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Diffstat (limited to 'src/backend/storage/freespace/freespace.c')
-rw-r--r--src/backend/storage/freespace/freespace.c121
1 files changed, 87 insertions, 34 deletions
diff --git a/src/backend/storage/freespace/freespace.c b/src/backend/storage/freespace/freespace.c
index 62e5252aac1..3309ba11dac 100644
--- a/src/backend/storage/freespace/freespace.c
+++ b/src/backend/storage/freespace/freespace.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.54 2006/07/14 14:52:22 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.55 2006/09/21 20:31:22 tgl Exp $
*
*
* NOTES:
@@ -24,7 +24,7 @@
* behavior keeps track of which relation is least recently used.
*
* For each known relation, we track the average request size given to
- * GetPageWithFreeSpace() as well as the most recent number of pages given
+ * GetPageWithFreeSpace() as well as the most recent number of pages reported
* to RecordRelationFreeSpace(). The average request size is not directly
* used in this module, but we expect VACUUM to use it to filter out
* uninteresting amounts of space before calling RecordRelationFreeSpace().
@@ -82,7 +82,7 @@
* relfilenode
* isIndex
* avgRequest
- * lastPageCount
+ * interestingPages
* storedPages
* arena data array of storedPages FSMPageData or IndexFSMPageData
*----------
@@ -111,7 +111,7 @@ typedef struct FsmCacheRelHeader
RelFileNode key; /* hash key (must be first) */
bool isIndex; /* if true, we store only page numbers */
uint32 avgRequest; /* moving average of space requests */
- int32 lastPageCount; /* pages passed to RecordRelationFreeSpace */
+ BlockNumber interestingPages; /* # of pages with useful free space */
int32 storedPages; /* # of pages stored in arena */
} FsmCacheRelHeader;
@@ -128,7 +128,8 @@ static void CheckFreeSpaceMapStatistics(int elevel, int numRels,
static FSMRelation *lookup_fsm_rel(RelFileNode *rel);
static FSMRelation *create_fsm_rel(RelFileNode *rel);
static void delete_fsm_rel(FSMRelation *fsmrel);
-static int realloc_fsm_rel(FSMRelation *fsmrel, int nPages, bool isIndex);
+static int realloc_fsm_rel(FSMRelation *fsmrel, BlockNumber interestingPages,
+ bool isIndex);
static void link_fsm_rel_usage(FSMRelation *fsmrel);
static void unlink_fsm_rel_usage(FSMRelation *fsmrel);
static void link_fsm_rel_storage(FSMRelation *fsmrel);
@@ -146,6 +147,7 @@ static void pack_incoming_pages(FSMPageData *newLocation, int newPages,
static void pack_existing_pages(FSMPageData *newLocation, int newPages,
FSMPageData *oldLocation, int oldPages);
static int fsm_calc_request(FSMRelation *fsmrel);
+static int fsm_calc_request_unclamped(FSMRelation *fsmrel);
static int fsm_calc_target_allocation(int myRequest);
static int fsm_current_chunks(FSMRelation *fsmrel);
static int fsm_current_allocation(FSMRelation *fsmrel);
@@ -361,11 +363,17 @@ GetAvgFSMRequestSize(RelFileNode *rel)
*
* Any pre-existing info about the relation is assumed obsolete and discarded.
*
+ * interestingPages is the total number of pages in the relation that have
+ * at least threshold free space; nPages is the number actually reported in
+ * pageSpaces[] (may be less --- in particular, callers typically clamp their
+ * space usage to MaxFSMPages).
+ *
* The given pageSpaces[] array must be sorted in order by blkno. Note that
* the FSM is at liberty to discard some or all of the data.
