public inbox for [email protected]
help / color / mirror / Atom feedFrom: Bossart, Nathan <[email protected]>
To: Michael Paquier <[email protected]>
Cc: Justin Pryzby <[email protected]>
Cc: Andres Freund <[email protected]>
Cc: Magnus Hagander <[email protected]>
Cc: Mark Dilger <[email protected]>
Cc: Don Seiler <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: Estimating HugePages Requirements?
Date: Mon, 6 Sep 2021 23:55:42 +0000
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
On 9/5/21, 9:26 PM, "Bossart, Nathan" <[email protected]> wrote:
> On 9/5/21, 7:28 PM, "Michael Paquier" <[email protected]> wrote:
>> Without concluding on 0002 yet, another thing that we could do is to
>> just add the GUCs. These sound rather useful on their own (mixed
>> feelings about huge_pages_required but I can see why it is useful to
>> avoid the setup steps and the backend already grabs this information),
>> particularly when it comes to cloned setups that share a lot of
>> properties.
>
> I think this is a good starting point, but I'd like to follow up on
> making them visible without completely starting the server. The main
> purpose for adding these GUCs is to be able to set up huge pages
> before server startup. Disallowing "-C huge_pages_required" on a
> running server to enable this use-case seems like a modest tradeoff.
>
> Anyway, I'll restructure the remaining patches to add the GUCs first
> and then address the 0002 business separately.
Attached is a new patch set. The first two patches just add the new
GUCs, and the third is an attempt at providing useful values for those
GUCs via -C.
Nathan
Attachments:
[application/octet-stream] v6-0003-Provide-useful-values-for-postgres-C-with-runtime.patch (10.3K, 2-v6-0003-Provide-useful-values-for-postgres-C-with-runtime.patch)
download | inline diff:
From bce822ac162a63be8ece7ee035539d7951170b3e Mon Sep 17 00:00:00 2001
From: Nathan Bossart <[email protected]>
Date: Mon, 6 Sep 2021 23:31:41 +0000
Subject: [PATCH v6 3/3] Provide useful values for 'postgres -C' with
runtime-computed GUCs.
The -C option is handled before a small subset of GUCs that are
computed at runtime are initialized. Unfortunately, we cannot move
this handling to after they are initialized without disallowing
'postgres -C' on a running server. One notable reason for this is
that loadable libraries' _PG_init() functions are called before all
runtime-computed GUCs are initialized, and this is not guaranteed
to be safe to do on running servers.
In order to provide useful values for 'postgres -C' for runtime-
computed GUCs, this change adds a new section for handling just
these GUCs just before shared memory is initialized. While users
won't be able to use -C for runtime-computed GUCs on running
servers, providing a useful value with this restriction seems
better than not providing a useful value at all.
---
doc/src/sgml/ref/postgres-ref.sgml | 10 ++++++--
doc/src/sgml/runtime.sgml | 33 ++++++++----------------
src/backend/postmaster/postmaster.c | 50 +++++++++++++++++++++++++++++++------
src/backend/utils/misc/guc.c | 10 ++++----
src/include/utils/guc.h | 6 +++++
5 files changed, 73 insertions(+), 36 deletions(-)
diff --git a/doc/src/sgml/ref/postgres-ref.sgml b/doc/src/sgml/ref/postgres-ref.sgml
index 4aaa7abe1a..f6f2246bff 100644
--- a/doc/src/sgml/ref/postgres-ref.sgml
+++ b/doc/src/sgml/ref/postgres-ref.sgml
@@ -133,13 +133,19 @@ PostgreSQL documentation
<listitem>
<para>
Prints the value of the named run-time parameter, and exits.
- (See the <option>-c</option> option above for details.) This can
- be used on a running server, and returns values from
+ (See the <option>-c</option> option above for details.) This
+ returns values from
<filename>postgresql.conf</filename>, modified by any parameters
supplied in this invocation. It does not reflect parameters
supplied when the cluster was started.
</para>
+ <para>
+ This can be used on a running server for most parameters. However,
+ the server must be shut down for some runtime-computed parameters
+ (e.g., <xref linkend="guc-huge-pages-required"/>).
