On Tue, Apr 1, 2025 at 10:17 PM Tomas Vondra <to...@vondra.me> wrote:
>
> Hi,
>
> I've spent a bit of time reviewing this. In general I haven't found
> anything I'd call a bug, but here's a couple comments for v18 ... Most
> of this is in separate "review" commits, with a couple exceptions.
Hi, thank you very much for help on this, yes I did not anticipate
this patch to organically grow like that...
I've squashed those review findings into v20 and provided answers for
the "review:".
> 1) Please update the commit messages, with proper formatting, etc. I
> tried to do that in the attached v19, but please go through that, add
> relevant details, update list of reviewers, etc. The subject should not
> be overly long, etc.
Fixed by you.
> 2) I don't think we need "libnuma for NUMA awareness" in configure, I'd
> use just "libnuma support" similar to other libraries.
Fixed by you.
> 3) I don't think we need pg_numa.h to have this:
>
> extern PGDLLIMPORT Datum pg_numa_available(PG_FUNCTION_ARGS);
>
> AFAICS we don't have any SQL functions exposed as PGDLLIMPORT, so why
> would it be necessary here? It's enough to have a prototype in .c file.
Right, probably the result of ENOTENOUGHCOFFEE and copy/paste.
> 4) Improved .sgml to have acronym/productname in a couple places.
Great.
> 5) I don't think the comment for pg_buffercache_init_entries() is very
> useful. That it's helper for pg_buffercache_pages() tells me nothing
> about how to use it, what the arguments are, etc.
I've added an explanation (in 0003 though), so that this is covered.
I've always assumed that 'static' functions don't need that much of
that(?)
> 6) IMHO pg_buffercache_numa_prepare_ptrs() would deserve a better
> comment too. I mean, there's no info about what the arguments are, which
> arguments are input or output, etc. And it only discussed one option
> (block page < memory page), but what happens in the other case? The
> formulas with blk2page/blk2pageoff are not quite clear to me (I'm not
> saying it's wrong).
>
> However, it seems rather suspicious that pages_per_blk is calculated as
> float, and pg_buffercache_numa_prepare_ptrs() then does this:
>
> for (size_t j = 0; j < pages_per_blk; j++)
> { ... }
>
> I mean, isn't this vulnerable to rounding errors, which might trigger
> some weird behavior? If not, it'd be good to add a comment why this is
> fine, it confuses me a lot. I personally would probably prefer doing
> just integer arithmetic here.
Please bear with me: If you set client_min_messages to debug1 and then
pg_buffercache_numa will dump:
a) without HP, DEBUG: NUMA: os_page_count=32768 os_page_size=4096
pages_per_blk=2.00
b) with HP (2M) DEBUG: NUMA: os_page_count=64 os_page_size=2097152
pages_per_blk=0.003906
so we need to be agile to support two cases as you mention (BLCKSZ >
PAGESIZE and BLCKSZ < PAGESIZE). BLCKSZ are 2..32kB and pagesize are
4kB..1GB, thus we can get in that float the following sample values:
BLCKSZ pagesize
2kB 4kB = 0.5
2kB 2048kb = .0009765625
2kB 1024*1024kb # 1GB = .0000019073486328125 # worst-case?
8kB 4kB = 2
8kB 2048kb = .003906250 # example from above (x86_64, 2M HP)
8kB 1024*1024kb # 1GB = .00000762939453
32kB 4kB = 8
32kB 2048kb = .0156250
32kB 1024*1024kb # 1GB = .000030517578125
So that loop:
for (size_t j = 0; j < pages_per_blk; j++)
is quite generic and launches in both cases. I've somehow failed to
somehow come up with integer-based math and generic code for this
(without special cases which seem to be no-go here?). So, that loop
then will:
a) launch many times to support BLCKSZ > pagesize, that is when single
DB block spans multiple memory pages
b) launch once when BLCKSZ < pagesize (because 0.003906250 > 0 in the
example above)
Loop touches && stores addresses into os_page_ptrs[] as input to this
one big move_pages(2) query. So we basically ask for all memory pages
for NBuffers. Once we get our NUMA information we then use blk2page =
up_to_NBuffers * pages_per_blk to resolve memory pointers back to
Buffers, if anywhere it could be a problem here.
So let's say we have s_b=4TB (it wont work for sure for other reasons,
let's assume we have it), let's also assume we have no huge
pages(pagesize=4kB) and BLCKSZ=8kB (default) => NBuffers=1073741824
which multiplied by 2 = INT_MAX (integer overflow bug), so I think
that int is not big enough there in pg_buffercache_numa_pages() (it
should be "size_t blk2page" there as in
pg_buffercache_numa_prepare_ptrs(), so I've changed it in v20)
Another angle is s_b=4TB RAM with 2MB HP, BLKSZ=8kB =>
NBuffers=2097152 * 0.003906250 = 8192.0 .
OPEN_QUESTION: I'm not sure all of this is safe and I'm seeking help, but with
float f = 2097152 * 0.003906250;
under clang -Weverything I got "implicit conversion increases
floating-point precision: 'float' to 'double'", so either it is:
- we somehow rewrite all of the core arithmetics here to integer?
- or simply go with doubles just to be sure? I went with doubles in
v20, comments explaining are not there yet.
> 7) This para in the docs seems self-contradictory:
>
> <para>
> The <function>pg_buffercache_numa_pages()</function> provides the same
> information
> as <function>pg_buffercache_pages()</function> but is slower because
> it also
> provides the <acronym>NUMA</acronym> node ID per shared buffer entry.
> The <structname>pg_buffercache_numa</structname> view wraps the
> function for
> convenient use.
> </para>
>
> I mean, "provides the same information, but is slower because it
> provides different information" is strange. I understand the point, but
> maybe rephrase somehow?
Oh my... yes, now it looks way better.
> 8) Why is pg_numa_available() marked as volatile? Should not change in a
> running cluster, no?
No it shouldn't, good find, made it 's'table.
> 9) I noticed the new SGML docs have IDs with mixed "-" and "_". Maybe
> let's not do that.
>
> <sect2 id="pgbuffercache-pg-buffercache_numa">
Fixed.
> 10) I think it'd be good to mention/explain why move_pages is used
> instead of get_mempolicy - more efficient with batching, etc. This would
> be useful both in the commit message and before the move_pages call
Ok, added in 0001.
> (and in general to explain why pg_buffercache_numa_prepare_ptrs prepares the
> pointers like this etc.).
Added reference to that earlier new comment here too in 0003.
> 11) This could use UINT64_FORMAT, instead of a cast:
>
> elog(DEBUG1, "NUMA: os_page_count=%lu os_page_size=%zu
> pages_per_blk=%.2f",
> (unsigned long) os_page_count, os_page_size, pages_per_blk);
Done.
12) You have also raised "why not pg_shm_allocations_numa" instead of
"pg_shm_numa_allocations"
OPEN_QUESTION: To be honest, I'm not attached to any of those two (or
naming things in general), I can change if you want.
13) In the patch: "review: What if we get multiple pages per buffer
(the default). Could we get multiple nodes per buffer?"
OPEN_QUESTION: Today no, but if we would modify pg_buffercache_numa to
output multiple rows per single buffer (with "page_no") then we could
get this:
buffer1:..:page0:numanodeID1
buffer1:..:page1:numanodeID2
buffer2:..:page0:numanodeID1
Should we add such functionality?
-J.
From fe5cc5eaf57b1ddf81d8852da5442fef27960027 Mon Sep 17 00:00:00 2001
From: Jakub Wartak <jakub.wartak@enterprisedb.com>
Date: Wed, 2 Apr 2025 12:29:22 +0200
Subject: [PATCH v20 1/4] Add support for basic NUMA awareness
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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 NUMA library.
