diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 33 |
1 files changed, 11 insertions, 22 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, |