linux-kernel - Re: [PATCH] Add possibility to set /dev/tty number

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Message-ID: <20160106135439.52231ba2@lxorguk.ukuu.org.uk>
Date:	Wed, 6 Jan 2016 13:54:39 +0000
From:	One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>
To:	"Austin S. Hemmelgarn" <ahferroin7@...il.com>
Cc:	Greg KH <gregkh@...uxfoundation.org>,
	Pierre Paul MINGOT <mingot.pierre@...il.com>, jslaby@...e.cz,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Add possibility to set /dev/tty number

> In fact, there already appears to be some degree of allocation on demand 
> for VT's (otherwise deallocvt has no point), just not for everything 
> associated with the VT.  I'd be willing to bet that almost everything 
> that reasonably can be dynamically allocated already is, there is a bare 
> minimum required for even a virtual device after all.

If there is 1.6K overhead per vt coming from somewhere (given we only
preallocate 1 VT) then either

- There is stuff not being dynamically allocated (which you can find and
  fix)

- Your userspace is triggering those dynamic allocations

There is no magic thing that requires 1.6K of kernel data per console.

Alan
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