*/
void
RecordRelationFreeSpace(RelFileNode *rel,
+ BlockNumber interestingPages,
int nPages,
PageFreeSpaceInfo *pageSpaces)
{
@@ -392,7 +400,7 @@ RecordRelationFreeSpace(RelFileNode *rel,
int curAllocPages;
FSMPageData *newLocation;
- curAlloc = realloc_fsm_rel(fsmrel, nPages, false);
+ curAlloc = realloc_fsm_rel(fsmrel, interestingPages, false);
curAllocPages = curAlloc * CHUNKPAGES;
/*
@@ -455,6 +463,7 @@ GetFreeIndexPage(RelFileNode *rel)
*/
void
RecordIndexFreeSpace(RelFileNode *rel,
+ BlockNumber interestingPages,
int nPages,
BlockNumber *pages)
{
@@ -481,7 +490,7 @@ RecordIndexFreeSpace(RelFileNode *rel,
int i;
IndexFSMPageData *newLocation;
- curAlloc = realloc_fsm_rel(fsmrel, nPages, true);
+ curAlloc = realloc_fsm_rel(fsmrel, interestingPages, true);
curAllocPages = curAlloc * INDEXCHUNKPAGES;
/*
@@ -530,7 +539,7 @@ FreeSpaceMapTruncateRel(RelFileNode *rel, BlockNumber nblocks)
(void) lookup_fsm_page_entry(fsmrel, nblocks, &pageIndex);
/* Delete all such entries */
fsmrel->storedPages = pageIndex;
- /* XXX should we adjust rel's lastPageCount and sumRequests? */
+ /* XXX should we adjust rel's interestingPages and sumRequests? */
}
LWLockRelease(FreeSpaceLock);
}
@@ -587,20 +596,24 @@ PrintFreeSpaceMapStatistics(int elevel)
{
FSMRelation *fsmrel;
int storedPages = 0;
+ double sumRequests = 0;
int numRels;
- double sumRequests;
double needed;
LWLockAcquire(FreeSpaceLock, LW_EXCLUSIVE);
- /* Count total space used --- tedious, but seems useful */
+ /*
+ * Count total space actually used, as well as the unclamped request total
+ */
for (fsmrel = FreeSpaceMap->firstRel;
fsmrel != NULL;
fsmrel = fsmrel->nextPhysical)
+ {
storedPages += fsmrel->storedPages;
+ sumRequests += fsm_calc_request_unclamped(fsmrel);
+ }
/* Copy other stats before dropping lock */
numRels = FreeSpaceMap->numRels;
- sumRequests = FreeSpaceMap->sumRequests;
LWLockRelease(FreeSpaceLock);
/* Convert stats to actual number of page slots needed */
@@ -613,7 +626,8 @@ PrintFreeSpaceMapStatistics(int elevel)
"%.0f page slots are required to track all free space.\n"
"Current limits are: %d page slots, %d relations, using %.0f KB.",
Min(needed, MaxFSMPages),
- needed, MaxFSMPages, MaxFSMRelations,
+ needed,
+ MaxFSMPages, MaxFSMRelations,
(double) FreeSpaceShmemSize() / 1024.0)));
CheckFreeSpaceMapStatistics(NOTICE, numRels, needed);
@@ -687,7 +701,7 @@ DumpFreeSpaceMap(int code, Datum arg)
relheader.key = fsmrel->key;
relheader.isIndex = fsmrel->isIndex;
relheader.avgRequest = fsmrel->avgRequest;
- relheader.lastPageCount = fsmrel->lastPageCount;
+ relheader.interestingPages = fsmrel->interestingPages;
relheader.storedPages = fsmrel->storedPages;
if (fwrite(&relheader, 1, sizeof(relheader), fp) != sizeof(relheader))
goto write_failed;
@@ -792,17 +806,12 @@ LoadFreeSpaceMap(void)
if (fread(&relheader, 1, sizeof(relheader), fp) != sizeof(relheader) ||
(relheader.isIndex != false && relheader.isIndex != true) ||
relheader.avgRequest >= BLCKSZ ||
- relheader.lastPageCount < 0 ||
relheader.storedPages < 0)
{
elog(LOG, "bogus rel header in \"%s\"", FSM_CACHE_FILENAME);
goto read_failed;
}
- /* Make sure lastPageCount doesn't exceed current MaxFSMPages */
- if (relheader.lastPageCount > MaxFSMPages)
- relheader.lastPageCount = MaxFSMPages;
-
/* Read the per-page data */
nPages = relheader.storedPages;
if (relheader.isIndex)
@@ -827,7 +836,7 @@ LoadFreeSpaceMap(void)
fsmrel = create_fsm_rel(&relheader.key);
fsmrel->avgRequest = relheader.avgRequest;
- curAlloc = realloc_fsm_rel(fsmrel, relheader.lastPageCount,
+ curAlloc = realloc_fsm_rel(fsmrel, relheader.interestingPages,
relheader.isIndex);
if (relheader.isIndex)
{
@@ -932,7 +941,7 @@ create_fsm_rel(RelFileNode *rel)
/* New hashtable entry, initialize it (hash_search set the key) */
fsmrel->isIndex = false; /* until we learn different */
fsmrel->avgRequest = INITIAL_AVERAGE;
- fsmrel->lastPageCount = 0;
+ fsmrel->interestingPages = 0;
fsmrel->firstChunk = -1; /* no space allocated */
fsmrel->storedPages = 0;
fsmrel->nextPage = 0;
@@ -988,7 +997,8 @@ delete_fsm_rel(FSMRelation *fsmrel)
* The return value is the actual new allocation, in chunks.
