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Re: Does wscons use compat syscalls to switch sessions

On Sun, Oct 18, 2015 at 11:03:37 +0800, Paul Goyette wrote:

> I just noticed that when switching console sessions from my X display
> (on ttyE4) to the console session (on ttyE0), the system auto-loads the
> "compat" kernel module.
> Is this expected?  normal?  Shouldn't all "current" production code be
> using "current" syscalls and/or ioctls?

This might be (haven't looked) the same problem I complained about
some time ago on tech-kern:

On Sun, Dec 15, 2013 at 15:35:01 +0400, Valery Ushakov wrote:

> Date: Sun, 15 Dec 2013 15:35:01 +0400
> From: Valery Ushakov <>
> Subject: Compat module auto-bounce
> To:
> ttioctl() in sys/tty.c ends with doing
>     (void)module_autoload("compat", MODULE_CLASS_ANY);
> for ioctls that it doesn't know about.  This causes compat module to
> auto-bounce in and out a lot.  Note that this happens even for
> up-to-date userland that doesn't need compat code.  E.g. ttyname(3)
> uses TIOCPTSNAME which ttioctl() doesn't handle.  Running vi on
> console seems to cause compat.mod to be autoloaded twice.
> This seems rather wasteful.


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