diff --git a/contrib/pg_buffercache/Makefile b/contrib/pg_buffercache/Makefile index 065d3d6..8813c50 100644 --- a/contrib/pg_buffercache/Makefile +++ b/contrib/pg_buffercache/Makefile @@ -4,7 +4,7 @@ MODULE_big = pg_buffercache OBJS = pg_buffercache_pages.o $(WIN32RES) EXTENSION = pg_buffercache -DATA = pg_buffercache--1.1.sql pg_buffercache--1.0--1.1.sql pg_buffercache--unpackaged--1.0.sql +DATA = pg_buffercache--1.2.sql pg_buffercache--1.1--1.2.sql pg_buffercache--1.0--1.1.sql pg_buffercache--unpackaged--1.0.sql PGFILEDESC = "pg_buffercache - monitoring of shared buffer cache in real-time" ifdef USE_PGXS diff --git a/contrib/pg_buffercache/README b/contrib/pg_buffercache/README new file mode 100644 index 0000000..35a7607 --- /dev/null +++ b/contrib/pg_buffercache/README @@ -0,0 +1,3 @@ +In version pg_buffercache--1.2 been added parameter (consistent = cons and semiconsistent = semicons) + +semiconsistent pg_buffercache works 10% faster and use LWLock free algorithm diff --git a/contrib/pg_buffercache/pg_buffercache--1.1--1.2.sql b/contrib/pg_buffercache/pg_buffercache--1.1--1.2.sql new file mode 100644 index 0000000..cd50f93 --- /dev/null +++ b/contrib/pg_buffercache/pg_buffercache--1.1--1.2.sql @@ -0,0 +1,27 @@ +/* contrib/pg_buffercache/pg_buffercache--1.1--1.2.sql */ + +-- complain if script is sourced in psql, rather than via ALTER EXTENSION +\echo Use "ALTER EXTENSION pg_buffercache(text) UPDATE TO '1.2'" to load this file. \quit + +-- Register the function. +CREATE FUNCTION pg_buffercache_pages(mode text) +RETURNS SETOF RECORD +AS 'MODULE_PATHNAME', 'pg_buffercache_pages' +LANGUAGE C; + +-- Make special type pg_buffercache +create type tbuffercache as + (bufferid integer, relfilenode oid, + reltablespace oid, reldatabase oid, + relforknumber int2, relblocknumber int8, + isdirty bool, usagecount int2, pinning_backends int4); + +-- Create a function for convenient access. +create function pg_buffercache(mod text) +returns setof tbuffercache +as 'SELECT * FROM pg_buffercache_pages(mod) AS (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, pinning_backends int4);' +language 'sql'; + +-- Don't want these to be available to public. +REVOKE ALL ON FUNCTION pg_buffercache_pages(text) FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_buffercache(text) FROM PUBLIC; diff --git a/contrib/pg_buffercache/pg_buffercache--1.1.sql b/contrib/pg_buffercache/pg_buffercache--1.1.sql deleted file mode 100644 index f3b6482..0000000 --- a/contrib/pg_buffercache/pg_buffercache--1.1.sql +++ /dev/null @@ -1,21 +0,0 @@ -/* contrib/pg_buffercache/pg_buffercache--1.1.sql */ - --- complain if script is sourced in psql, rather than via CREATE EXTENSION -\echo Use "CREATE EXTENSION pg_buffercache" to load this file. \quit - --- Register the function. -CREATE FUNCTION pg_buffercache_pages() -RETURNS SETOF RECORD -AS 'MODULE_PATHNAME', 'pg_buffercache_pages' -LANGUAGE C; - --- Create a view for convenient access. -CREATE VIEW pg_buffercache AS - SELECT P.* FROM pg_buffercache_pages() AS P - (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, - relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, - pinning_backends int4); - --- Don't want these to be available to public. -REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC; -REVOKE ALL ON pg_buffercache FROM PUBLIC; diff --git a/contrib/pg_buffercache/pg_buffercache--1.2.sql b/contrib/pg_buffercache/pg_buffercache--1.2.sql new file mode 100644 index 0000000..23d7b7d --- /dev/null +++ b/contrib/pg_buffercache/pg_buffercache--1.2.sql @@ -0,0 +1,50 @@ +/* contrib/pg_buffercache/pg_buffercache--1.2.sql */ + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION pg_buffercache" to load this file. \quit + +-- Register the function. +CREATE FUNCTION pg_buffercache_pages() +RETURNS SETOF RECORD +AS 'MODULE_PATHNAME', 'pg_buffercache_pages' +LANGUAGE C; +CREATE FUNCTION pg_buffercache_pages(mode text) +RETURNS SETOF RECORD +AS 'MODULE_PATHNAME', 'pg_buffercache_pages' +LANGUAGE C; + +-- Make special type pg_buffercache +create type tbuffercache as + (bufferid integer, relfilenode oid, + reltablespace oid, reldatabase oid, + relforknumber int2, relblocknumber int8, + isdirty bool, usagecount int2, pinning_backends int4); + +-- Create a view for convenient access. +CREATE VIEW pg_buffercache AS + SELECT P.