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 66dacaeb4222b47ecbac7887566c296bcc59c77e..d0632f2d08afa09806d46434996332711f8b01a0 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1302,11 +1302,12 @@ 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 661b2d037f2ad0126c58fe9719cdc8e5b7e2df4b..ddf553b85b90e9f2235d97421a89be466f50581e 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4876,7 +4876,7 @@ 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