_buf.c,v 1.15 2022/04/09 23:44:44 riastradh Exp $");
#include
#include
@@ -160,10 +160,10 @@ void
dma_buf_put(struct dma_buf *dmabuf)
{
- membar_exit();
+ membar_release();
if (atomic_dec_uint_nv(>db_refcnt) != 0)
return;
- membar_enter();
+ membar_acquire();
dma_resv_poll_fini(>db_resv_poll);
mutex_destroy(>db_lock);
Index: src/sys/external/bsd/drm2/linux/linux_dma_fence.c
diff -u src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.39 src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.40
--- src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.39 Sun Dec 19 12:39:40 2021
+++ src/sys/external/bsd/drm2/linux/linux_dma_fence.c Sat Apr 9 23:44:44 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_fence.c,v 1.39 2021/12/19 12:39:40 riastradh Exp $ */
+/* $NetBSD: linux_dma_fence.c,v 1.40 2022/04/09 23:44:44 riastradh Exp $ */
/*-
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include
-__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence.c,v 1.39 2021/12/19 12:39:40 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence.c,v 1.40 2022/04/09 23:44:44 riastradh Exp $");
#include
#include
@@ -245,9 +245,9 @@ dma_fence_context_alloc(unsigned n)
} S;
uint64_t c;
- while (__predict_false(atomic_cas_uint(, 0, 1) != 0))
+ while (__predict_false(atomic_swap_uint(, 1)))
SPINLOCK_BACKOFF_HOOK;
- membar_enter();
+ membar_acquire();
c = S.context;
S.context += n;
atomic_store_release(, 0);
Index: src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c
diff -u src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c:1.3 src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c:1.4
--- src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c:1.3 Sun Dec 19 12:39:32 2021
+++ src/sys/external/bsd/drm2/linux/linux_dma_fence_chain.c Sat Apr 9 23:44:44 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_fence_chain.c,v 1.3 2021/12/19 12:39:32 riastradh Exp $ */
+/* $NetBSD: linux_dma_fence_chain.c,v 1.4 2022/04/09 23:44:44 riastradh Exp $ */
/*-
* Copyright (c) 2021 The NetBSD Foundation, Inc.
@@ -27,7 +27,7 @@
*/
#include
-__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence_chain.c,v 1.3 2021/12/19 12:39:32 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence_chain.c,v 1.4 2022/04/09 23:44:44 riastradh Exp $");
#include
@@ -262,7 +262,7 @@ dma_fence_chain_walk(struct dma_fence *f
break;
splice = NULL;
}
- membar_exit(); /* pairs with dma_fence_get_rcu_safe */
+ membar_release(); /* pairs with dma_fence_get_rcu_safe */
if (atomic_cas_ptr(>dfc_prev, prev, splice) == prev)
dma_fence_put(prev); /* transferred to splice */
else
CVS commit: src/sys/external/bsd/drm2/include/linux
Module Name:src Committed By: riastradh Date: Sat Apr 9 23:44:25 UTC 2022 Modified Files: src/sys/external/bsd/drm2/include/linux: ratelimit.h Log Message: linux/ratelimit: Convert to membar_acquire and atomic_store_release. Simplify while here: atomic_swap is enough, no need for atomic_cas. (Maybe drm'll run faster on sparcv8 this way...!) To generate a diff of this commit: cvs rdiff -u -r1.5 -r1.6 src/sys/external/bsd/drm2/include/linux/ratelimit.h Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
CVS commit: src/sys/external/bsd/drm2/include/linux
Module Name:src
Committed By: riastradh
Date: Sat Apr 9 23:44:25 UTC 2022
Modified Files:
src/sys/external/bsd/drm2/include/linux: ratelimit.h
Log Message:
linux/ratelimit: Convert to membar_acquire and atomic_store_release.
Simplify while here: atomic_swap is enough, no need for atomic_cas.
(Maybe drm'll run faster on sparcv8 this way...!)
To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/sys/external/bsd/drm2/include/linux/ratelimit.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/include/linux/ratelimit.h
diff -u src/sys/external/bsd/drm2/include/linux/ratelimit.h:1.5 src/sys/external/bsd/drm2/include/linux/ratelimit.h:1.6
--- src/sys/external/bsd/drm2/include/linux/ratelimit.h:1.5 Sun Dec 19 11:36:57 2021
+++ src/sys/external/bsd/drm2/include/linux/ratelimit.h Sat Apr 9 23:44:25 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: ratelimit.h,v 1.5 2021/12/19 11:36:57 riastradh Exp $ */
+/* $NetBSD: ratelimit.h,v 1.6 2022/04/09 23:44:25 riastradh Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -86,14 +86,13 @@ __ratelimit(struct ratelimit_state *r)
{
int ok;
- if (atomic_cas_uint(>rl_lock, 0, 1)) {
+ if (atomic_swap_uint(>rl_lock, 1)) {
ok = false;
goto out;
}
- membar_enter();
+ membar_acquire();
ok = ppsratecheck(>rl_lasttime, >rl_curpps, r->rl_maxpps);
- membar_exit();
- r->rl_lock = 0;
+ atomic_store_release(>rl_lock, 0);
out: if (!ok)
atomic_store_relaxed(>missed, 1);
