diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 96 |
1 files changed, 42 insertions, 54 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index ae57ec0231a..a917616cffd 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.215 2005/08/11 21:11:43 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.216 2005/08/20 23:26:10 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -91,31 +91,6 @@ #endif #endif -/* - * Limitation of buffer-alignment for direct io depend on OS and filesystem, - * but BLCKSZ is assumed to be enough for it. - */ -#ifdef O_DIRECT -#define ALIGNOF_XLOG_BUFFER BLCKSZ -#else -#define ALIGNOF_XLOG_BUFFER MAXIMUM_ALIGNOF -#endif - -/* - * Switch the alignment routine because ShmemAlloc() returns a max-aligned - * buffer and ALIGNOF_XLOG_BUFFER may be greater than MAXIMUM_ALIGNOF. - */ -#if ALIGNOF_XLOG_BUFFER <= MAXIMUM_ALIGNOF -#define XLOG_BUFFER_ALIGN(LEN) MAXALIGN((LEN)) -#else -#define XLOG_BUFFER_ALIGN(LEN) ((LEN) + (ALIGNOF_XLOG_BUFFER)) -#endif -/* assume sizeof(ptrdiff_t) == sizeof(void*) */ -#define POINTERALIGN(ALIGNVAL,PTR) \ - ((char *)(((ptrdiff_t) (PTR) + (ALIGNVAL-1)) & ~((ptrdiff_t) (ALIGNVAL-1)))) -#define XLOG_BUFFER_POINTERALIGN(PTR) \ - POINTERALIGN((ALIGNOF_XLOG_BUFFER), (PTR)) - #ifdef OPEN_DATASYNC_FLAG #define DEFAULT_SYNC_METHOD_STR "open_datasync" #define DEFAULT_SYNC_METHOD SYNC_METHOD_OPEN @@ -135,6 +110,17 @@ #endif +/* + * Limitation of buffer-alignment for direct IO depends on OS and filesystem, + * but BLCKSZ is assumed to be enough for it. + */ +#ifdef O_DIRECT +#define ALIGNOF_XLOG_BUFFER BLCKSZ +#else +#define ALIGNOF_XLOG_BUFFER ALIGNOF_BUFFER +#endif + + /* File path names (all relative to $PGDATA) */ #define BACKUP_LABEL_FILE "backup_label" #define RECOVERY_COMMAND_FILE "recovery.conf" @@ -173,8 +159,6 @@ static int open_sync_bit = DEFAULT_SYNC_FLAGBIT; #define XLOG_SYNC_BIT (enableFsync ? open_sync_bit : 0) -#define MinXLOGbuffers 4 - /* * ThisTimeLineID will be same in all backends --- it identifies current @@ -3615,16 +3599,27 @@ UpdateControlFile(void) /* * Initialization of shared memory for XLOG */ - -int +Size XLOGShmemSize(void) { - if (XLOGbuffers < MinXLOGbuffers) - XLOGbuffers = MinXLOGbuffers; + Size size; - return XLOG_BUFFER_ALIGN(sizeof(XLogCtlData) + sizeof(XLogRecPtr) * XLOGbuffers) - + BLCKSZ * XLOGbuffers + - MAXALIGN(sizeof(ControlFileData)); + /* XLogCtl */ + size = sizeof(XLogCtlData); + /* xlblocks array */ + size = add_size(size, mul_size(sizeof(XLogRecPtr), XLOGbuffers)); + /* extra alignment padding for XLOG I/O buffers */ + size = add_size(size, ALIGNOF_XLOG_BUFFER); + /* and the buffers themselves */ + size = add_size(size, mul_size(BLCKSZ, XLOGbuffers)); + + /* + * Note: we don't count ControlFileData, it comes out of the "slop + * factor" added by CreateSharedMemoryAndSemaphores. This lets us + * use this routine again below to compute the actual allocation size. + */ + + return size; } void @@ -3632,17 +3627,10 @@ XLOGShmemInit(void) { bool foundXLog, foundCFile; - - /* this must agree with space requested by XLOGShmemSize() */ - if (XLOGbuffers < MinXLOGbuffers) - XLOGbuffers = MinXLOGbuffers; + char *allocptr; XLogCtl = (XLogCtlData *) - ShmemInitStruct("XLOG Ctl", - XLOG_BUFFER_ALIGN(sizeof(XLogCtlData) + - sizeof(XLogRecPtr) * XLOGbuffers) - + BLCKSZ * XLOGbuffers, - &foundXLog); + ShmemInitStruct("XLOG Ctl", XLOGShmemSize(), &foundXLog); ControlFile = (ControlFileData *) ShmemInitStruct("Control File", sizeof(ControlFileData), &foundCFile); @@ -3660,17 +3648,16 @@ XLOGShmemInit(void) * a multiple of the alignment for same, so no extra alignment padding * is needed here. */ - XLogCtl->xlblocks = (XLogRecPtr *) - (((char *) XLogCtl) + sizeof(XLogCtlData)); + allocptr = ((char *) XLogCtl) + sizeof(XLogCtlData); + XLogCtl->xlblocks = (XLogRecPtr *) allocptr; memset(XLogCtl->xlblocks, 0, sizeof(XLogRecPtr) * XLOGbuffers); + allocptr += sizeof(XLogRecPtr) * XLOGbuffers; /* - * Here, on the other hand, we must MAXALIGN to ensure the page - * buffers have worst-case alignment. + * Align the start of the page buffers to an ALIGNOF_XLOG_BUFFER boundary. */ - XLogCtl->pages = XLOG_BUFFER_POINTERALIGN( - ((char *) XLogCtl) - + sizeof(XLogCtlData) + sizeof(XLogRecPtr) * XLOGbuffers); + allocptr = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, allocptr); + XLogCtl->pages = allocptr; memset(XLogCtl->pages, 0, BLCKSZ * XLOGbuffers); /* @@ -3728,8 +3715,9 @@ BootStrapXLOG(void) /* First timeline ID is always 1 */ ThisTimeLineID = 1; - buffer = (char *) malloc(BLCKSZ + ALIGNOF_XLOG_BUFFER); - page = (XLogPageHeader) XLOG_BUFFER_POINTERALIGN(buffer); + /* page buffer must be aligned suitably for O_DIRECT */ + buffer = (char *) palloc(BLCKSZ + ALIGNOF_XLOG_BUFFER); + page = (XLogPageHeader) TYPEALIGN(ALIGNOF_XLOG_BUFFER, buffer); memset(page, 0, BLCKSZ); /* Set up information for the initial checkpoint record */ @@ -3824,7 +3812,7 @@ BootStrapXLOG(void) BootStrapSUBTRANS(); BootStrapMultiXact(); - free(buffer); + pfree(buffer); } static char * |