The libnuma library is not available on 32-bit builds (there's no shared
object for i386), so we disable it in that case. The i386 is very memory
limited anyway, even with PAE, so NUMA is mostly irrelevant.
On Linux we use move_pages(2) syscall for speed instead of
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 | 2 +
configure | 187 ++++++++++++++++++++++++++++
configure.ac | 14 +++
doc/src/sgml/func.sgml | 13 ++
doc/src/sgml/installation.sgml | 21 ++++
meson.build | 23 ++++
meson_options.txt | 3 +
src/Makefile.global.in | 6 +-
src/backend/utils/misc/guc_tables.c | 2 +-
src/include/catalog/pg_proc.dat | 4 +
src/include/pg_config.h.in | 3 +
src/include/port/pg_numa.h | 40 ++++++
src/include/storage/pg_shmem.h | 1 +
src/makefiles/meson.build | 3 +
src/port/Makefile | 1 +
src/port/meson.build | 1 +
src/port/pg_numa.c | 120 ++++++++++++++++++
17 files changed, 442 insertions(+), 2 deletions(-)
create mode 100644 src/include/port/pg_numa.h
create mode 100644 src/port/pg_numa.c
diff --git a/.cirrus.tasks.yml b/.cirrus.tasks.yml
index 86a1fa9bbdb..6f4f5c674a1 100644
--- a/.cirrus.tasks.yml
+++ b/.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
diff --git a/configure b/configure
index 3d0e701c745..8308200dce7 100755
--- a/configure
+++ b/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 for NUMA awareness
--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 $? "library 'libnuma' is required for NUMA awareness" "$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
+$as_echo "yes" >&6; }
+
+fi
+fi
+
#
# XML
#
diff --git a/configure.ac b/configure.ac
index 47a287926bc..ab4a0dc2be7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1053,6 +1053,20 @@ if test "$with_libcurl" = yes ; then
fi
+#
+# libnuma
+#
+AC_MSG_CHECKING([whether to build with libnuma support])
+PGAC_ARG_BOOL(with, libnuma, no, [build with libnuma for NUMA awareness],
+ [AC_DEFINE([USE_LIBNUMA], 1, [Define to build with NUMA awareness 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 awareness])])
+ PKG_CHECK_MODULES(LIBNUMA, numa)
+fi
+
#
# XML
#
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 2488e9ba998..4bb60e9e080 100644
--- a/doc/src/sgml/func.sgml
+++ b/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>
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index cc28f041330..5f0486bb335 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -1156,6 +1156,16 @@ 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 libnuma library is implemented.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="configure-option-with-liburing">
<term><option>--with-liburing</option></term>
<listitem>
@@ -2645,6 +2655,17 @@ 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 libnuma 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>
diff --git a/meson.build b/meson.build
index ba7916d1493..7cd524307b3 100644
--- a/meson.build
+++ b/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: libnumaopt)
+ 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
@@ -3240,6 +3261,7 @@ backend_both_deps += [
icu_i18n,
ldap,
libintl,
+ libnuma,
liburing,
libxml,
lz4,
@@ -3896,6 +3918,7 @@ if meson.version().version_compare('>=0.57')
'icu': icu,
'ldap': ldap,
'libcurl': libcurl,
+ 'libnuma': libnuma,
'liburing': liburing,
'libxml': libxml,
'libxslt': libxslt,
diff --git a/meson_options.txt b/meson_options.txt
index dd7126da3a7..8675e1b5d87 100644
--- a/meson_options.txt
+++ b/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 awareness support')
+
option('liburing', type : 'feature', value: 'auto',
description: 'io_uring support, for asynchronous I/O')
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index cce29a37ac5..8b61d1ed492 100644
--- a/src/Makefile.global.in
+++ b/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)
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 4eaeca89f2c..ea8d796e7c4 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6b57b7e18d9..e6730ac703c 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -8518,6 +8518,10 @@
proargnames => '{name,off,size,allocated_size}',
prosrc => 'pg_get_shmem_allocations' },
+{ oid => '9685', descr => 'Is NUMA compilation 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',
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 2ac61575883..b7144cbf32f 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -676,6 +676,9 @@
/* Define to 1 to build with libcurl support. (--with-libcurl) */
#undef USE_LIBCURL
+/* Define to 1 to build with NUMA awareness support. (--with-libnuma) */
+#undef USE_LIBNUMA
+
/* Define to build with io_uring support. (--with-liburing) */
#undef USE_LIBURING
diff --git a/src/include/port/pg_numa.h b/src/include/port/pg_numa.h
new file mode 100644
index 00000000000..314cff94dbc
--- /dev/null
+++ b/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 = *(uint64 *)ptr
+
+#else
+
+#define pg_numa_touch_mem_if_required(ro_volatile_var, ptr) \
+ do {} while(0)
+
+#endif
+
+#endif /* PG_NUMA_H */
diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h
index b99ebc9e86f..5f7d4b83a60 100644
--- a/src/include/storage/pg_shmem.h
+++ b/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
diff --git a/src/makefiles/meson.build b/src/makefiles/meson.build
index 46d8da070e8..55da678ec27 100644
--- a/src/makefiles/meson.build
+++ b/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,
diff --git a/src/port/Makefile b/src/port/Makefile
index f11896440d5..4274949dfa4 100644
--- a/src/port/Makefile
+++ b/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 \
diff --git a/src/port/meson.build b/src/port/meson.build
index cf7f07644b9..3b26c68fda7 100644
--- a/src/port/meson.build
+++ b/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',
diff --git a/src/port/pg_numa.c b/src/port/pg_numa.c
new file mode 100644
index 00000000000..5e2523cf798
--- /dev/null
+++ b/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;
+}
--
2.39.5
From 752664b8e05982f054500203eba7c49dd52fdb46 Mon Sep 17 00:00:00 2001
From: Jakub Wartak <jakub.wartak@enterprisedb.com>
Date: Fri, 21 Feb 2025 14:20:18 +0100
Subject: [PATCH v20 4/4] Add new pg_shmem_numa_allocations view
Introduce new pg_shmem_numa_alloctions view that allows viewing the shared memory split layout across
NUMA nodes.
Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com
---
doc/src/sgml/system-views.sgml | 79 ++++++++++++++
src/backend/catalog/system_views.sql | 8 ++
src/backend/storage/ipc/shmem.c | 131 +++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 ++
src/test/regress/expected/numa.out | 12 +++
src/test/regress/expected/numa_1.out | 3 +
src/test/regress/expected/privileges.out | 16 ++-
src/test/regress/expected/rules.out | 4 +
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/numa.sql | 9 ++
src/test/regress/sql/privileges.sql | 6 +-
11 files changed, 273 insertions(+), 5 deletions(-)
create mode 100644 src/test/regress/expected/numa.out
create mode 100644 src/test/regress/expected/numa_1.out
create mode 100644 src/test/regress/sql/numa.sql
diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml
index e9a59af8c34..c1d63ffc3b4 100644
--- a/doc/src/sgml/system-views.sgml
+++ b/doc/src/sgml/system-views.sgml
@@ -181,6 +181,11 @@
<entry>shared memory allocations</entry>
</row>
+ <row>
+ <entry><link linkend="view-pg-shmem-numa-allocations"><structname>pg_shmem_numa_allocations</structname></link></entry>
+ <entry>NUMA node mappings for shared memory allocations</entry>
+ </row>
+
<row>
<entry><link linkend="view-pg-stats"><structname>pg_stats</structname></link></entry>
<entry>planner statistics</entry>
@@ -4040,6 +4045,80 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
</para>
</sect1>
+ <sect1 id="view-pg-shmem-numa-allocations">
+ <title><structname>pg_shmem_numa_allocations</structname></title>
+
+ <indexterm zone="view-pg-shmem-numa-allocations">
+ <primary>pg_shmem_numa_allocations</primary>
+ </indexterm>
+
+ <para>
+ The <structname>pg_shmem_numa_allocations</structname> shows how shared
+ memory allocations in the server's main shared memory segment are distributed
+ across NUMA nodes. This includes both memory allocated by
+ <productname>PostgreSQL</productname> itself and memory allocated
+ by extensions using the mechanisms detailed in
+ <xref linkend="xfunc-shared-addin" />.
