Re: tty_[un]register_devfs putting 3K structures on the stack

[Theodore Y. Ts'o]

   Date: 	Fri, 06 Oct 2000 12:01:34 -0500
   From: Jeff Dike <[e-mail]>

   tty_register_devfs and tty_unregister_devfs both declare "struct tty_struct" locals.

   According to gdb:

   (gdb) p sizeof(struct tty_struct)
   $20 = 3084

   This eats up most of a 4K page, and on UML this is causing the stack to flow off the page for some people.

   Is it possible to make that tty_struct static or kmalloc it or
   something?

And it's allocating a tty_struct for a really dumb reason, too.  It's
just using it so it cna call tty_name.

Just replace the call to tty_name with something like this:

	sprintf(buf, driver->name, idx + driver->name_base)

and make the obvious change to avoid using tty.device, and you can avoid
need to allocate a tty_struct altogether.

						- Ted