On Mon, Jun 01, 2020 at 05:26:16AM -0700, Paul Goyette wrote:
You can strip out a lot more modules and still have a functioning
system. Mostly you can remove all the device drivers for devices
that don't exist, but there are other things, too.
Another small module question: when running a -current kernel with 9.0
userland, the compat_90 module is loaded, as I believe it should given the
MODULAR_DEFAULT_AUTOLOAD option. Due to module_start_unload_thread(9), it is
also over and over again unloaded:
$ modstat > d && sleep 3 && modstat > dd && diff -u d dd
--- d 2020-06-02 08:19:44.893168878 +0300
+++ dd 2020-06-02 08:19:47.915516801 +0300
@@ -26,6 +26,7 @@
cir driver builtin - 1 - ir
clockctl driver builtin - 0 - -
coda vfs builtin - 0 - vcoda
+compat_90 exec filesys a 0 - -
compat_util misc builtin - 0 - -
coredump misc builtin - 0 - -
coretemp driver boot - 0 - sysmon_envsys
This kind of constant unload/load trashing does not seem optimal. I would
expect there to be also a performance impact.
So can I control module unloading at runtime? That is, I want:
$ sysctl kern.module.autoload
kern.module.autoload = 1
But there is no "kern.module.autounload", which I would want to be 0.