+ </para>
+
+ <para>
+ Note that this view does not include memory allocated using the dynamic
+ shared memory infrastructure.
+ </para>
+
+ <table>
+ <title><structname>pg_shmem_numa_allocations</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>name</structfield> <type>text</type>
+ </para>
+ <para>
+ The name of the shared memory allocation.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>node_id</structfield> <type>int4</type>
+ </para>
+ <para>
+ ID of <acronym>NUMA</acronym> node
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>size</structfield> <type>int4</type>
+ </para>
+ <para>
+ Size of the allocation on this particular NUMA memory node in bytes
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
+ <para>
+ By default, the <structname>pg_shmem_numa_allocations</structname> view can be
+ read only by superusers or roles with privileges of the
+ <literal>pg_read_all_stats</literal> role.
+ </para>
+ </sect1>
+
<sect1 id="view-pg-stats">
<title><structname>pg_stats</structname></title>
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 64a7240aa77..eef7a7f9788 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -658,6 +658,14 @@ GRANT SELECT ON pg_shmem_allocations TO pg_read_all_stats;
REVOKE EXECUTE ON FUNCTION pg_get_shmem_allocations() FROM PUBLIC;
GRANT EXECUTE ON FUNCTION pg_get_shmem_allocations() TO pg_read_all_stats;
+CREATE VIEW pg_shmem_numa_allocations AS
+ SELECT * FROM pg_get_shmem_numa_allocations();
+
+REVOKE ALL ON pg_shmem_numa_allocations FROM PUBLIC;
+GRANT SELECT ON pg_shmem_numa_allocations TO pg_read_all_stats;
+REVOKE EXECUTE ON FUNCTION pg_get_shmem_numa_allocations() FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pg_get_shmem_numa_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/shmem.c b/src/backend/storage/ipc/shmem.c
index 895a43fb39e..e83f066171a 100644
--- a/src/backend/storage/ipc/shmem.c
+++ b/src/backend/storage/ipc/shmem.c
@@ -68,6 +68,7 @@
#include "fmgr.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "port/pg_numa.h"
#include "storage/lwlock.h"
#include "storage/pg_shmem.h"
#include "storage/shmem.h"
@@ -89,6 +90,8 @@ slock_t *ShmemLock; /* spinlock for shared memory and LWLock
static HTAB *ShmemIndex = NULL; /* primary index hashtable for shmem */
+/* To get reliable results for NUMA inquiry we need to "touch pages" once */
+static bool firstNumaTouch = true;
/*
* InitShmemAccess() --- set up basic pointers to shared memory.
@@ -568,3 +571,131 @@ pg_get_shmem_allocations(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/* SQL SRF showing NUMA memory nodes for allocated shared memory */
+Datum
+pg_get_shmem_numa_allocations(PG_FUNCTION_ARGS)
+{
+#define PG_GET_SHMEM_NUMA_SIZES_COLS 3
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS hstat;
+ ShmemIndexEnt *ent;
+ Datum values[PG_GET_SHMEM_NUMA_SIZES_COLS];
+ bool nulls[PG_GET_SHMEM_NUMA_SIZES_COLS];
+ Size os_page_size;
+ void **page_ptrs;
+ int *pages_status;
+ uint64 shm_total_page_count,
+ shm_ent_page_count,
+ max_nodes;
+ Size *nodes;
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (pg_numa_init() == -1)
+ {
+ elog(ERROR, "libnuma initialization failed or NUMA is not supported on this platform");
+ return (Datum) 0;
+ }
+ max_nodes = pg_numa_get_max_node();
+ nodes = palloc(sizeof(Size) * (max_nodes + 1));
+
+ /*
+ * Different database block sizes (4kB, 8kB, ..., 32kB) can be used, while
+ * the OS may have different memory page sizes.
+ *
+ * To correctly map between them, we need to: 1. Determine the OS memory
+ * page size 2. Calculate how many OS pages are used by all buffer blocks
+ * 3. Calculate how many OS pages are contained within each database
+ * block.
+ *
+ * This information is needed before calling move_pages() for NUMA memory
+ * node inquiry.
+ */
+ os_page_size = pg_numa_get_pagesize();
+
+ /*
+ * Allocate memory for page pointers and status based on total shared
+ * memory size. This simplified approach allocates enough space for all
+ * pages in shared memory rather than calculating the exact requirements
+ * for each segment.
+ */
+ shm_total_page_count = ShmemSegHdr->totalsize / os_page_size;
+ page_ptrs = palloc0(sizeof(void *) * shm_total_page_count);
+ pages_status = palloc(sizeof(int) * shm_total_page_count);
+
+ if (firstNumaTouch)
+ elog(DEBUG1, "NUMA: page-faulting shared memory segments for proper NUMA readouts");
+
+ LWLockAcquire(ShmemIndexLock, LW_SHARED);
+
+ hash_seq_init(&hstat, ShmemIndex);
+
+ /* output all allocated entries */
+ memset(nulls, 0, sizeof(nulls));
+ while ((ent = (ShmemIndexEnt *) hash_seq_search(&hstat)) != NULL)
+ {
+ int i;
+
+ shm_ent_page_count = ent->allocated_size / os_page_size;
+ /* It is always at least 1 page */
+ shm_ent_page_count = shm_ent_page_count == 0 ? 1 : shm_ent_page_count;
+
+ /*
+ * If we get ever 0xff back from kernel inquiry, then we probably have
+ * bug in our buffers to OS page mapping code here.
+ */
+ memset(pages_status, 0xff, sizeof(int) * shm_ent_page_count);
+
+ for (i = 0; i < shm_ent_page_count; i++)
+ {
+ /*
+ * In order to get reliable results we also need to touch memory
+ * pages, so that inquiry about NUMA memory node doesn't return -2
+ * (which indicates unmapped/unallocated pages).
+ */
+ volatile uint64 touch pg_attribute_unused();
+
+ page_ptrs[i] = (char *) ent->location + (i * os_page_size);
+ if (firstNumaTouch)
+ pg_numa_touch_mem_if_required(touch, page_ptrs[i]);
+
+ CHECK_FOR_INTERRUPTS();
+ }
+
+ if (pg_numa_query_pages(0, shm_ent_page_count, page_ptrs, pages_status) == -1)
+ elog(ERROR, "failed NUMA pages inquiry status: %m");
+
+ memset(nodes, 0, sizeof(Size) * (max_nodes + 1));
+ /* Count number of NUMA nodes used for this shared memory entry */
+ for (i = 0; i < shm_ent_page_count; i++)
+ {
+ int s = pages_status[i];
+
+ /* Ensure we are adding only valid index to the array */
+ if (s >= 0 && s <= max_nodes)
+ nodes[s]++;
+ }
+
+ for (i = 0; i <= max_nodes; i++)
+ {
+ values[0] = CStringGetTextDatum(ent->key);
+ values[1] = i;
+ values[2] = Int64GetDatum(nodes[i] * os_page_size);
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
+ values, nulls);
+ }
+ }
+
+ /*
+ * We are ignoring the following memory regions (as compared to
+ * pg_get_shmem_allocations()): 1. output shared memory allocated but not
+ * counted via the shmem index 2. output as-of-yet unused shared memory.
