diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 02bc8feca7740da121b7399e0eaab9286a7931c7..1545f03656c94f76ec2cb5c4b703300f8da88666 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -818,7 +818,7 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
<tbody>
<row>
- <entry morerows="57"><literal>LWLock</></entry>
+ <entry morerows="58"><literal>LWLock</></entry>
<entry><literal>ShmemIndexLock</></entry>
<entry>Waiting to find or allocate space in shared memory.</entry>
</row>
@@ -1069,6 +1069,10 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
<entry><literal>predicate_lock_manager</></entry>
<entry>Waiting to add or examine predicate lock information.</entry>
</row>
+ <row>
+ <entry><literal>parallel_query_dsa</></entry>
+ <entry>Waiting for parallel query dynamic shared memory allocation lock.</entry>
+ </row>
<row>
<entry morerows="9"><literal>Lock</></entry>
<entry><literal>relation</></entry>
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index f9c85989d82b285e50d3282fdd676f41161e2ec4..8a6f844e352b52c3b2023b418719c4d0b469f9ff 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -34,6 +34,7 @@
#include "optimizer/planner.h"
#include "storage/spin.h"
#include "tcop/tcopprot.h"
+#include "utils/dsa.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
@@ -47,6 +48,7 @@
#define PARALLEL_KEY_BUFFER_USAGE UINT64CONST(0xE000000000000003)
#define PARALLEL_KEY_TUPLE_QUEUE UINT64CONST(0xE000000000000004)
#define PARALLEL_KEY_INSTRUMENTATION UINT64CONST(0xE000000000000005)
+#define PARALLEL_KEY_DSA UINT64CONST(0xE000000000000006)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
@@ -345,6 +347,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate, int nworkers)
int param_len;
int instrumentation_len = 0;
int instrument_offset = 0;
+ Size dsa_minsize = dsa_minimum_size();
/* Allocate object for return value. */
pei = palloc0(sizeof(ParallelExecutorInfo));
@@ -413,6 +416,10 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate, int nworkers)
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
+ /* Estimate space for DSA area. */
+ shm_toc_estimate_chunk(&pcxt->estimator, dsa_minsize);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/* Everyone's had a chance to ask for space, so now create the DSM. */
InitializeParallelDSM(pcxt);
@@ -466,6 +473,29 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate, int nworkers)
pei->instrumentation = instrumentation;
}
+ /*
+ * Create a DSA area that can be used by the leader and all workers.
+ * (However, if we failed to create a DSM and are using private memory
+ * instead, then skip this.)
+ */
+ if (pcxt->seg != NULL)
+ {
+ char *area_space;
+
+ area_space = shm_toc_allocate(pcxt->toc, dsa_minsize);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_DSA, area_space);
+ pei->area = dsa_create_in_place(area_space, dsa_minsize,
+ LWTRANCHE_PARALLEL_QUERY_DSA,
+ "parallel_query_dsa",
+ pcxt->seg);
+ }
+
+ /*
+ * Make the area available to executor nodes running in the leader. See
+ * also ParallelQueryMain which makes it available to workers.
+ */
+ estate->es_query_dsa = pei->area;
+
/*
* Give parallel-aware nodes a chance to initialize their shared data.
* This also initializes the elements of instrumentation->ps_instrument,
@@ -571,6 +601,11 @@ ExecParallelFinish(ParallelExecutorInfo *pei)
void
ExecParallelCleanup(ParallelExecutorInfo *pei)
{
+ if (pei->area != NULL)
+ {
+ dsa_detach(pei->area);
+ pei->area = NULL;
+ }
if (pei->pcxt != NULL)
{
DestroyParallelContext(pei->pcxt);
@@ -728,6 +763,8 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
QueryDesc *queryDesc;
SharedExecutorInstrumentation *instrumentation;
int instrument_options = 0;
+ void *area_space;
+ dsa_area *area;
/* Set up DestReceiver, SharedExecutorInstrumentation, and QueryDesc. */
receiver = ExecParallelGetReceiver(seg, toc);
@@ -739,10 +776,21 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
/* Prepare to track buffer usage during query execution. */
InstrStartParallelQuery();
- /* Start up the executor, have it run the plan, and then shut it down. */
+ /* Attach to the dynamic shared memory area. */
+ area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA);
+ area = dsa_attach_in_place(area_space, seg);
+
+ /* Start up the executor */
ExecutorStart(queryDesc, 0);
+
+ /* Special executor initialization steps for parallel workers */
+ queryDesc->planstate->state->es_query_dsa = area;
ExecParallelInitializeWorker(queryDesc->planstate, toc);
+
+ /* Run the plan */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
+
+ /* Shut down the executor */
ExecutorFinish(queryDesc);
/* Report buffer usage during parallel execution. */
@@ -758,6 +806,7 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
ExecutorEnd(queryDesc);
/* Cleanup. */
+ dsa_detach(area);
FreeQueryDesc(queryDesc);
(*receiver->rDestroy) (receiver);
}
diff --git a/src/include/executor/execParallel.h b/src/include/executor/execParallel.h
index f4c6d37a119289ee832d49fd93579fb2e5913bb4..4bbee691a7f33f64c3c8d69fea8d186b1ca2521f 100644
--- a/src/include/executor/execParallel.h
+++ b/src/include/executor/execParallel.h
@@ -17,6 +17,7 @@
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
+#include "utils/dsa.h"
typedef struct SharedExecutorInstrumentation SharedExecutorInstrumentation;
@@ -27,6 +28,7 @@ typedef struct ParallelExecutorInfo
BufferUsage *buffer_usage;
SharedExecutorInstrumentation *instrumentation;
shm_mq_handle **tqueue;
+ dsa_area *area;
bool finished;
} ParallelExecutorInfo;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 703604ab9d746f4f1b2010c3187bcc6d052fe5e8..5c3b8683f5b6dd123fec24e042b6e41f3d17fb6c 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -427,6 +427,9 @@ typedef struct EState
HeapTuple *es_epqTuple; /* array of EPQ substitute tuples */
bool *es_epqTupleSet; /* true if EPQ tuple is provided */
bool *es_epqScanDone; /* true if EPQ tuple has been fetched */
+
+ /* The per-query shared memory area to use for parallel execution. */
+ struct dsa_area *es_query_dsa;
} EState;
diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index db1c687e21e8398bb201666b833c5eb6991d82e5..3ca4db0a7231e0333a5762a22e1d7916599aebd7 100644
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -210,6 +210,7 @@ typedef enum BuiltinTrancheIds
LWTRANCHE_BUFFER_MAPPING,
LWTRANCHE_LOCK_MANAGER,
LWTRANCHE_PREDICATE_LOCK_MANAGER,
+ LWTRANCHE_PARALLEL_QUERY_DSA,
LWTRANCHE_FIRST_USER_DEFINED
} BuiltinTrancheIds;