+ </para>
+
<para>
This option is meant for other programs that interact with a server
instance, such as <xref linkend="app-pg-ctl"/>, to query configuration
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index f1cbc1d9e9..d955639900 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1442,32 +1442,21 @@ export PG_OOM_ADJUST_VALUE=0
with <varname>CONFIG_HUGETLBFS=y</varname> and
<varname>CONFIG_HUGETLB_PAGE=y</varname>. You will also have to configure
the operating system to provide enough huge pages of the desired size.
- To estimate the number of huge pages needed, start
- <productname>PostgreSQL</productname> without huge pages enabled and check
- the postmaster's anonymous shared memory segment size, as well as the
- system's default and supported huge page sizes, using the
- <filename>/proc</filename> and <filename>/sys</filename> file systems.
- This might look like:
+ To estimate the number of huge pages needed, use the
+ <command>postgres</command> command to see the value of
+ <xref linkend="guc-huge-pages-required"/>. This might look like:
<programlisting>
-$ <userinput>head -1 $PGDATA/postmaster.pid</userinput>
-4170
-$ <userinput>pmap 4170 | awk '/rw-s/ && /zero/ {print $2}'</userinput>
-6490428K
-$ <userinput>grep ^Hugepagesize /proc/meminfo</userinput>
-Hugepagesize: 2048 kB
-$ <userinput>ls /sys/kernel/mm/hugepages</userinput>
-hugepages-1048576kB hugepages-2048kB
+$ <userinput>postgres -D $PGDATA -C huge_pages_required</userinput>
+3170
</programlisting>
- In this example the default is 2MB, but you can also explicitly request
- either 2MB or 1GB with <xref linkend="guc-huge-page-size"/>.
+ Note that you can explicitly request either 2MB or 1GB huge pages with
+ <xref linkend="guc-huge-page-size"/>.
- Assuming <literal>2MB</literal> huge pages,
- <literal>6490428</literal> / <literal>2048</literal> gives approximately
- <literal>3169.154</literal>, so in this example we need at
- least <literal>3170</literal> huge pages. A larger setting would be
- appropriate if other programs on the machine also need huge pages.
- We can set this with:
+ While we need at least <literal>3170</literal> huge pages in this
+ example, a larger setting would be appropriate if other programs on
+ the machine also need huge pages. We can allocate the huge pages
+ with:
<programlisting>
# <userinput>sysctl -w vm.nr_hugepages=3170</userinput>
</programlisting>
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 963c03fa93..d3cbb14d33 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -896,15 +896,31 @@ PostmasterMain(int argc, char *argv[])
if (output_config_variable != NULL)
{
/*
- * "-C guc" was specified, so print GUC's value and exit. No extra
- * permission check is needed because the user is reading inside the
- * data dir.
+ * If this is a runtime-computed GUC, it hasn't yet been initialized,
+ * and the present value is not useful. However, this is a convenient
+ * place to print the value for most GUCs because it is safe to run
+ * postmaster startup to this point even if the server is already
+ * running. For the handful of runtime-computed GUCs that we can't
+ * provide meaningful values for yet, we wait until later in postmaster
+ * startup to print the value. We won't be able to use -C on running
+ * servers for those GUCs, but otherwise this option is unusable for
+ * them.
*/
- const char *config_val = GetConfigOption(output_config_variable,
- false, false);
+ int flags = GetConfigOptionFlags(output_config_variable, true);
- puts(config_val ? config_val : "");
- ExitPostmaster(0);
+ if ((flags & GUC_RUNTIME_COMPUTED) == 0)
+ {
+ /*
+ * "-C guc" was specified, so print GUC's value and exit. No extra
+ * permission check is needed because the user is reading inside
+ * the data dir.
+ */
+ const char *config_val = GetConfigOption(output_config_variable,
+ false, false);
+
+ puts(config_val ? config_val : "");
+ ExitPostmaster(0);
+ }
}
/* Verify that DataDir looks reasonable */
@@ -1033,6 +1049,26 @@ PostmasterMain(int argc, char *argv[])
*/
InitializeShmemGUCs();
+ /*
+ * If -C was specified with a runtime-computed GUC, we held off printing
+ * the value earlier, as the GUC was not yet initialized. We handle -C for
+ * most GUCs before we lock the data directory so that the option may be
+ * used on a running server. However, a handful of GUCs are runtime-
+ * computed and do not have meaningful values until after locking the data
+ * directory, and we cannot safely calculate their values earlier on a
+ * running server. At this point, such GUCs should be properly
+ * initialized, and we haven't yet set up shared memory, so this is a good
+ * time to handle the -C option for these special GUCs.