+ */
+
+ LWLockRelease(ShmemIndexLock);
+ firstNumaTouch = false;
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6730ac703c..966ae7994f4 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -8522,6 +8522,14 @@
proname => 'pg_numa_available', provolatile => 's', prorettype => 'bool',
proargtypes => '', prosrc => 'pg_numa_available' },
+# shared memory usage with NUMA info
+{ oid => '9686', descr => 'NUMA mappings for the main shared memory segment',
+ proname => 'pg_get_shmem_numa_allocations', prorows => '50', proretset => 't',
+ provolatile => 'v', prorettype => 'record', proargtypes => '',
+ proallargtypes => '{text,int4,int8}', proargmodes => '{o,o,o}',
+ proargnames => '{name,node_id,size}',
+ prosrc => 'pg_get_shmem_numa_allocations' },
+
# memory context of local backend
{ oid => '2282',
descr => 'information about all memory contexts of local backend',
diff --git a/src/test/regress/expected/numa.out b/src/test/regress/expected/numa.out
new file mode 100644
index 00000000000..fb882c5b771
--- /dev/null
+++ b/src/test/regress/expected/numa.out
@@ -0,0 +1,12 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
+\endif
+-- switch to superuser
+\c -
+SELECT COUNT(*) >= 0 AS ok FROM pg_shmem_numa_allocations;
+ ok
+----
+ t
+(1 row)
+
diff --git a/src/test/regress/expected/numa_1.out b/src/test/regress/expected/numa_1.out
new file mode 100644
index 00000000000..6dd6824b4e4
--- /dev/null
+++ b/src/test/regress/expected/numa_1.out
@@ -0,0 +1,3 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index 5588d83e1bf..f66cf1bbfbd 100644
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -3127,8 +3127,8 @@ REVOKE MAINTAIN ON lock_table FROM regress_locktable_user;
-- clean up
DROP TABLE lock_table;
DROP USER regress_locktable_user;
--- test to check privileges of system views pg_shmem_allocations and
--- pg_backend_memory_contexts.
+-- test to check privileges of system views pg_shmem_allocations,
+-- pg_shmem_numa_allocations and pg_backend_memory_contexts.
-- switch to superuser
\c -
CREATE ROLE regress_readallstats;
@@ -3150,6 +3150,12 @@ SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT
f
(1 row)
+SELECT has_table_privilege('regress_readallstats','pg_shmem_numa_allocations','SELECT'); -- no
+ has_table_privilege
+---------------------
+ f
+(1 row)
+
GRANT pg_read_all_stats TO regress_readallstats;
SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- yes
has_table_privilege
@@ -3169,6 +3175,12 @@ SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT
t
(1 row)
+SELECT has_table_privilege('regress_readallstats','pg_shmem_numa_allocations','SELECT'); -- yes
+ has_table_privilege
+---------------------
+ t
+(1 row)
+
-- run query to ensure that functions within views can be executed
SET ROLE regress_readallstats;
SELECT COUNT(*) >= 0 AS ok FROM pg_aios;
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index d9533deb04e..6c5da81a2b2 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1756,6 +1756,10 @@ pg_shmem_allocations| SELECT name,
size,
allocated_size
FROM pg_get_shmem_allocations() pg_get_shmem_allocations(name, off, size, allocated_size);
+pg_shmem_numa_allocations| SELECT name,
+ node_id,
+ size
+ FROM pg_get_shmem_numa_allocations() pg_get_shmem_numa_allocations(name, node_id, size);
pg_stat_activity| SELECT s.datid,
d.datname,
s.pid,
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 0a35f2f8f6a..0f38caa0d24 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -119,7 +119,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
# The stats test resets stats, so nothing else needing stats access can be in
# this group.
# ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize stats predicate
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize stats predicate numa
# event_trigger depends on create_am and cannot run concurrently with
# any test that runs DDL
diff --git a/src/test/regress/sql/numa.sql b/src/test/regress/sql/numa.sql
new file mode 100644
index 00000000000..fddb21a260a
--- /dev/null
+++ b/src/test/regress/sql/numa.sql
@@ -0,0 +1,9 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
+\endif
+
+-- switch to superuser
+\c -
+
+SELECT COUNT(*) >= 0 AS ok FROM pg_shmem_numa_allocations;
diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index 286b1d03756..ca51dfd7702 100644
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -1911,8 +1911,8 @@ REVOKE MAINTAIN ON lock_table FROM regress_locktable_user;
DROP TABLE lock_table;
DROP USER regress_locktable_user;
--- test to check privileges of system views pg_shmem_allocations and
--- pg_backend_memory_contexts.
+-- test to check privileges of system views pg_shmem_allocations,
+-- pg_shmem_numa_allocations and pg_backend_memory_contexts.
-- switch to superuser
\c -
@@ -1922,12 +1922,14 @@ CREATE ROLE regress_readallstats;
SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- no
SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- no
SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT'); -- no
+SELECT has_table_privilege('regress_readallstats','pg_shmem_numa_allocations','SELECT'); -- no
GRANT pg_read_all_stats TO regress_readallstats;
SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- yes
SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- yes
SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT'); -- yes
+SELECT has_table_privilege('regress_readallstats','pg_shmem_numa_allocations','SELECT'); -- yes
-- run query to ensure that functions within views can be executed
SET ROLE regress_readallstats;
--
2.39.5
From 01a117778b98944ffc50a15777fa023188b4fd45 Mon Sep 17 00:00:00 2001
From: Jakub Wartak <jakub.wartak@enterprisedb.com>
Date: Wed, 19 Mar 2025 09:34:56 +0100
Subject: [PATCH v20 2/4] pg_buffercache: split pg_buffercache_pages into parts
Split pg_buffercache_pages() into multiple smaller functions, to allow
reuse in future patches. This introduces three new functions:
- pg_buffercache_init_entries
- pg_buffercache_build_tuple
- get_buffercache_tuple
that help adding entries into a tuplestore, describing the contents of
the buffercache.
This is a preparation for future patches extending pg_buffercache, e.g.
to add NUMA observabitily.
Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com
---
contrib/pg_buffercache/pg_buffercache_pages.c | 293 +++++++++---------
1 file changed, 155 insertions(+), 138 deletions(-)
diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index 62602af1775..ced4ec777a1 100644
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -68,80 +68,171 @@ PG_FUNCTION_INFO_V1(pg_buffercache_summary);
PG_FUNCTION_INFO_V1(pg_buffercache_usage_counts);
PG_FUNCTION_INFO_V1(pg_buffercache_evict);
-Datum
-pg_buffercache_pages(PG_FUNCTION_ARGS)
+/*
+ * Helper routine for pg_buffercache_pages().
+ */
+static BufferCachePagesContext *
+pg_buffercache_init_entries(FuncCallContext *funcctx, FunctionCallInfo fcinfo)
{
- FuncCallContext *funcctx;
- Datum result;
- MemoryContext oldcontext;
BufferCachePagesContext *fctx; /* User function context. */
+ MemoryContext oldcontext;
TupleDesc tupledesc;
TupleDesc expected_tupledesc;
- HeapTuple tuple;
- if (SRF_IS_FIRSTCALL())
- {
- int i;
+ /* Switch context when allocating stuff to be used in later calls */
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
- funcctx = SRF_FIRSTCALL_INIT();
+ /* Create a user function context for cross-call persistence */
+ fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
+
+ /*
+ * To smoothly support upgrades from version 1.0 of this extension
+ * transparently handle the (non-)existence of the pinning_backends
+ * column. We unfortunately have to get the result type for that... - we
+ * can't use the result type determined by the function definition without
+ * potentially crashing when somebody uses the old (or even wrong)
+ * function definition though.
