From ae72283816e7466ee9e7e93c9d36f5f5c362680f Mon Sep 17 00:00:00 2001
From: Neil Conway <neilc@samurai.com>
Date: Fri, 24 Sep 2004 06:29:07 +0000
Subject: [PATCH] Cleanup some ancient Ultrix / Alpha code in main() that is
intended to modify how unaligned memory accesses are dealt with. Document
that this is really what is going on, and merge the NOFIXADE and NOPRINTADE
code paths.
---
src/backend/main/main.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/src/backend/main/main.c b/src/backend/main/main.c
index df9c776b602..bcab85cbc57 100644
--- a/src/backend/main/main.c
+++ b/src/backend/main/main.c
@@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/main/main.c,v 1.89 2004/08/29 05:06:43 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/main/main.c,v 1.90 2004/09/24 06:29:07 neilc Exp $
*
*-------------------------------------------------------------------------
*/
@@ -71,18 +71,23 @@ main(int argc, char *argv[])
#if defined(__alpha) /* no __alpha__ ? */
#ifdef NOFIXADE
- int buffer[] = {SSIN_UACPROC, UAC_SIGBUS};
-#endif /* NOFIXADE */
-#ifdef NOPRINTADE
- int buffer[] = {SSIN_UACPROC, UAC_NOPRINT};
-#endif /* NOPRINTADE */
+ int buffer[] = {SSIN_UACPROC, UAC_SIGBUS | UAC_NOPRINT};
+#endif
#endif /* __alpha */
#ifdef WIN32
char *env_locale;
#endif
-#if defined(NOFIXADE) || defined(NOPRINTADE)
+ /*
+ * On some platforms, unaligned memory accesses result in a kernel
+ * trap; the default kernel behavior is to emulate the memory
+ * access, but this results in a significant performance
+ * penalty. We ought to fix PG not to make such unaligned memory
+ * accesses, so this code disables the kernel emulation: unaligned
+ * accesses will result in SIGBUS instead.
+ */
+#ifdef NOFIXADE
#if defined(ultrix4)
syscall(SYS_sysmips, MIPS_FIXADE, 0, NULL, NULL, NULL);
@@ -94,7 +99,7 @@ main(int argc, char *argv[])
write_stderr("%s: setsysinfo failed: %s\n",
argv[0], strerror(errno));
#endif
-#endif /* NOFIXADE || NOPRINTADE */
+#endif /* NOFIXADE */
#if defined(WIN32)
{
--
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