* FROM pg_buffercache_pages() AS P + (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, + relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, + pinning_backends int4); + +CREATE VIEW pg_buffercache_cons AS SELECT P.* FROM pg_buffercache_pages('cons') AS P (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2,pinning_backends int4); + +CREATE VIEW pg_buffercache_noncons AS SELECT P.* FROM pg_buffercache_pages('noncons') AS P (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2,pinning_backends int4); + +CREATE VIEW pg_buffercache_semicons AS SELECT P.* FROM pg_buffercache_pages('semicons') AS P (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2,pinning_backends int4); + +-- Create a function for convenient access. +create function pg_buffercache(mod text) +returns setof tbuffercache +as 'SELECT * FROM pg_buffercache_pages(mod) AS (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, pinning_backends int4);' +language 'sql'; + +-- Don't want these to be available to public. +REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC; +REVOKE ALL ON pg_buffercache FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_buffercache_pages(text) FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_buffercache(text) FROM PUBLIC; + +REVOKE ALL ON pg_buffercache_cons FROM PUBLIC; +REVOKE ALL ON pg_buffercache_noncons FROM PUBLIC; +REVOKE ALL ON pg_buffercache_semicons FROM PUBLIC; diff --git a/contrib/pg_buffercache/pg_buffercache.control b/contrib/pg_buffercache/pg_buffercache.control index 5494e2f..a4d664f 100644 --- a/contrib/pg_buffercache/pg_buffercache.control +++ b/contrib/pg_buffercache/pg_buffercache.control @@ -1,5 +1,5 @@ # pg_buffercache extension comment = 'examine the shared buffer cache' -default_version = '1.1' +default_version = '1.2' module_pathname = '$libdir/pg_buffercache' relocatable = true diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c index 17b4b6f..0175936 100644 --- a/contrib/pg_buffercache/pg_buffercache_pages.c +++ b/contrib/pg_buffercache/pg_buffercache_pages.c @@ -53,6 +53,15 @@ typedef struct BufferCachePagesRec *record; } BufferCachePagesContext; +/* + * Struct for consistency control + */ +typedef enum +{ + CONS_SNAP, + SEMICONS_SNAP, + NONCONS_SNAP +} ConsistencyType; /* * Function returning data from the shared buffer cache - buffer number, @@ -70,10 +79,37 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) TupleDesc tupledesc; TupleDesc expected_tupledesc; HeapTuple tuple; + int num_partit = 1; /* Number of partition. */ + ConsistencyType snaptype = CONS_SNAP; /* Flag for consistency control. */ + + if (PG_NARGS() > 0) + { + text *type = PG_GETARG_TEXT_P(0); + + if (VARSIZE_ANY_EXHDR(type) == 4 && + strncmp(VARDATA(type), "cons", 4) == 0) + snaptype = CONS_SNAP; + else if (VARSIZE_ANY_EXHDR(type) == 8 && + strncmp(VARDATA(type), "semicons", 8) == 0) + { + snaptype = SEMICONS_SNAP; + num_partit = NUM_BUFFER_PARTITIONS; + } + else if (VARSIZE_ANY_EXHDR(type) == 7 && + strncmp(VARDATA(type), "noncons", 7) == 0) + snaptype = NONCONS_SNAP; + else + { + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid consistency type"), + errhint("Valid consistency types are \"cons\", \"semicons\" and \"noncons\"."))); + PG_RETURN_INT64(0); /* Placate compiler. */ + } if (SRF_IS_FIRSTCALL()) { - int i; + int i, j = 1; funcctx = SRF_FIRSTCALL_INIT(); @@ -138,55 +174,69 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) * partitions of the buffer map. Needless to say, this