+ */
+ if (get_call_result_type(fcinfo, NULL, &expected_tupledesc) != TYPEFUNC_COMPOSITE)
+ elog(ERROR, "return type must be a row type");
+
+ if (expected_tupledesc->natts < NUM_BUFFERCACHE_PAGES_MIN_ELEM ||
+ expected_tupledesc->natts > NUM_BUFFERCACHE_PAGES_ELEM)
+ elog(ERROR, "incorrect number of output arguments");
+
+ /* Construct a tuple descriptor for the result rows. */
+ tupledesc = CreateTemplateTupleDesc(expected_tupledesc->natts);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
+ INT4OID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 2, "relfilenode",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 3, "reltablespace",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relforknumber",
+ INT2OID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 6, "relblocknumber",
+ INT8OID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 7, "isdirty",
+ BOOLOID, -1, 0);
+ TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
+ INT2OID, -1, 0);
+
+ if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM)
+ TupleDescInitEntry(tupledesc, (AttrNumber) 9, "pinning_backends",
+ INT4OID, -1, 0);
- /* Switch context when allocating stuff to be used in later calls */
- oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+ fctx->tupdesc = BlessTupleDesc(tupledesc);
- /* Create a user function context for cross-call persistence */
- fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
+ /* Allocate NBuffers worth of BufferCachePagesRec records. */
+ fctx->record = (BufferCachePagesRec *)
+ MemoryContextAllocHuge(CurrentMemoryContext,
+ sizeof(BufferCachePagesRec) * NBuffers);
+
+ /* Set max calls and remember the user function context. */
+ funcctx->max_calls = NBuffers;
+ funcctx->user_fctx = fctx;
+
+ /* Return to original context when allocating transient memory */
+ MemoryContextSwitchTo(oldcontext);
+ return fctx;
+}
+
+/*
+ * Helper routine for pg_buffercache_pages().
+ *
+ * Save buffer cache information for a single buffer.
+ */
+static void
+pg_buffercache_save_tuple(int record_id, BufferCachePagesContext *fctx)
+{
+ BufferDesc *bufHdr;
+ uint32 buf_state;
+ BufferCachePagesRec *bufRecord = &(fctx->record[record_id]);
+
+ bufHdr = GetBufferDescriptor(record_id);
+ /* Lock each buffer header before inspecting. */
+ buf_state = LockBufHdr(bufHdr);
+
+ bufRecord->bufferid = BufferDescriptorGetBuffer(bufHdr);
+ bufRecord->relfilenumber = BufTagGetRelNumber(&bufHdr->tag);
+ bufRecord->reltablespace = bufHdr->tag.spcOid;
+ bufRecord->reldatabase = bufHdr->tag.dbOid;
+ bufRecord->forknum = BufTagGetForkNum(&bufHdr->tag);
+ bufRecord->blocknum = bufHdr->tag.blockNum;
+ bufRecord->usagecount = BUF_STATE_GET_USAGECOUNT(buf_state);
+ bufRecord->pinning_backends = BUF_STATE_GET_REFCOUNT(buf_state);
+
+ if (buf_state & BM_DIRTY)
+ bufRecord->isdirty = true;
+ else
+ bufRecord->isdirty = false;
+
+ /* Note if the buffer is valid, and has storage created */
+ if ((buf_state & BM_VALID) && (buf_state & BM_TAG_VALID))
+ bufRecord->isvalid = true;
+ else
+ bufRecord->isvalid = false;
+
+ UnlockBufHdr(bufHdr, buf_state);
+}
+
+/*
+ * Helper routine for pg_buffercache_pages().
+ *
+ * Format and return a tuple for a single buffer cache entry.
+ */
+static Datum
+get_buffercache_tuple(int record_id, BufferCachePagesContext *fctx)
+{
+ Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
+ bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
+ HeapTuple tuple;
+ BufferCachePagesRec *bufRecord = &(fctx->record[record_id]);
+
+ values[0] = Int32GetDatum(bufRecord->bufferid);
+ memset(nulls, false, NUM_BUFFERCACHE_PAGES_ELEM);
+
+ /*
+ * Set all fields except the bufferid to null if the buffer is unused or
+ * not valid.
+ */
+ if (bufRecord->blocknum == InvalidBlockNumber || bufRecord->isvalid == false)
+ memset(&nulls[1], true, (NUM_BUFFERCACHE_PAGES_ELEM - 1) * sizeof(bool));
+ else
+ {
+ values[1] = ObjectIdGetDatum(bufRecord->relfilenumber);
+ values[2] = ObjectIdGetDatum(bufRecord->reltablespace);
+ values[3] = ObjectIdGetDatum(bufRecord->reldatabase);
+ values[4] = ObjectIdGetDatum(bufRecord->forknum);
+ values[5] = Int64GetDatum((int64) bufRecord->blocknum);
+ values[6] = BoolGetDatum(bufRecord->isdirty);
+ values[7] = Int16GetDatum(bufRecord->usagecount);
/*
- * To smoothly support upgrades from version 1.0 of this extension
- * transparently handle the (non-)existence of the pinning_backends
- * column. We unfortunately have to get the result type for that... -
- * we can't use the result type determined by the function definition
- * without potentially crashing when somebody uses the old (or even
- * wrong) function definition though.
+ * unused for v1.0 callers, but the array is always long enough
*/
- if (get_call_result_type(fcinfo, NULL, &expected_tupledesc) != TYPEFUNC_COMPOSITE)
- elog(ERROR, "return type must be a row type");
+ values[8] = Int32GetDatum(bufRecord->pinning_backends);
+ }
- if (expected_tupledesc->natts < NUM_BUFFERCACHE_PAGES_MIN_ELEM ||
- expected_tupledesc->natts > NUM_BUFFERCACHE_PAGES_ELEM)
- elog(ERROR, "incorrect number of output arguments");
+ /* Build and return the tuple. */
+ tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
+ return HeapTupleGetDatum(tuple);
+}
- /* Construct a tuple descriptor for the result rows. */
- tupledesc = CreateTemplateTupleDesc(expected_tupledesc->natts);
- TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
- INT4OID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 2, "relfilenode",
- OIDOID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 3, "reltablespace",
- OIDOID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
- OIDOID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relforknumber",
- INT2OID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 6, "relblocknumber",
- INT8OID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 7, "isdirty",
- BOOLOID, -1, 0);
- TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
- INT2OID, -1, 0);
-
- if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM)
- TupleDescInitEntry(tupledesc, (AttrNumber) 9, "pinning_backends",
- INT4OID, -1, 0);
-
- fctx->tupdesc = BlessTupleDesc(tupledesc);
-
- /* Allocate NBuffers worth of BufferCachePagesRec records. */
- fctx->record = (BufferCachePagesRec *)
- MemoryContextAllocHuge(CurrentMemoryContext,
- sizeof(BufferCachePagesRec) * NBuffers);
-
- /* Set max calls and remember the user function context. */
- funcctx->max_calls = NBuffers;
- funcctx->user_fctx = fctx;
-
- /* Return to original context when allocating transient memory */
- MemoryContextSwitchTo(oldcontext);
+Datum
+pg_buffercache_pages(PG_FUNCTION_ARGS)
+{
+ FuncCallContext *funcctx;
+ BufferCachePagesContext *fctx; /* User function context. */
+
+ if (SRF_IS_FIRSTCALL())
+ {
+ int i;
+
+ funcctx = SRF_FIRSTCALL_INIT();
+ fctx = pg_buffercache_init_entries(funcctx, fcinfo);
/*
* Scan through all the buffers, saving the relevant fields in the
@@ -152,36 +243,7 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
* locks, so the information of each buffer is self-consistent.
