Add support for basic NUMA awareness

Add basic NUMA awareness routines, using a minimal src/port/pg_numa.c
portability wrapper and an optional build dependency, enabled by
--with-libnuma configure option. For now this is Linux-only, other
platforms may be supported later.

A built-in SQL function pg_numa_available() allows checking NUMA
support, i.e. that the server was built/linked with the NUMA library.

The main function introduced is pg_numa_query_pages(), which allows
determining the NUMA node for individual memory pages. Internally the
function uses move_pages(2) syscall, as it allows batching, and is more
efficient than get_mempolicy(2).

Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Co-authored-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com

.cirrus.tasks.yml

@@ -471,6 +471,7 @@ task:
             --enable-cassert --enable-injection-points --enable-debug \
             --enable-tap-tests --enable-nls \
             --with-segsize-blocks=6 \
+            --with-libnuma \
             --with-liburing \
             \
             ${LINUX_CONFIGURE_FEATURES} \
@@ -523,6 +524,7 @@ task:
             -Dllvm=disabled \
             --pkg-config-path /usr/lib/i386-linux-gnu/pkgconfig/ \
             -DPERL=perl5.36-i386-linux-gnu \
+            -Dlibnuma=disabled \
             build-32
         EOF
 

configure

@@ -708,6 +708,9 @@ XML2_LIBS
 XML2_CFLAGS
 XML2_CONFIG
 with_libxml
+LIBNUMA_LIBS
+LIBNUMA_CFLAGS
+with_libnuma
 LIBCURL_LIBS
 LIBCURL_CFLAGS
 with_libcurl
@@ -872,6 +875,7 @@ with_liburing
 with_uuid
 with_ossp_uuid
 with_libcurl
+with_libnuma
 with_libxml
 with_libxslt
 with_system_tzdata
@@ -906,6 +910,8 @@ LIBURING_CFLAGS
 LIBURING_LIBS
 LIBCURL_CFLAGS
 LIBCURL_LIBS
+LIBNUMA_CFLAGS
+LIBNUMA_LIBS
 XML2_CONFIG
 XML2_CFLAGS
 XML2_LIBS
@@ -1588,6 +1594,7 @@ Optional Packages:
   --with-uuid=LIB         build contrib/uuid-ossp using LIB (bsd,e2fs,ossp)
   --with-ossp-uuid        obsolete spelling of --with-uuid=ossp
   --with-libcurl          build with libcurl support
+  --with-libnuma          build with libnuma support
   --with-libxml           build with XML support
   --with-libxslt          use XSLT support when building contrib/xml2
   --with-system-tzdata=DIR
@@ -1629,6 +1636,10 @@ Some influential environment variables:
               C compiler flags for LIBCURL, overriding pkg-config
   LIBCURL_LIBS
               linker flags for LIBCURL, overriding pkg-config
+  LIBNUMA_CFLAGS
+              C compiler flags for LIBNUMA, overriding pkg-config
+  LIBNUMA_LIBS
+              linker flags for LIBNUMA, overriding pkg-config
   XML2_CONFIG path to xml2-config utility
   XML2_CFLAGS C compiler flags for XML2, overriding pkg-config
   XML2_LIBS   linker flags for XML2, overriding pkg-config
@@ -9063,6 +9074,182 @@ $as_echo "$as_me: WARNING: *** OAuth support tests require --with-python to run"
 fi
 