is horrible * for concurrency. Must grab locks in increasing order to avoid * possible deadlocks. + * So there is alternative by LWlock free and one partition Lock method + * respectively named Nonconcistent and Semiconsistent */ - for (i = 0; i < NUM_BUFFER_PARTITIONS; i++) - LWLockAcquire(BufMappingPartitionLockByIndex(i), LW_SHARED); - /* - * Scan through all the buffers, saving the relevant fields in the - * fctx->record structure. - */ - for (i = 0; i < NBuffers; i++) + for (j = 0; j < num_partit; j++) { - BufferDesc *bufHdr; - uint32 buf_state; - - bufHdr = GetBufferDescriptor(i); - /* Lock each buffer header before inspecting. */ - buf_state = LockBufHdr(bufHdr); - - fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr); - fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode; - fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode; - fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode; - fctx->record[i].forknum = bufHdr->tag.forkNum; - fctx->record[i].blocknum = bufHdr->tag.blockNum; - fctx->record[i].usagecount = BUF_STATE_GET_USAGECOUNT(buf_state); - fctx->record[i].pinning_backends = BUF_STATE_GET_REFCOUNT(buf_state); - - if (buf_state & BM_DIRTY) - fctx->record[i].isdirty = true; - else - fctx->record[i].isdirty = false; - - /* Note if the buffer is valid, and has storage created */ - if ((buf_state & BM_VALID) && (buf_state & BM_TAG_VALID)) - fctx->record[i].isvalid = true; - else - fctx->record[i].isvalid = false; - - UnlockBufHdr(bufHdr, buf_state); + if (snaptype == CONS_SNAP) + for (i = 0; i < NUM_BUFFER_PARTITIONS; i++) + LWLockAcquire(BufMappingPartitionLockByIndex(i), LW_SHARED); + else if (snaptype == SEMICONS_SNAP) + LWLockAcquire(BufMappingPartitionLockByIndex(j), LW_SHARED); + + for (i = 0; i < NBuffers; i++) + { + BufferDesc *bufHdr; + uint32 buf_state; + + bufHdr = GetBufferDescriptor(i); + /* Lock each buffer header before inspecting. */ + + if (bufHdr->tag.forkNum == -1) + { + fctx->record[i].blocknum = InvalidBlockNumber; + continue; + } + + buf_state = LockBufHdr(bufHdr); + + fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr); + fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode; + fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode; + fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode; + fctx->record[i].forknum = bufHdr->tag.forkNum; + fctx->record[i].blocknum = bufHdr->tag.blockNum; + fctx->record[i].usagecount = BUF_STATE_GET_USAGECOUNT(buf_state); + fctx->record[i].pinning_backends = BUF_STATE_GET_REFCOUNT(buf_state); + + if (buf_state & BM_DIRTY) + fctx->record[i].isdirty = true; + else + fctx->record[i].isdirty = false; + + /* Note if the buffer is valid, and has storage created */ + if ((buf_state & BM_VALID) && (buf_state & BM_TAG_VALID)) + fctx->record[i].isvalid = true; + else + fctx->record[i].isvalid = false; + + UnlockBufHdr(bufHdr, buf_state); + } + if (snaptype == CONS_SNAP) + for (i = NUM_BUFFER_PARTITIONS; --i >= 0;) + LWLockRelease(BufMappingPartitionLockByIndex(i)); + else if (snaptype == SEMICONS_SNAP) + /* + * And release locks. We do this in reverse order for two reasons: + * (1) Anyone else who needs more than one of the locks will be trying + * to lock them in increasing order; we don't want to release the + * other process until it can get all the locks it needs. (2) This + * avoids O(N^2) behavior inside LWLockRelease. + */ + LWLockRelease(BufMappingPartitionLockByIndex(j)); } - - /* - * And release locks. We do this in reverse order for two reasons: - * (1) Anyone else who needs more than one of the locks will be trying - * to lock them in increasing order; we don't want to release the - * other process until it can get all the locks it needs. (2) This - * avoids O(N^2) behavior inside LWLockRelease. - */ - for (i = NUM_BUFFER_PARTITIONS; --i >= 0;) - LWLockRelease(BufMappingPartitionLockByIndex(i)); } funcctx = SRF_PERCALL_SETUP();