*/
for (i = 0; i < NBuffers; i++)
- {
- 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].relfilenumber = BufTagGetRelNumber(&bufHdr->tag);
- fctx->record[i].reltablespace = bufHdr->tag.spcOid;
- fctx->record[i].reldatabase = bufHdr->tag.dbOid;
- fctx->record[i].forknum = BufTagGetForkNum(&bufHdr->tag);
- 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);
- }
+ pg_buffercache_save_tuple(i, fctx);
}
funcctx = SRF_PERCALL_SETUP();
@@ -191,55 +253,10 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
if (funcctx->call_cntr < funcctx->max_calls)
{
+ Datum result;
uint32 i = funcctx->call_cntr;
- Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
- bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
-
- values[0] = Int32GetDatum(fctx->record[i].bufferid);
- nulls[0] = false;
-
- /*
- * Set all fields except the bufferid to null if the buffer is unused
- * or not valid.
- */
- if (fctx->record[i].blocknum == InvalidBlockNumber ||
- fctx->record[i].isvalid == false)
- {
- nulls[1] = true;
- nulls[2] = true;
- nulls[3] = true;
- nulls[4] = true;
- nulls[5] = true;
- nulls[6] = true;
- nulls[7] = true;
- /* unused for v1.0 callers, but the array is always long enough */
- nulls[8] = true;
- }
- else
- {
- values[1] = ObjectIdGetDatum(fctx->record[i].relfilenumber);
- nulls[1] = false;
- values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
- nulls[2] = false;
- values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
- nulls[3] = false;
- values[4] = ObjectIdGetDatum(fctx->record[i].forknum);
- nulls[4] = false;
- values[5] = Int64GetDatum((int64) fctx->record[i].blocknum);
- nulls[5] = false;
- values[6] = BoolGetDatum(fctx->record[i].isdirty);
- nulls[6] = false;
- values[7] = Int16GetDatum(fctx->record[i].usagecount);
- nulls[7] = false;
- /* unused for v1.0 callers, but the array is always long enough */
- values[8] = Int32GetDatum(fctx->record[i].pinning_backends);
- nulls[8] = false;
- }
-
- /* Build and return the tuple. */
- tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
- result = HeapTupleGetDatum(tuple);
+ result = get_buffercache_tuple(i, fctx);
SRF_RETURN_NEXT(funcctx, result);
}
else
--
2.39.5
From ce5242a248155e1e18e7b3a3abc38a26bc5537d1 Mon Sep 17 00:00:00 2001
From: Jakub Wartak <jakub.wartak@enterprisedb.com>
Date: Wed, 19 Mar 2025 09:34:56 +0100
Subject: [PATCH v20 3/4] Add pg_buffercache_numa view with NUMA node info
Introduces a new view pg_buffercache_numa, showing a NUMA memory node
for each individual buffer.
To determine the NUMA node for a buffer, we first need to touch the
memory pages using pg_numa_touch_mem_if_required, otherwise we might get
status -2 (ENOENT = The page is not present), indicating the page is
either unmapped or unallocated.
The size of a database block and OS memory page may differ. For example
the default block size (BLCKSZ) sis 8KB, while the memory page is 4KB,
but it's also possible to make the block size smaller (e.g. 1KB). It's
enough to query the NUMA node only once per memory page, we don't need
to repeat this for every buffer.
Right now we just report NUMA node of the first page when dealing with
multiple pages per single buffer.
Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com
---
contrib/pg_buffercache/Makefile | 3 +-
.../expected/pg_buffercache_numa.out | 28 +++
.../expected/pg_buffercache_numa_1.out | 3 +
contrib/pg_buffercache/meson.build | 2 +
.../pg_buffercache--1.5--1.6.sql | 24 +++
contrib/pg_buffercache/pg_buffercache.control | 2 +-
contrib/pg_buffercache/pg_buffercache_pages.c | 187 +++++++++++++++++-
.../sql/pg_buffercache_numa.sql | 20 ++
doc/src/sgml/pgbuffercache.sgml | 61 +++++-
9 files changed, 322 insertions(+), 8 deletions(-)
create mode 100644 contrib/pg_buffercache/expected/pg_buffercache_numa.out
create mode 100644 contrib/pg_buffercache/expected/pg_buffercache_numa_1.out
create mode 100644 contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql
create mode 100644 contrib/pg_buffercache/sql/pg_buffercache_numa.sql
diff --git a/contrib/pg_buffercache/Makefile b/contrib/pg_buffercache/Makefile
index eae65ead9e5..2a33602537e 100644
--- a/contrib/pg_buffercache/Makefile
+++ b/contrib/pg_buffercache/Makefile
@@ -8,7 +8,8 @@ OBJS = \
EXTENSION = pg_buffercache
DATA = pg_buffercache--1.2.sql pg_buffercache--1.2--1.3.sql \
pg_buffercache--1.1--1.2.sql pg_buffercache--1.0--1.1.sql \
- pg_buffercache--1.3--1.4.sql pg_buffercache--1.4--1.5.sql
+ pg_buffercache--1.3--1.4.sql pg_buffercache--1.4--1.5.sql \
+ pg_buffercache--1.5--1.6.sql
PGFILEDESC = "pg_buffercache - monitoring of shared buffer cache in real-time"
REGRESS = pg_buffercache
diff --git a/contrib/pg_buffercache/expected/pg_buffercache_numa.out b/contrib/pg_buffercache/expected/pg_buffercache_numa.out
new file mode 100644
index 00000000000..d4de5ea52fc
--- /dev/null
+++ b/contrib/pg_buffercache/expected/pg_buffercache_numa.out
@@ -0,0 +1,28 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
+\endif
+select count(*) = (select setting::bigint
+ from pg_settings
+ where name = 'shared_buffers')
+from pg_buffercache_numa;
+ ?column?
+----------
+ t
+(1 row)
+
+-- Check that the functions / views can't be accessed by default. To avoid
+-- having to create a dedicated user, use the pg_database_owner pseudo-role.
+SET ROLE pg_database_owner;
+SELECT count(*) > 0 FROM pg_buffercache_numa;
+ERROR: permission denied for view pg_buffercache_numa
+RESET role;
+-- Check that pg_monitor is allowed to query view / function
+SET ROLE pg_monitor;
+SELECT count(*) > 0 FROM pg_buffercache_numa;
+ ?column?
+----------
+ t
+(1 row)
+
+RESET role;
diff --git a/contrib/pg_buffercache/expected/pg_buffercache_numa_1.out b/contrib/pg_buffercache/expected/pg_buffercache_numa_1.out
new file mode 100644
index 00000000000..6dd6824b4e4
--- /dev/null
+++ b/contrib/pg_buffercache/expected/pg_buffercache_numa_1.out
@@ -0,0 +1,3 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
diff --git a/contrib/pg_buffercache/meson.build b/contrib/pg_buffercache/meson.build
index 12d1fe48717..7cd039a1df9 100644
--- a/contrib/pg_buffercache/meson.build
+++ b/contrib/pg_buffercache/meson.build
@@ -23,6 +23,7 @@ install_data(
'pg_buffercache--1.2.sql',
'pg_buffercache--1.3--1.4.sql',
'pg_buffercache--1.4--1.5.sql',
+ 'pg_buffercache--1.5--1.6.sql',
'pg_buffercache.control',
kwargs: contrib_data_args,
)
@@ -34,6 +35,7 @@ tests += {
'regress': {
'sql': [
'pg_buffercache',
+ 'pg_buffercache_numa',
],
},
}
diff --git a/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql b/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql
new file mode 100644
index 00000000000..8c1e891eab2
--- /dev/null
+++ b/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql
@@ -0,0 +1,24 @@
+/* contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION pg_buffercache UPDATE TO '1.6'" to load this file. \quit
+
+-- Register the new functions.
