From 56deeba7514f9e3e8d91c9d0e5f56d206f1ec663 Mon Sep 17 00:00:00 2001 From: Florents Tselai Date: Tue, 8 Jul 2025 14:06:57 +0300 Subject: [PATCH v5] Update pg_dsm_registry_allocations to include stuff added in fe07100 --- doc/src/sgml/system-views.sgml | 84 +++++++++++++++++++ src/backend/catalog/system_views.sql | 8 ++ src/backend/storage/ipc/dsm_registry.c | 66 +++++++++++++++ src/include/catalog/pg_proc.dat | 6 ++ .../expected/test_dsm_registry.out | 9 ++ .../sql/test_dsm_registry.sql | 2 + src/test/regress/expected/rules.out | 4 + 7 files changed, 179 insertions(+) diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml index e1ac544ee40..c61c6f6b2a7 100644 --- a/doc/src/sgml/system-views.sgml +++ b/doc/src/sgml/system-views.sgml @@ -186,6 +186,11 @@ NUMA node mappings for shared memory allocations + + pg_dsm_registry_allocations + DSM segment allocations registered via the DSM registry + + pg_stats planner statistics @@ -4143,6 +4148,85 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx + + <structname>pg_dsm_registry_allocations</structname> + + + pg_dsm_registry_allocations + + + + The pg_dsm_registry_allocations view shows current + allocations registered in the dynamic shared memory (DSM) registry. This + includes all entries that have been registered and tracked by + PostgreSQL during the server's operation. Entries + may represent a raw dynamic shared memory (DSM) segment, a dynamic shared + memory area (DSA), or a shared hash table (dshash) built on top of a DSA. + + + + This view is useful for monitoring DSM usage by extensions or internal + components using dynamic shared memory segments. + + + + <structname>pg_dsm_registry_allocations</structname> Columns + + + + + Column Type + + + Description + + + + + + + + name text + + + The name of the allocation as registered in the DSM registry. + + + + + + type text + + + The type of allocation. Possible values are dsm for a + raw dynamic shared memory segment, dsa for a dynamic + shared memory area, and dsh for a dynamic shared hash table. + + + + + + size int8 + + + The size of the allocation in bytes. For entries of type dsm, + this reflects the actual size of the allocated DSM segment. For dsa + and dsh entries, the size is reported as NULL + because the server does not attach to these areas in order to retrieve their size. + + + + +
+ + + By default, access to the pg_dsm_registry_allocations + view is restricted to superusers or roles granted the + pg_read_all_stats role due to the sensitive nature + of dynamic shared memory usage information. + + + <structname>pg_stats</structname> diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index e5dbbe61b81..e637f080a37 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -666,6 +666,14 @@ GRANT SELECT ON pg_shmem_allocations_numa TO pg_read_all_stats; REVOKE EXECUTE ON FUNCTION pg_get_shmem_allocations_numa() FROM PUBLIC; GRANT EXECUTE ON FUNCTION pg_get_shmem_allocations_numa() TO pg_read_all_stats; +CREATE VIEW pg_dsm_registry_allocations AS +SELECT * FROM pg_get_dsm_registry_allocations(); + +REVOKE ALL ON pg_dsm_registry_allocations FROM PUBLIC; +GRANT SELECT ON pg_dsm_registry_allocations TO pg_read_all_stats; +REVOKE EXECUTE ON FUNCTION pg_get_dsm_registry_allocations() FROM PUBLIC; +GRANT EXECUTE ON FUNCTION pg_get_dsm_registry_allocations() TO pg_read_all_stats; + CREATE VIEW pg_backend_memory_contexts AS SELECT * FROM pg_get_backend_memory_contexts(); diff --git a/src/backend/storage/ipc/dsm_registry.c b/src/backend/storage/ipc/dsm_registry.c index 828c2ff0c7f..1934e086b0a 100644 --- a/src/backend/storage/ipc/dsm_registry.c +++ b/src/backend/storage/ipc/dsm_registry.c @@ -40,10 +40,12 @@ #include "postgres.h" +#include "funcapi.h" #include "lib/dshash.h" #include "storage/dsm_registry.h" #include "storage/lwlock.h" #include "storage/shmem.h" +#include "utils/builtins.h" #include "utils/memutils.h" #define DSMR_NAME_LEN 128 @@ -435,3 +437,67 @@ GetNamedDSHash(const char *name, const dshash_parameters *params, bool *found) return ret; } + +Datum +pg_get_dsm_registry_allocations(PG_FUNCTION_ARGS) +{ + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + DSMRegistryEntry *entry; + dshash_seq_status status; + + InitMaterializedSRF(fcinfo, MAT_SRF_USE_EXPECTED_DESC); + + /* Ensure DSM registry initialized */ + init_dsm_registry(); + + /* Use non-exclusive access to avoid blocking other backends */ + dshash_seq_init(&status, dsm_registry_table, false); + + while ((entry = dshash_seq_next(&status)) != NULL) + { + /* name, type, size */ + Datum values[3]; + bool nulls[3] = {false, false, false}; + + /* 0: name */ + values[0] = CStringGetTextDatum(entry->name); + + /* 1: type */ + switch (entry->type) { + case DSMR_ENTRY_TYPE_DSM: + values[1] = CStringGetTextDatum("dsm"); + break; + case DSMR_ENTRY_TYPE_DSA: + values[1] = CStringGetTextDatum("dsa"); + break; + case DSMR_ENTRY_TYPE_DSH: + values[1] = CStringGetTextDatum("dsh"); + break; + default: + values[1] = CStringGetTextDatum("unknown"); + break; + } + + /* 2: size */ + switch (entry->type) + { + case DSMR_ENTRY_TYPE_DSM: + values[2] = Int64GetDatum(entry->data.dsm.size); + break; + + /* in case of dsa or dsh we return NULL */ + case DSMR_ENTRY_TYPE_DSA: + case DSMR_ENTRY_TYPE_DSH: + default: + nulls[2] = true; + break; + } + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, + values, nulls); + } + + dshash_seq_term(&status); + + return (Datum) 0; +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index d4650947c63..2f5df3affae 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -8559,6 +8559,12 @@ proallargtypes => '{text,int8,int8,int8}', proargmodes => '{o,o,o,o}', proargnames => '{name,off,size,allocated_size}', prosrc => 'pg_get_shmem_allocations' }, +{ oid => '6062', descr => 'dsm registry allocations', + proname => 'pg_get_dsm_registry_allocations', prorows => '50', proretset => 't', + provolatile => 'v', prorettype => 'record', proargtypes => '', + proallargtypes => '{text,text,int8}', proargmodes => '{o,o,o}', + proargnames => '{name,type,size}', + prosrc => 'pg_get_dsm_registry_allocations' }, { oid => '4099', descr => 'Is NUMA support available?', proname => 'pg_numa_available', provolatile => 's', prorettype => 'bool', diff --git a/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out b/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out index 8ded82e59d6..90f0a888a16 100644 --- a/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out +++ b/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out @@ -24,3 +24,12 @@ SELECT get_val_in_hash('test'); 1414 (1 row) +\c +SELECT name, type, size > 0 OR size ISNULL as size FROM pg_dsm_registry_allocations WHERE name like 'test_dsm_registry%'; + name | type | size +------------------------+------+------ + test_dsm_registry_dsa | dsa | t + test_dsm_registry_hash | dsh | t + test_dsm_registry_dsm | dsm | t +(3 rows) + diff --git a/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql b/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql index c2e25cddaae..a84beaec6c5 100644 --- a/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql +++ b/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql @@ -4,3 +4,5 @@ SELECT set_val_in_hash('test', '1414'); \c SELECT get_val_in_shmem(); SELECT get_val_in_hash('test'); +\c +SELECT name, type, size > 0 OR size ISNULL as size FROM pg_dsm_registry_allocations WHERE name like 'test_dsm_registry%'; diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 6cf828ca8d0..dce8c672b40 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1340,6 +1340,10 @@ pg_cursors| SELECT name, is_scrollable, creation_time FROM pg_cursor() c(name, statement, is_holdable, is_binary, is_scrollable, creation_time); +pg_dsm_registry_allocations| SELECT name, + type, + size + FROM pg_get_dsm_registry_allocations() pg_get_dsm_registry_allocations(name, type, size); pg_file_settings| SELECT sourcefile, sourceline, seqno, -- 2.49.0