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 5b2ab083b66f5bf4d542152ce78dbdec909eeb12..7fac9617ce75ec86cf8d95fef855d7a82969dfee 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1355,11 +1355,12 @@ 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 4f153ae1c61f7cb9fc4fc67e4cff0de1fb7c383b..a8b3f5000c2a3d0e6e3ab33dcc1a71ebb183b0b0 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4908,7 +4908,7 @@ 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