Adjust documentation for configuring Linux huge pages.

The present wording about viewing shared_memory_size_in_huge_pages
seems to suggest that the parameter cannot be viewed after startup
at all, whereas the intent is to make it clear that you can't use
"postgres -C" to view this parameter while the server is running.
This commit rephrases this section to remove the ambiguity.

Author: Seino Yuki
Reviewed-by: Michael Paquier, David G. Johnston, Fujii Masao
Discussion: https://postgr.es/m/420584fd274f9ec4f337da55ffb3b790%40oss.nttdata.com
Backpatch-through: 15

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 2c4d5ef640d5708cb7e06b3a4137a85193dd00c5..a47fa67b38007cb44a4c87227a7ac9390ae5d15b 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1429,11 +1429,10 @@ export PG_OOM_ADJUST_VALUE=0
     with CONFIG_HUGETLBFS=y and
     CONFIG_HUGETLB_PAGE=y. You will also have to configure
     the operating system to provide enough huge pages of the desired size.
-    To determine the number of huge pages needed, use the
-    postgres command to see the value of
-    .  Note that the
-    server must be shut down to view this runtime-computed parameter.
-    This might look like:
+    The runtime-computed parameter
+     reports the number
+    of huge pages required.  This parameter can be viewed before starting the
+    server with a postgres command like:
 
 $ postgres -D $PGDATA -C shared_memory_size_in_huge_pages
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