*/
static int
-realloc_fsm_rel(FSMRelation *fsmrel, int nPages, bool isIndex)
+realloc_fsm_rel(FSMRelation *fsmrel, BlockNumber interestingPages,
+ bool isIndex)
{
int myRequest;
int myAlloc;
@@ -999,7 +1009,7 @@ realloc_fsm_rel(FSMRelation *fsmrel, int nPages, bool isIndex)
*/
fsmrel->storedPages = 0;
FreeSpaceMap->sumRequests -= fsm_calc_request(fsmrel);
- fsmrel->lastPageCount = nPages;
+ fsmrel->interestingPages = interestingPages;
fsmrel->isIndex = isIndex;
myRequest = fsm_calc_request(fsmrel);
FreeSpaceMap->sumRequests += myRequest;
@@ -1012,7 +1022,7 @@ realloc_fsm_rel(FSMRelation *fsmrel, int nPages, bool isIndex)
* new data in-place.
*/
curAlloc = fsm_current_allocation(fsmrel);
- if (myAlloc > curAlloc && (myRequest + 1) > curAlloc && nPages > 0)
+ if (myAlloc > curAlloc && (myRequest + 1) > curAlloc && interestingPages > 0)
{
/* Remove entry from storage list, and compact */
unlink_fsm_rel_storage(fsmrel);
@@ -1649,27 +1659,70 @@ pack_existing_pages(FSMPageData *newLocation, int newPages,
}
/*
- * Calculate number of chunks "requested" by a rel.
+ * Calculate number of chunks "requested" by a rel. The "request" is
+ * anything beyond the rel's one guaranteed chunk.
*
- * Rel's lastPageCount and isIndex settings must be up-to-date when called.
+ * Rel's interestingPages and isIndex settings must be up-to-date when called.
*
* See notes at top of file for details.
*/
static int
fsm_calc_request(FSMRelation *fsmrel)
{
- int chunkCount;
+ int req;
/* Convert page count to chunk count */
if (fsmrel->isIndex)
- chunkCount = (fsmrel->lastPageCount - 1) / INDEXCHUNKPAGES + 1;
+ {
+ /* test to avoid unsigned underflow at zero */
+ if (fsmrel->interestingPages <= INDEXCHUNKPAGES)
+ return 0;
+ /* quotient will fit in int, even if interestingPages doesn't */
+ req = (fsmrel->interestingPages - 1) / INDEXCHUNKPAGES;
+ }
else
- chunkCount = (fsmrel->lastPageCount - 1) / CHUNKPAGES + 1;
- /* "Request" is anything beyond our one guaranteed chunk */
- if (chunkCount <= 0)
- return 0;
+ {
+ if (fsmrel->interestingPages <= CHUNKPAGES)
+ return 0;
+ req = (fsmrel->interestingPages - 1) / CHUNKPAGES;
+ }
+
+ /*
+ * We clamp the per-relation requests to at most half the arena size;
+ * this is intended to prevent a single bloated relation from crowding
+ * out FSM service for every other rel.
+ */
+ req = Min(req, FreeSpaceMap->totalChunks / 2);
+
+ return req;
+}
+
+/*
+ * Same as above, but without the clamp ... this is just intended for
+ * reporting the total space needed to store all information.
+ */
+static int
+fsm_calc_request_unclamped(FSMRelation *fsmrel)
+{
+ int req;
+
+ /* Convert page count to chunk count */
+ if (fsmrel->isIndex)
+ {
+ /* test to avoid unsigned underflow at zero */
+ if (fsmrel->interestingPages <= INDEXCHUNKPAGES)
+ return 0;
+ /* quotient will fit in int, even if interestingPages doesn't */
+ req = (fsmrel->interestingPages - 1) / INDEXCHUNKPAGES;
+ }
else
- return chunkCount - 1;
+ {
+ if (fsmrel->interestingPages <= CHUNKPAGES)
+ return 0;
+ req = (fsmrel->interestingPages - 1) / CHUNKPAGES;
+ }
+
+ return req;
}
/*
@@ -1769,11 +1822,11 @@ DumpFreeSpace(void)
for (fsmrel = FreeSpaceMap->usageList; fsmrel; fsmrel = fsmrel->nextUsage)
{
relNum++;
- fprintf(stderr, "Map %d: rel %u/%u/%u isIndex %d avgRequest %u lastPageCount %d nextPage %d\nMap= ",
+ fprintf(stderr, "Map %d: rel %u/%u/%u isIndex %d avgRequest %u interestingPages %u nextPage %d\nMap= ",
relNum,
fsmrel->key.spcNode, fsmrel->key.dbNode, fsmrel->key.relNode,
(int) fsmrel->isIndex, fsmrel->avgRequest,
- fsmrel->lastPageCount, fsmrel->nextPage);
+ fsmrel->interestingPages, fsmrel->nextPage);
if (fsmrel->isIndex)
{
IndexFSMPageData *page;
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 11:51:35 +0000