Doc: prefer sysctl to /proc/sys in docs and comments.

sysctl is more portable than Linux's /proc/sys file tree, and
often easier to use too.  That's why most of our docs refer to
sysctl when talking about how to adjust kernel parameters.
Bring the few stragglers into line.

Discussion: https://postgr.es/m/361175.1661187463@sss.pgh.pa.us

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 963b18ed850d459c83af4e99e018ddeea07df7b9..5d0b32121d980ea363b9be3f2e0bf543864e4859 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1258,11 +1258,12 @@ default:\
     <itemizedlist>
      <listitem>
       <para>
-      On <productname>Linux</productname>
-      <filename>/proc/sys/fs/file-max</filename> determines the
-      maximum number of open files that the kernel will support.  It can
-      be changed by writing a different number into the file or by
-      adding an assignment in <filename>/etc/sysctl.conf</filename>.
+      On <productname>Linux</productname> the kernel parameter
+      <varname>fs.file-max</varname> determines the maximum number of open
+      files that the kernel will support.  It can be changed with
+      <literal>sysctl -w fs.file-max=<replaceable>N</replaceable></literal>.
+      To make the setting persist across reboots, add an assignment
+      in <filename>/etc/sysctl.conf</filename>.
       The maximum limit of files per process is fixed at the time the
       kernel is compiled; see
       <filename>/usr/src/linux/Documentation/proc.txt</filename> for

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 8a038d1b2aee11a5389626b5d83bd45b6e841860..1664fcee2a70fbd9a53ce7796c8aa77ae2a48047 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4891,7 +4891,7 @@ SubPostmasterMain(int argc, char *argv[])
         * If testing EXEC_BACKEND on Linux, you should run this as root before
         * starting the postmaster:
         *
-        * echo 0 >/proc/sys/kernel/randomize_va_space
+        * sysctl -w kernel.randomize_va_space=0
         *
         * This prevents using randomized stack and code addresses that cause the
         * child process's memory map to be different from the parent's, making it