diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 33 | ||||
| -rw-r--r-- | src/include/pg_config.h.in | 3 | ||||
| -rw-r--r-- | src/include/pg_config_manual.h | 14 |
3 files changed, 26 insertions, 24 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index daea9fafdfb..9a2b3308b1e 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.326 2009/01/01 17:23:36 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.327 2009/01/11 18:02:17 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -17,6 +17,7 @@ #include <ctype.h> #include <signal.h> #include <time.h> +#include <fcntl.h> #include <sys/stat.h> #include <sys/time.h> #include <sys/wait.h> @@ -2436,29 +2437,17 @@ XLogFileClose(void) Assert(openLogFile >= 0); /* - * posix_fadvise is problematic on many platforms: on older x86 Linux it - * just dumps core, and there are reports of problems on PPC platforms as - * well. The following is therefore disabled for the time being. We could - * consider some kind of configure test to see if it's safe to use, but - * since we lack hard evidence that there's any useful performance gain to - * be had, spending time on that seems unprofitable for now. - */ -#ifdef NOT_USED - - /* * WAL segment files will not be re-read in normal operation, so we advise - * OS to release any cached pages. But do not do so if WAL archiving is - * active, because archiver process could use the cache to read the WAL - * segment. - * - * While O_DIRECT works for O_SYNC, posix_fadvise() works for fsync() and - * O_SYNC, and some platforms only have posix_fadvise(). - */ -#if defined(HAVE_DECL_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED) - if (!XLogArchivingActive()) - posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED); + * the OS to release any cached pages. But do not do so if WAL archiving + * is active, because archiver process could use the cache to read the WAL + * segment. Also, don't bother with it if we are using O_DIRECT, since + * the kernel is presumably not caching in that case. + */ +#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED) + if (!XLogArchivingActive() && + (get_sync_bit(sync_method) & PG_O_DIRECT) == 0) + (void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED); #endif -#endif /* NOT_USED */ if (close(openLogFile)) ereport(PANIC, diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 308f2bb6a31..3cc7c7ce6a8 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -336,6 +336,9 @@ /* Define to 1 if you have the <poll.h> header file. */ #undef HAVE_POLL_H +/* Define to 1 if you have the `posix_fadvise' function. */ +#undef HAVE_POSIX_FADVISE + /* Define to 1 if you have the POSIX signal interface. */ #undef HAVE_POSIX_SIGNALS diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h index 3c1c1c0b8e6..ff9d6ce45de 100644 --- a/src/include/pg_config_manual.h +++ b/src/include/pg_config_manual.h @@ -6,7 +6,7 @@ * for developers. If you edit any of these, be sure to do a *full* * rebuild (and an initdb if noted). * - * $PostgreSQL: pgsql/src/include/pg_config_manual.h,v 1.35 2008/07/12 02:28:43 tgl Exp $ + * $PostgreSQL: pgsql/src/include/pg_config_manual.h,v 1.36 2009/01/11 18:02:17 tgl Exp $ *------------------------------------------------------------------------ */ @@ -112,7 +112,7 @@ #define ALIGNOF_BUFFER 32 /* - * Disable UNIX sockets for those operating system. + * Disable UNIX sockets for certain operating systems. */ #if defined(WIN32) #undef HAVE_UNIX_SOCKETS @@ -126,6 +126,16 @@ #endif /* + * USE_POSIX_FADVISE controls whether Postgres will attempt to use the + * posix_fadvise() kernel call. Usually the automatic configure tests are + * sufficient, but some older Linux distributions had broken versions of + * posix_fadvise(). If necessary you can remove the #define here. + */ +#if HAVE_DECL_POSIX_FADVISE && defined(HAVE_POSIX_FADVISE) +#define USE_POSIX_FADVISE +#endif + +/* * This is the default directory in which AF_UNIX socket files are * placed. Caution: changing this risks breaking your existing client * applications, which are likely to continue to look in the old |