+CREATE OR REPLACE FUNCTION pg_buffercache_numa_pages()
+RETURNS SETOF RECORD
+AS 'MODULE_PATHNAME', 'pg_buffercache_numa_pages'
+LANGUAGE C PARALLEL SAFE;
+
+-- Create a view for convenient access.
+CREATE OR REPLACE VIEW pg_buffercache_numa AS
+ SELECT P.* FROM pg_buffercache_numa_pages() AS P
+ (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
+ relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2,
+ pinning_backends int4, node_id int4);
+
+-- Don't want these to be available to public.
+REVOKE ALL ON FUNCTION pg_buffercache_numa_pages() FROM PUBLIC;
+REVOKE ALL ON pg_buffercache_numa FROM PUBLIC;
+
+GRANT EXECUTE ON FUNCTION pg_buffercache_numa_pages() TO pg_monitor;
+GRANT SELECT ON pg_buffercache_numa TO pg_monitor;
diff --git a/contrib/pg_buffercache/pg_buffercache.control b/contrib/pg_buffercache/pg_buffercache.control
index 5ee875f77dd..b030ba3a6fa 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 = '1.5'
+default_version = '1.6'
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 ced4ec777a1..2f2db4c1634 100644
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -11,12 +11,13 @@
#include "access/htup_details.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
+#include "port/pg_numa.h"
#include "storage/buf_internals.h"
#include "storage/bufmgr.h"
#define NUM_BUFFERCACHE_PAGES_MIN_ELEM 8
-#define NUM_BUFFERCACHE_PAGES_ELEM 9
+#define NUM_BUFFERCACHE_PAGES_ELEM 10
#define NUM_BUFFERCACHE_SUMMARY_ELEM 5
#define NUM_BUFFERCACHE_USAGE_COUNTS_ELEM 4
@@ -46,6 +47,7 @@ typedef struct
* because of bufmgr.c's PrivateRefCount infrastructure.
*/
int32 pinning_backends;
+ int32 numa_node_id;
} BufferCachePagesRec;
@@ -64,12 +66,67 @@ typedef struct
* relation node/tablespace/database/blocknum and dirty indicator.
*/
PG_FUNCTION_INFO_V1(pg_buffercache_pages);
+PG_FUNCTION_INFO_V1(pg_buffercache_numa_pages);
PG_FUNCTION_INFO_V1(pg_buffercache_summary);
PG_FUNCTION_INFO_V1(pg_buffercache_usage_counts);
PG_FUNCTION_INFO_V1(pg_buffercache_evict);
+/* Only need to touch memory once per backend process lifetime */
+static bool firstNumaTouch = true;
+
/*
- * Helper routine for pg_buffercache_pages().
+ * Helper routine to map Buffers into addresses that is used by
+ * pg_numa_query_pages(). Please see it's comment for explanation why we need to
+ * prepare pointers like this.
+ *
+ * When database block size (BLCKSZ) is smaller than the OS page size (4kB),
+ * multiple database buffers will map to the same OS memory page. In this case,
+ * we only need to query the NUMA node for the first memory address of each
+ * unique OS page rather than for every buffer.
+ *
+ * In order to get reliable results we also need to touch memory pages, so that
+ * inquiry about NUMA memory node doesn't return -2 (which indicates
+ * unmapped/unallocated pages).
+ *
+ * review: It's not very obvious to me what this does, exactly. I mean, what's
+ * the result in os_page_ptrs? What if BLCKSZ < PAGESIZE or BLCKSZ > PAGESIZE?
+ * What's blk2page and blk2pageoff?
+ */
+static inline void
+pg_buffercache_numa_prepare_ptrs(int buffer_id, double pages_per_blk,
+ Size os_page_size,
+ void **os_page_ptrs)
+{
+ size_t blk2page = (size_t) (buffer_id * pages_per_blk);
+
+ for (size_t j = 0; j < pages_per_blk; j++)
+ {
+ size_t blk2pageoff = blk2page + j;
+
+ if (os_page_ptrs[blk2pageoff] == 0)
+ {
+ volatile uint64 touch pg_attribute_unused();
+
+ /* NBuffers starts from 1 */
+ os_page_ptrs[blk2pageoff] = (char *) BufferGetBlock(buffer_id + 1) +
+ (os_page_size * j);
+
+ /* Only need to touch memory once per backend process lifetime */
+ if (firstNumaTouch)
+ pg_numa_touch_mem_if_required(touch, os_page_ptrs[blk2pageoff]);
+
+ }
+
+ CHECK_FOR_INTERRUPTS();
+ }
+}
+
+/*
+ * Helper routine for pg_buffercache_pages() and pg_buffercache_numa_pages().
+ *
+ * Allocates and returns new user function context based on SRF context
+ * (requires that functx to be initalized by SRF_FIRSTCALL_INIT()) and
+ * standard function call info.
*/
static BufferCachePagesContext *
pg_buffercache_init_entries(FuncCallContext *funcctx, FunctionCallInfo fcinfo)
@@ -119,9 +176,12 @@ pg_buffercache_init_entries(FuncCallContext *funcctx, FunctionCallInfo fcinfo)
TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
INT2OID, -1, 0);
- if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM)
+ if (expected_tupledesc->natts >= NUM_BUFFERCACHE_PAGES_ELEM - 1)
TupleDescInitEntry(tupledesc, (AttrNumber) 9, "pinning_backends",
INT4OID, -1, 0);
+ if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM)
+ TupleDescInitEntry(tupledesc, (AttrNumber) 10, "node_id",
+ INT4OID, -1, 0);
fctx->tupdesc = BlessTupleDesc(tupledesc);
@@ -140,7 +200,7 @@ pg_buffercache_init_entries(FuncCallContext *funcctx, FunctionCallInfo fcinfo)
}
/*
- * Helper routine for pg_buffercache_pages().
+ * Helper routine for pg_buffercache_pages() and pg_buffercache_numa_pages().
*
* Save buffer cache information for a single buffer.
*/
@@ -175,11 +235,13 @@ pg_buffercache_save_tuple(int record_id, BufferCachePagesContext *fctx)
else
bufRecord->isvalid = false;
+ bufRecord->numa_node_id = -1;
+
UnlockBufHdr(bufHdr, buf_state);
}
/*
- * Helper routine for pg_buffercache_pages().
+ * Helper routine for pg_buffercache_pages() and pg_buffercache_numa_pages().
*
* Format and return a tuple for a single buffer cache entry.
*/
@@ -214,6 +276,7 @@ get_buffercache_tuple(int record_id, BufferCachePagesContext *fctx)
* unused for v1.0 callers, but the array is always long enough
*/
values[8] = Int32GetDatum(bufRecord->pinning_backends);
+ values[9] = Int32GetDatum(bufRecord->numa_node_id);
}
/* Build and return the tuple. */
@@ -263,6 +326,120 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
SRF_RETURN_DONE(funcctx);
}
+/*
+ * This is almost identical to the above, but performs
+ * NUMA inquiry about memory mappings.