+ */
+ if (output_config_variable != NULL)
+ {
+ const char *config_val = GetConfigOption(output_config_variable,
+ false, false);
+
+ puts(config_val ? config_val : "");
+ ExitPostmaster(0);
+ }
+
/*
* Set up shared memory and semaphores.
*/
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 1a30d635fc..cabbd083d9 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1985,7 +1985,7 @@ static struct config_bool ConfigureNamesBool[] =
{"data_checksums", PGC_INTERNAL, PRESET_OPTIONS,
gettext_noop("Shows whether data checksums are turned on for this cluster."),
NULL,
- GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
},
&data_checksums,
false,
@@ -2230,7 +2230,7 @@ static struct config_int ConfigureNamesInt[] =
{"huge_pages_required", PGC_INTERNAL, RESOURCES_MEM,
gettext_noop("Shows the number of huge pages needed for the main shared memory area."),
gettext_noop("-1 indicates that the value could not be determined."),
- GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
},
&huge_pages_required,
-1, -1, INT_MAX,
@@ -2355,7 +2355,7 @@ static struct config_int ConfigureNamesInt[] =
{"shared_memory_size", PGC_INTERNAL, RESOURCES_MEM,
gettext_noop("Shows the size of the server's main shared memory area (rounded up to the nearest MB)."),
NULL,
- GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_UNIT_MB
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_UNIT_MB | GUC_RUNTIME_COMPUTED
},
&shmem_size_mb,
0, 0, INT_MAX,
@@ -2420,7 +2420,7 @@ static struct config_int ConfigureNamesInt[] =
"in the form accepted by the chmod and umask system "
"calls. (To use the customary octal format the number "
"must start with a 0 (zero).)"),
- GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
},
&data_directory_mode,
0700, 0000, 0777,
@@ -3244,7 +3244,7 @@ static struct config_int ConfigureNamesInt[] =
{"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
gettext_noop("Shows the size of write ahead log segments."),
NULL,
- GUC_UNIT_BYTE | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ GUC_UNIT_BYTE | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
},
&wal_segment_size,
DEFAULT_XLOG_SEG_SIZE,
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index a7c3a4958e..aa18d304ac 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -229,6 +229,12 @@ typedef enum
#define GUC_EXPLAIN 0x100000 /* include in explain */
+/*
+ * GUC_RUNTIME_COMPUTED is intended for runtime-computed GUCs that are only
+ * available via 'postgres -C' if the server is not running.
+ */
+#define GUC_RUNTIME_COMPUTED 0x200000
+
#define GUC_UNIT (GUC_UNIT_MEMORY | GUC_UNIT_TIME)
--
2.16.6
[application/octet-stream] v6-0002-Introduce-huge_pages_required-GUC.patch (5.0K, 3-v6-0002-Introduce-huge_pages_required-GUC.patch)
download | inline diff:
From 6010e5bc8c1574a982d4cec2cc323f972f553071 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <[email protected]>
Date: Mon, 6 Sep 2021 18:04:59 +0000
Subject: [PATCH v6 2/3] Introduce huge_pages_required GUC.
This runtime-computed GUC shows the number of huge pages required
for the server's main shared memory area. Like shared_memory_size,
it cannot be viewed with 'postgres -C' yet.
---
doc/src/sgml/config.sgml | 21 +++++++++++++++++++++
src/backend/port/sysv_shmem.c | 2 +-
src/backend/storage/ipc/ipci.c | 20 ++++++++++++++++++++
src/backend/utils/misc/guc.c | 12 ++++++++++++
src/include/storage/pg_shmem.h | 4 ++++
5 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index ef0e2a7746..b27d8aff15 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10101,6 +10101,27 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-huge-pages-required" xreflabel="huge_pages_required">
+ <term><varname>huge_pages_required</varname> (<type>integer</type>)
+ <indexterm>
+ <primary><varname>huge_pages_required</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Reports the number of huge pages that are required for the main
+ shared memory area based on the specified
+ <xref linkend="guc-huge-page-size"/>. If huge pages are not supported,
+ this will be <literal>-1</literal>.