 
+#
+# libnuma
+#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build with libnuma support" >&5
+$as_echo_n "checking whether to build with libnuma support... " >&6; }
+
+
+
+# Check whether --with-libnuma was given.
+if test "${with_libnuma+set}" = set; then :
+  withval=$with_libnuma;
+  case $withval in
+    yes)
+
+$as_echo "#define USE_LIBNUMA 1" >>confdefs.h
+
+      ;;
+    no)
+      :
+      ;;
+    *)
+      as_fn_error $? "no argument expected for --with-libnuma option" "$LINENO" 5
+      ;;
+  esac
+
+else
+  with_libnuma=no
+
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $with_libnuma" >&5
+$as_echo "$with_libnuma" >&6; }
+
+
+if test "$with_libnuma" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for numa_available in -lnuma" >&5
+$as_echo_n "checking for numa_available in -lnuma... " >&6; }
+if ${ac_cv_lib_numa_numa_available+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lnuma  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char numa_available ();
+int
+main ()
+{
+return numa_available ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_numa_numa_available=yes
+else
+  ac_cv_lib_numa_numa_available=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_numa_numa_available" >&5
+$as_echo "$ac_cv_lib_numa_numa_available" >&6; }
+if test "x$ac_cv_lib_numa_numa_available" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBNUMA 1
+_ACEOF
+
+  LIBS="-lnuma $LIBS"
+
+else
+  as_fn_error $? "library 'libnuma' is required for NUMA support" "$LINENO" 5
+fi
+
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for numa" >&5
+$as_echo_n "checking for numa... " >&6; }
+
+if test -n "$LIBNUMA_CFLAGS"; then
+    pkg_cv_LIBNUMA_CFLAGS="$LIBNUMA_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"numa\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "numa") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LIBNUMA_CFLAGS=`$PKG_CONFIG --cflags "numa" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$LIBNUMA_LIBS"; then
+    pkg_cv_LIBNUMA_LIBS="$LIBNUMA_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"numa\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "numa") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LIBNUMA_LIBS=`$PKG_CONFIG --libs "numa" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        LIBNUMA_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "numa" 2>&1`
+        else
+	        LIBNUMA_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "numa" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$LIBNUMA_PKG_ERRORS" >&5
+
+	as_fn_error $? "Package requirements (numa) were not met:
+
+$LIBNUMA_PKG_ERRORS
+
+Consider adjusting the PKG_CONFIG_PATH environment variable if you
+installed software in a non-standard prefix.
+
+Alternatively, you may set the environment variables LIBNUMA_CFLAGS
+and LIBNUMA_LIBS to avoid the need to call pkg-config.
+See the pkg-config man page for more details." "$LINENO" 5
+elif test $pkg_failed = untried; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+	{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "The pkg-config script could not be found or is too old.  Make sure it
+is in your PATH or set the PKG_CONFIG environment variable to the full
+path to pkg-config.
+
+Alternatively, you may set the environment variables LIBNUMA_CFLAGS
+and LIBNUMA_LIBS to avoid the need to call pkg-config.
+See the pkg-config man page for more details.
+
+To get pkg-config, see <http://pkg-config.freedesktop.org/>.
+See \`config.log' for more details" "$LINENO" 5; }
+else
+	LIBNUMA_CFLAGS=$pkg_cv_LIBNUMA_CFLAGS
+	LIBNUMA_LIBS=$pkg_cv_LIBNUMA_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+fi
+fi
+
 #
 # XML
 #

configure.ac

@@ -1053,6 +1053,20 @@ if test "$with_libcurl" = yes ; then
 fi
 
 
+#
+# libnuma
+#
+AC_MSG_CHECKING([whether to build with libnuma support])
+PGAC_ARG_BOOL(with, libnuma, no, [build with libnuma support],
+              [AC_DEFINE([USE_LIBNUMA], 1, [Define to build with NUMA support. (--with-libnuma)])])
+AC_MSG_RESULT([$with_libnuma])
+AC_SUBST(with_libnuma)
+
+if test "$with_libnuma" = yes ; then
+  AC_CHECK_LIB(numa,    numa_available, [], [AC_MSG_ERROR([library 'libnuma' is required for NUMA support])])
+  PKG_CHECK_MODULES(LIBNUMA, numa)
+fi
+
 #
 # XML
 #

doc/src/sgml/func.sgml

@@ -25143,6 +25143,19 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n);
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_numa_available</primary>
+        </indexterm>
+        <function>pg_numa_available</function> ()
+        <returnvalue>boolean</returnvalue>
+       </para>
+       <para>
+        Returns true if the server has been compiled with <acronym>NUMA</acronym> support.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>

doc/src/sgml/installation.sgml

@@ -1156,6 +1156,17 @@ build-postgresql:
        </listitem>
       </varlistentry>
 
+      <varlistentry id="configure-option-with-libnuma">
+       <term><option>--with-libnuma</option></term>
+       <listitem>
+        <para>
+         Build with libnuma support for basic NUMA support.
+         Only supported on platforms for which the <productname>libnuma</productname>
+         library is implemented.
+        </para>
+       </listitem>
+      </varlistentry>
+
       <varlistentry id="configure-option-with-liburing">
        <term><option>--with-liburing</option></term>
        <listitem>
@@ -2645,6 +2656,17 @@ ninja install
       </listitem>
      </varlistentry>
 
+     <varlistentry id="configure-with-libnuma-meson">
+      <term><option>-Dlibnuma={ auto | enabled | disabled }</option></term>
+      <listitem>
+       <para>
+        Build with libnuma support for basic NUMA support.
+        Only supported on platforms for which the <productname>libnuma</productname>
+        library is implemented. The default for this option is auto.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="configure-with-libxml-meson">
       <term><option>-Dlibxml={ auto | enabled | disabled }</option></term>
       <listitem>

meson.build

@@ -943,6 +943,27 @@ else
 endif
 
 
+###############################################################
+# Library: libnuma
+###############################################################
+
+libnumaopt = get_option('libnuma')
+if not libnumaopt.disabled()
+  # via pkg-config
+  libnuma = dependency('numa', required: false)
+  if not libnuma.found()
+    libnuma = cc.find_library('numa', required: libnumaopt)
+  endif
+  if not cc.has_header('numa.h', dependencies: libnuma, required: libnumaopt)
+    libnuma = not_found_dep
+  endif
+  if libnuma.found()
+    cdata.set('USE_LIBNUMA', 1)
+  endif
+else
+  libnuma = not_found_dep
+endif
+
 
 ###############################################################
 # Library: liburing
@@ -3279,6 +3300,7 @@ backend_both_deps += [
   icu_i18n,
   ldap,
   libintl,
+  libnuma,
   liburing,
   libxml,
   lz4,
@@ -3935,6 +3957,7 @@ if meson.version().version_compare('>=0.57')
       'icu': icu,
       'ldap': ldap,
       'libcurl': libcurl,
+      'libnuma': libnuma,
       'liburing': liburing,
       'libxml': libxml,
       'libxslt': libxslt,

meson_options.txt

@@ -106,6 +106,9 @@ option('libcurl', type : 'feature', value: 'auto',
 option('libedit_preferred', type: 'boolean', value: false,
   description: 'Prefer BSD Libedit over GNU Readline')
 
+option('libnuma', type: 'feature', value: 'auto',
+  description: 'NUMA support')
+
 option('liburing', type : 'feature', value: 'auto',
   description: 'io_uring support, for asynchronous I/O')
 

src/Makefile.global.in

@@ -196,6 +196,7 @@ with_gssapi	= @with_gssapi@
 with_krb_srvnam	= @with_krb_srvnam@
 with_ldap	= @with_ldap@
 with_libcurl	= @with_libcurl@
+with_libnuma	= @with_libnuma@
 with_liburing	= @with_liburing@
 with_libxml	= @with_libxml@
 with_libxslt	= @with_libxslt@
@@ -223,6 +224,9 @@ krb_srvtab = @krb_srvtab@
 ICU_CFLAGS		= @ICU_CFLAGS@
 ICU_LIBS		= @ICU_LIBS@
 
+LIBNUMA_CFLAGS		= @LIBNUMA_CFLAGS@
+LIBNUMA_LIBS		= @LIBNUMA_LIBS@
+
 LIBURING_CFLAGS		= @LIBURING_CFLAGS@
 LIBURING_LIBS		= @LIBURING_LIBS@
 
@@ -250,7 +254,7 @@ CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
 PG_SYSROOT = @PG_SYSROOT@
 
-override CPPFLAGS := $(ICU_CFLAGS) $(LIBURING_CFLAGS) $(CPPFLAGS)
+override CPPFLAGS := $(ICU_CFLAGS) $(LIBNUMA_CFLAGS) $(LIBURING_CFLAGS) $(CPPFLAGS)
 
 ifdef PGXS
 override CPPFLAGS := -I$(includedir_server) -I$(includedir_internal) $(CPPFLAGS)

src/backend/utils/misc/guc_tables.c

@@ -566,7 +566,7 @@ static int	ssl_renegotiation_limit;
  */
 int			huge_pages = HUGE_PAGES_TRY;
 int			huge_page_size;
-static int	huge_pages_status = HUGE_PAGES_UNKNOWN;
+int			huge_pages_status = HUGE_PAGES_UNKNOWN;
 
 /*
  * These variables are all dummies that don't do anything, except in some

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202504071
+#define CATALOG_VERSION_NO	202504072
 
 #endif

src/include/catalog/pg_proc.dat

@@ -8542,6 +8542,10 @@
   proargnames => '{name,off,size,allocated_size}',
   prosrc => 'pg_get_shmem_allocations' },
 
+{ oid => '4099', descr => 'Is NUMA support available?',
+  proname => 'pg_numa_available', provolatile => 's', prorettype => 'bool',
+  proargtypes => '', prosrc => 'pg_numa_available' },
+
 # memory context of local backend
 { oid => '2282',
   descr => 'information about all memory contexts of local backend',

src/include/pg_config.h.in

@@ -689,6 +689,9 @@
 /* Define to 1 to build with libcurl support. (--with-libcurl) */
 #undef USE_LIBCURL
 
+/* Define to 1 to build with NUMA support. (--with-libnuma) */
+#undef USE_LIBNUMA
+
 /* Define to build with io_uring support. (--with-liburing) */
 #undef USE_LIBURING
 

src/include/port/pg_numa.h

@@ -0,0 +1,40 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_numa.h
+ *	  Basic NUMA portability routines
+ *
+ *
+ * Copyright (c) 2025, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * 	src/include/port/pg_numa.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_NUMA_H
+#define PG_NUMA_H
+
+#include "fmgr.h"
+
+extern PGDLLIMPORT int pg_numa_init(void);
+extern PGDLLIMPORT int pg_numa_query_pages(int pid, unsigned long count, void **pages, int *status);
+extern PGDLLIMPORT int pg_numa_get_max_node(void);
+extern PGDLLIMPORT Size pg_numa_get_pagesize(void);
+
+#ifdef USE_LIBNUMA
+
+/*
+ * This is required on Linux, before pg_numa_query_pages() as we
+ * need to page-fault before move_pages(2) syscall returns valid results.
+ */
+#define pg_numa_touch_mem_if_required(ro_volatile_var, ptr) \
+	ro_volatile_var = *(volatile uint64 *) ptr
+
+#else
+
+#define pg_numa_touch_mem_if_required(ro_volatile_var, ptr) \
+	do {} while(0)
+
+#endif
+
+#endif							/* PG_NUMA_H */

src/include/storage/pg_shmem.h

@@ -45,6 +45,7 @@ typedef struct PGShmemHeader	/* standard header for all Postgres shmem */
 extern PGDLLIMPORT int shared_memory_type;
 extern PGDLLIMPORT int huge_pages;
 extern PGDLLIMPORT int huge_page_size;
+extern PGDLLIMPORT int huge_pages_status;
 
 /* Possible values for huge_pages and huge_pages_status */
 typedef enum

src/makefiles/meson.build

@@ -200,6 +200,8 @@ pgxs_empty = [
 
   'ICU_LIBS',
 
+  'LIBNUMA_CFLAGS', 'LIBNUMA_LIBS',
+
   'LIBURING_CFLAGS', 'LIBURING_LIBS',
 ]
 