+ */
+Datum
+pg_buffercache_numa_pages(PG_FUNCTION_ARGS)
+{
+ FuncCallContext *funcctx;
+ BufferCachePagesContext *fctx; /* User function context. */
+
+ if (SRF_IS_FIRSTCALL())
+ {
+ int i;
+ Size os_page_size = 0;
+ void **os_page_ptrs = NULL;
+ int *os_pages_status = NULL;
+ uint64 os_page_count = 0;
+ double pages_per_blk = 0;
+
+ funcctx = SRF_FIRSTCALL_INIT();
+
+ if (pg_numa_init() == -1)
+ elog(ERROR, "libnuma initialization failed or NUMA is not supported on this platform");
+
+ fctx = pg_buffercache_init_entries(funcctx, fcinfo);
+
+ /*
+ * Different database block sizes (4kB, 8kB, ..., 32kB) can be used,
+ * while the OS may have different memory page sizes.
+ *
+ * To correctly map between them, we need to: 1. Determine the OS
+ * memory page size 2. Calculate how many OS pages are used by all
+ * buffer blocks 3. Calculate how many OS pages are contained within
+ * each database block.
+ *
+ * This information is needed before calling move_pages() for NUMA
+ * node id inquiry.
+ */
+ os_page_size = pg_numa_get_pagesize();
+ os_page_count = ((uint64) NBuffers * BLCKSZ) / os_page_size;
+ pages_per_blk = (double) BLCKSZ / os_page_size;
+
+ elog(DEBUG1, "NUMA: os_page_count=" UINT64_FORMAT " os_page_size=%zu pages_per_blk=%.6f",
+ os_page_count, os_page_size, pages_per_blk);
+
+ os_page_ptrs = palloc0(sizeof(void *) * os_page_count);
+ os_pages_status = palloc(sizeof(uint64) * os_page_count);
+
+ /*
+ * If we ever get 0xff back from kernel inquiry, then we probably have
+ * bug in our buffers to OS page mapping code here.
+ *
+ */
+ memset(os_pages_status, 0xff, sizeof(int) * os_page_count);
+
+ if (firstNumaTouch)
+ elog(DEBUG1, "NUMA: page-faulting the buffercache for proper NUMA readouts");
+
+ /*
+ * Scan through all the buffers, saving the relevant fields in the
+ * fctx->record structure.
+ *
+ * We don't hold the partition locks, so we don't get a consistent
+ * snapshot across all buffers, but we do grab the buffer header
+ * locks, so the information of each buffer is self-consistent.
+ */
+ for (i = 0; i < NBuffers; i++)
+ {
+ pg_buffercache_save_tuple(i, fctx);
+ pg_buffercache_numa_prepare_ptrs(i, pages_per_blk, os_page_size,
+ os_page_ptrs);
+ }
+
+ if (pg_numa_query_pages(0, os_page_count, os_page_ptrs, os_pages_status) == -1)
+ elog(ERROR, "failed NUMA pages inquiry: %m");
+
+ for (i = 0; i < NBuffers; i++)
+ {
+ size_t blk2page = (size_t) i * pages_per_blk;
+
+ /*
+ * Set the NUMA node id for this buffer based on the first OS page
+ * it maps to.
+ *
+ * Note: We could check for errors in os_pages_status and report
+ * them. Also, a single DB block might span multiple NUMA nodes if
+ * it crosses OS pages on node boundaries, but we only record the
+ * node of the first page. This is a simplification but should be
+ * sufficient for most analyses.
+ */
+ fctx->record[i].numa_node_id = os_pages_status[blk2page];
+ }
+ }
+
+ funcctx = SRF_PERCALL_SETUP();
+
+ /* Get the saved state */
+ fctx = funcctx->user_fctx;
+
+ if (funcctx->call_cntr < funcctx->max_calls)
+ {
+ Datum result;
+ uint32 i = funcctx->call_cntr;
+
+ result = get_buffercache_tuple(i, fctx);
+ SRF_RETURN_NEXT(funcctx, result);
+ }
+ else
+ {
+ firstNumaTouch = false;
+ SRF_RETURN_DONE(funcctx);
+ }
+}
+
Datum
pg_buffercache_summary(PG_FUNCTION_ARGS)
{
diff --git a/contrib/pg_buffercache/sql/pg_buffercache_numa.sql b/contrib/pg_buffercache/sql/pg_buffercache_numa.sql
new file mode 100644
index 00000000000..2225b879f58
--- /dev/null
+++ b/contrib/pg_buffercache/sql/pg_buffercache_numa.sql
@@ -0,0 +1,20 @@
+SELECT NOT(pg_numa_available()) AS skip_test \gset
+\if :skip_test
+\quit
+\endif
+
+select count(*) = (select setting::bigint
+ from pg_settings
+ where name = 'shared_buffers')
+from pg_buffercache_numa;
+
+-- Check that the functions / views can't be accessed by default. To avoid
+-- having to create a dedicated user, use the pg_database_owner pseudo-role.
+SET ROLE pg_database_owner;
+SELECT count(*) > 0 FROM pg_buffercache_numa;
+RESET role;
+
+-- Check that pg_monitor is allowed to query view / function
+SET ROLE pg_monitor;
+SELECT count(*) > 0 FROM pg_buffercache_numa;
+RESET role;
diff --git a/doc/src/sgml/pgbuffercache.sgml b/doc/src/sgml/pgbuffercache.sgml
index 802a5112d77..315227bf0ce 100644
--- a/doc/src/sgml/pgbuffercache.sgml
+++ b/doc/src/sgml/pgbuffercache.sgml
@@ -30,7 +30,9 @@
<para>
This module provides the <function>pg_buffercache_pages()</function>
function (wrapped in the <structname>pg_buffercache</structname> view),
- the <function>pg_buffercache_summary()</function> function, the
+ <function>pg_buffercache_numa_pages()</function> function (wrapped in the
+ <structname>pg_buffercache_numa</structname> view), the
+ <function>pg_buffercache_summary()</function> function, the
<function>pg_buffercache_usage_counts()</function> function and
the <function>pg_buffercache_evict()</function> function.
</para>
@@ -42,6 +44,14 @@
convenient use.
</para>
+ <para>
+ The <function>pg_buffercache_numa_pages()</function> provides the same information
+ as <function>pg_buffercache_pages()</function> but is slower because it also
+ provides the <acronym>NUMA</acronym> node ID per shared buffer entry.
+ The <structname>pg_buffercache_numa</structname> view wraps the function for
+ convenient use.
+ </para>
+
<para>
The <function>pg_buffercache_summary()</function> function returns a single
row summarizing the state of the shared buffer cache.
@@ -200,6 +210,55 @@
</para>
</sect2>
+ <sect2 id="pgbuffercache-pg-buffercache-numa">
+ <title>The <structname>pg_buffercache_numa</structname> View</title>
+
+ <para>
+ The definitions of the columns exposed are identical to the
+ <structname>pg_buffercache</structname> view, except that this one includes
+ one additional <structfield>node_id</structfield> column as defined in
+ <xref linkend="pgbuffercache-numa-columns"/>.
+ </para>
+
+ <table id="pgbuffercache-numa-columns">
+ <title><structname>pg_buffercache_numa</structname> Extra column</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>node_id</structfield> <type>integer</type>
+ </para>
+ <para>
+ <acronym>NUMA</acronym> node ID. NULL if the shared buffer
+ has not been used yet. On systems without <acronym>NUMA</acronym> support
+ this returns 0.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
+ <para>
+ As <acronym>NUMA</acronym> node ID inquiry for each page requires memory pages
+ to be paged-in, the first execution of this function can take a noticeable
+ amount of time. In all the cases (first execution or not), retrieving this
+ information is costly and querying the view at a high frequency is not recommended.
+ </para>
+
+ </sect2>
+
<sect2 id="pgbuffercache-summary">
<title>The <function>pg_buffercache_summary()</function> Function</title>
--
2.39.5