+ </para>
+ <para>
+ This setting is supported only on Linux. It is always set to
+ <literal>-1</literal> on other platforms. For more details about using
+ huge pages on Linux, see <xref linkend="linux-huge-pages"/>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-integer-datetimes" xreflabel="integer_datetimes">
<term><varname>integer_datetimes</varname> (<type>boolean</type>)
<indexterm>
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c
index 9de96edf6a..f42f1ac171 100644
--- a/src/backend/port/sysv_shmem.c
+++ b/src/backend/port/sysv_shmem.c
@@ -478,7 +478,7 @@ PGSharedMemoryAttach(IpcMemoryId shmId,
* Returns the (real, assumed or config provided) page size into *hugepagesize,
* and the hugepage-related mmap flags to use into *mmap_flags.
*/
-static void
+void
GetHugePageSize(Size *hugepagesize, int *mmap_flags)
{
Size default_hugepagesize = 0;
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 614b8e92c4..e5f94f9e69 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -14,6 +14,10 @@
*/
#include "postgres.h"
+#ifndef WIN32
+#include <sys/mman.h>
+#endif
+
#include "access/clog.h"
#include "access/commit_ts.h"
#include "access/heapam.h"
@@ -326,6 +330,11 @@ InitializeShmemGUCs(void)
char buf[64];
Size size_b;
Size size_mb;
+#if defined(MAP_HUGETLB)
+ Size hp_size;
+ Size hp_required;
+ int unused;
+#endif
/*
* Calculate the shared memory size and round up to the nearest
@@ -336,4 +345,15 @@ InitializeShmemGUCs(void)
sprintf(buf, "%lu MB", size_mb);
SetConfigOption("shared_memory_size", buf, PGC_INTERNAL, PGC_S_OVERRIDE);
+
+#if defined(MAP_HUGETLB)
+
+ /* Calculate the number of huge pages required */
+ GetHugePageSize(&hp_size, &unused);
+ hp_required = (size_b / hp_size) + 1;
+
+ sprintf(buf, "%lu", hp_required);
+ SetConfigOption("huge_pages_required", buf, PGC_INTERNAL, PGC_S_OVERRIDE);
+
+#endif
}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index a11387c5ce..1a30d635fc 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -621,6 +621,7 @@ char *pgstat_temp_directory;
char *application_name;
int shmem_size_mb;
+int huge_pages_required;
int tcp_keepalives_idle;
int tcp_keepalives_interval;
@@ -2225,6 +2226,17 @@ static struct config_int ConfigureNamesInt[] =
NULL, NULL, NULL
},
+ {
+ {"huge_pages_required", PGC_INTERNAL, RESOURCES_MEM,
+ gettext_noop("Shows the number of huge pages needed for the main shared memory area."),
+ gettext_noop("-1 indicates that the value could not be determined."),
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+ },
+ &huge_pages_required,
+ -1, -1, INT_MAX,
+ NULL, NULL, NULL
+ },
+
{
/* This is PGC_SUSET to prevent hiding from log_lock_waits. */
{"deadlock_timeout", PGC_SUSET, LOCK_MANAGEMENT,
diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h
index 059df1b72c..c44403ed6a 100644
--- a/src/include/storage/pg_shmem.h
+++ b/src/include/storage/pg_shmem.h
@@ -88,4 +88,8 @@ extern PGShmemHeader *PGSharedMemoryCreate(Size size,
extern bool PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2);
extern void PGSharedMemoryDetach(void);
+#ifdef MAP_HUGETLB
+extern void GetHugePageSize(Size *hugepagesize, int *mmap_flags);
+#endif
+
#endif /* PG_SHMEM_H */
--
2.16.6
[application/octet-stream] v6-0001-Introduce-shared_memory_size-GUC.patch (4.5K, 4-v6-0001-Introduce-shared_memory_size-GUC.patch)
download | inline diff:
From fedabb6b8fec47ba783812b3408f3e6eeb122f74 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <[email protected]>
Date: Mon, 6 Sep 2021 18:00:02 +0000
Subject: [PATCH v6 1/3] Introduce shared_memory_size GUC.