@@ -232,6 +234,7 @@ pgxs_deps = {
   'icu': icu,
   'ldap': ldap,
   'libcurl': libcurl,
+  'libnuma': libnuma,
   'liburing': liburing,
   'libxml': libxml,
   'libxslt': libxslt,

src/port/Makefile

@@ -45,6 +45,7 @@ OBJS = \
 	path.o \
 	pg_bitutils.o \
 	pg_localeconv_r.o \
+	pg_numa.o \
 	pg_popcount_aarch64.o \
 	pg_popcount_avx512.o \
 	pg_strong_random.o \

src/port/meson.build

@@ -8,6 +8,7 @@ pgport_sources = [
   'path.c',
   'pg_bitutils.c',
   'pg_localeconv_r.c',
+  'pg_numa.c',
   'pg_popcount_aarch64.c',
   'pg_popcount_avx512.c',
   'pg_strong_random.c',

src/port/pg_numa.c

@@ -0,0 +1,120 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_numa.c
+ * 		Basic NUMA portability routines
+ *
+ *
+ * Copyright (c) 2025, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/port/pg_numa.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include <unistd.h>
+
+#ifdef WIN32
+#include <windows.h>
+#endif
+
+#include "fmgr.h"
+#include "miscadmin.h"
+#include "port/pg_numa.h"
+#include "storage/pg_shmem.h"
+
+/*
+ * At this point we provide support only for Linux thanks to libnuma, but in
+ * future support for other platforms e.g. Win32 or FreeBSD might be possible
+ * too. For Win32 NUMA APIs see
+ * https://learn.microsoft.com/en-us/windows/win32/procthread/numa-support
+ */
+#ifdef USE_LIBNUMA
+
+#include <numa.h>
+#include <numaif.h>
+
+Datum		pg_numa_available(PG_FUNCTION_ARGS);
+
+/* libnuma requires initialization as per numa(3) on Linux */
+int
+pg_numa_init(void)
+{
+	int			r = numa_available();
+
+	return r;
+}
+
+/*
+ * We use move_pages(2) syscall here - instead of get_mempolicy(2) - as the
+ * first one allows us to batch and query about many memory pages in one single
+ * giant system call that is way faster.
+ */
+int
+pg_numa_query_pages(int pid, unsigned long count, void **pages, int *status)
+{
+	return numa_move_pages(pid, count, pages, NULL, status, 0);
+}
+
+int
+pg_numa_get_max_node(void)
+{
+	return numa_max_node();
+}
+
+#else
+
+Datum		pg_numa_available(PG_FUNCTION_ARGS);
+
+/* Empty wrappers */
+int
+pg_numa_init(void)
+{
+	/* We state that NUMA is not available */
+	return -1;
+}
+
+int
+pg_numa_query_pages(int pid, unsigned long count, void **pages, int *status)
+{
+	return 0;
+}
+
+int
+pg_numa_get_max_node(void)
+{
+	return 0;
+}
+
+#endif
+
+Datum
+pg_numa_available(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(pg_numa_init() != -1);
+}
+
+/* This should be used only after the server is started */
+Size
+pg_numa_get_pagesize(void)
+{
+	Size		os_page_size;
+#ifdef WIN32
+	SYSTEM_INFO sysinfo;
+
+	GetSystemInfo(&sysinfo);
+	os_page_size = sysinfo.dwPageSize;
+#else
+	os_page_size = sysconf(_SC_PAGESIZE);
+#endif
+
+	Assert(IsUnderPostmaster);
+	Assert(huge_pages_status != HUGE_PAGES_UNKNOWN);
+
+	if (huge_pages_status == HUGE_PAGES_ON)
+		GetHugePageSize(&os_page_size, NULL);
+
+	return os_page_size;
+}