Module Name: src
Committed By: riastradh
Date: Wed Jun 16 21:53:51 UTC 2021
Modified Files:
src/libexec/ld.elf_so: rtld.c
Log Message:
ld.elf_so(1): Omit needless membar_enter.
The use of membar_enter is to separate atomic r/m/w on a lock from
the body of the critical section so two different critical sections
happen in order:
body of previous critical section;
exit critical section:
membar_exit();
atomic_r/m/w(lock stuff);
enter critical section:
atomic_r/m/w(lock stuff);
membar_enter();
body of next critical section;
_rtld_shared_enter does this, but it _also_ issued an extraneous
membar_enter before the atomic_r/m/w part, which doesn't impose any
semantically important order but may cost some performance.
To generate a diff of this commit:
cvs rdiff -u -r1.208 -r1.209 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:1.208 src/libexec/ld.elf_so/rtld.c:1.209
--- src/libexec/ld.elf_so/rtld.c:1.208 Sun May 30 02:26:08 2021
+++ src/libexec/ld.elf_so/rtld.c Wed Jun 16 21:53:51 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: rtld.c,v 1.208 2021/05/30 02:26:08 joerg Exp $ */
+/* $NetBSD: rtld.c,v 1.209 2021/06/16 21:53:51 riastradh Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.208 2021/05/30 02:26:08 joerg Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.209 2021/06/16 21:53:51 riastradh Exp $");
#endif /* not lint */
#include <sys/param.h>
@@ -1673,8 +1673,6 @@ _rtld_shared_enter(void)
unsigned int cur;
lwpid_t waiter, self = 0;
- membar_enter();
-
for (;;) {
cur = _rtld_mutex;
/*