This runtime-computed GUC shows the size of the server's main
shared memory area. While this is intended to be useful for
calculating the number of huge pages required prior to startup, it
cannot be viewed via 'postgres -C' yet. This may be addressed in a
future change.
---
doc/src/sgml/config.sgml | 14 ++++++++++++++
src/backend/postmaster/postmaster.c | 7 +++++++
src/backend/storage/ipc/ipci.c | 24 ++++++++++++++++++++++++
src/backend/utils/misc/guc.c | 13 +++++++++++++
src/include/storage/ipc.h | 1 +
5 files changed, 59 insertions(+)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 2c31c35a6b..ef0e2a7746 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10275,6 +10275,20 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-shared-memory-size" xreflabel="shared_memory_size">
+ <term><varname>shared_memory_size</varname> (<type>integer</type>)
+ <indexterm>
+ <primary><varname>shared_memory_size</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Reports the size of the main shared memory area, rounded up to the
+ nearest megabyte.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-ssl-library" xreflabel="ssl_library">
<term><varname>ssl_library</varname> (<type>string</type>)
<indexterm>
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 9c2c98614a..963c03fa93 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -1026,6 +1026,13 @@ PostmasterMain(int argc, char *argv[])
*/
InitializeMaxBackends();
+ /*
+ * Now that loadable modules have had their chance to request additional
+ * shared memory, determine the value of any runtime-computed GUCs that
+ * depend on the amount of shared memory required.
+ */
+ InitializeShmemGUCs();
+
/*
* Set up shared memory and semaphores.
*/
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 64bc16fa84..614b8e92c4 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -313,3 +313,27 @@ CreateSharedMemoryAndSemaphores(void)
if (shmem_startup_hook)
shmem_startup_hook();
}
+
+/*
+ * InitializeShmemGUCs
+ *
+ * This function initializes runtime-computed GUCs related to the amount of
+ * shared memory required for the current configuration.
+ */
+void
+InitializeShmemGUCs(void)
+{
+ char buf[64];
+ Size size_b;
+ Size size_mb;
+
+ /*
+ * Calculate the shared memory size and round up to the nearest
+ * megabyte.
+ */
+ size_b = CalculateShmemSize(NULL);
+ size_mb = add_size(size_b, (1024 * 1024) - 1) / (1024 * 1024);
+
+ sprintf(buf, "%lu MB", size_mb);
+ SetConfigOption("shared_memory_size", buf, PGC_INTERNAL, PGC_S_OVERRIDE);
+}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 467b0fd6fe..a11387c5ce 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -620,6 +620,8 @@ char *pgstat_temp_directory;
char *application_name;
+int shmem_size_mb;
+
int tcp_keepalives_idle;
int tcp_keepalives_interval;
int tcp_keepalives_count;
@@ -2337,6 +2339,17 @@ static struct config_int ConfigureNamesInt[] =
NULL, NULL, NULL
},
+ {
+ {"shared_memory_size", PGC_INTERNAL, RESOURCES_MEM,
+ gettext_noop("Shows the size of the server's main shared memory area (rounded up to the nearest MB)."),
+ NULL,
+ GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_UNIT_MB
+ },
+ &shmem_size_mb,
+ 0, 0, INT_MAX,
+ NULL, NULL, NULL
+ },
+
{
{"temp_buffers", PGC_USERSET, RESOURCES_MEM,
gettext_noop("Sets the maximum number of temporary buffers used by each session."),
diff --git a/src/include/storage/ipc.h b/src/include/storage/ipc.h
index 80e191d407..7a1ebc8559 100644
--- a/src/include/storage/ipc.h
+++ b/src/include/storage/ipc.h
@@ -79,5 +79,6 @@ extern PGDLLIMPORT shmem_startup_hook_type shmem_startup_hook;
extern Size CalculateShmemSize(int *num_semaphores);
extern void CreateSharedMemoryAndSemaphores(void);
+extern void InitializeShmemGUCs(void);
#endif /* IPC_H */
--
2.16.6
view thread (108+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: Estimating HugePages Requirements?
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox