Video is slow

[Marko Vojinovic]

On Sun, 25 Aug 2013 22:12:34 -0700
Joe Zeff <joe at zeff.us> wrote:
> On 08/25/2013 09:21 PM, Marko Vojinovic wrote:
> > While I respect Joe Zeff as a reputable member of this list, those
> > instructions on fedoraforum are a total piece of crap. I don't know
> > who wrote those instructions, but overengineering a solution for a
> > common problem is a always a Recipe For Disaster(tm).
> 
> Don't forget that some of them were written for newcomers who may or
> may not know if their card's even supported.  Once you have rpmfusion
> set up, all you really need to do is have yum install kmod-nvidia,
> the xorg files that it needs, run dracut and reboot.  (Using akmod,
> of course, gives you a slightly different set of files.)  Most of the
> complexity comes from the author having to take all sorts of
> possibilities into account; as a user, you just pick the set of
> instructions that matches you card.  I've never yet had them fail,
> but I have read posts on that forum where others have; usually,
> they've either picked the wrong set of files to install or didn't
> follow the instructions correctly.  YMMV, and obviously does, but
> everything I've seen, both personally and through threads on
> fedoraforum lead me to believe that they're about as good a set of
> instructions as you're likely to find.
> 
> BTW, Marco, do you have a link to a set of instructions you find
> better? If so, I'd be interested in looking at them and possibly
> pointing others to them instead in the future.

I don't have a link to point you to, aside from my first answer to
Roger above (that link can be found in the list archives).

But it literally boils down to three steps:

(1) activate rpmfusion,
(2) yum install kmod-nvidia,
(3) reboot the machine.

Feel free to substitute akmod in place of kmod if you wish.

With those in mind, if you want to write down an instruction manual, I
can say only this:

* Give the user a link to rpmfusion website, and let him figure out how
  to activate it, if he didn't already. Giving him some ugly rpm
  --nogpgcheck install http://blabla stuff is a bad idea on several
  grounds, but most importantly the rpmfusion website is the
  authoritative reference on how to activate it, and there is no need
  to reinvent instructions that already exist.

* The yum installation of (a)kmod-nvidia will pull in any dependencies
  it needs, including xorg libs, -header and -devel packages, even gcc
  if necessary. There is no need to specify any of those manually.

* The nouveau is being disabled and dracut is being run as part of the
  post-install scripts for kmod-nvidia. Neither of those should be done
  manually. Especially not by a newbie.

* Any of the remaining stuff about PAE kernels, selinux policies, grub
  tweaking and manually blacklisting nouveau should be frown upon. Not
  only that those things are not necessary for the installation of the
  driver, but moreover they can be downright dangerous if handled by
  a newbie.

There is one more thing regarding the dracut stuff --- aside from the
fact that it is completely unnecessary since kmod-nvidia will already
do it by itself, doing it like this:

mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname
-r)-nouveau.img
dracut /boot/initramfs-$(uname -r).img $(uname -r)

literally means asking for trouble. The mv command is almost
instantaneous, while the dracut command will take a good several
minutes to complete. In that sense, during the period after you have
renamed a valid initramfs file to some name that grub will not know to
look for, and before dracut has completed the new file, you do not have
a bootable machine, since there is no initramfs file for grub to
fallback on if something goes wrong. What will happen if a power surge
shuts down your computer in the middle of dracut run? Doing a mv before
dracut is a recipe to paint yourself into a corner.

What should be done instead is to first invoke dracut with a different
file name:

dracut /boot/mynewramfs-$(uname -r).img $(uname -r)

so that you don't touch the original file while this is being done.
Then, you want to *copy* the current initramfs into a backup:

cp /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r)-nouveau.img

Finally, you want to move the new file into the place of the old one:

mv /boot/mynewramfs-$(uname -r).img /boot/initramfs-$(uname -r)

Since the file already exists, and since the root alias for mv is
interactive, it will ask you do you really want to overwrite the old
file. Answering yes will be fast, painless and a proof that you didn't
make any typos in the above commands.

During the whole procedure, if the machine loses power, it has a valid
initramfs file to fallback on automatically.

Again, all that said, yum install kmod-nvidia will will do all that
automatically, and there is really no reason to invoke dracut manually
in the first place. You just risk to fsck up something, like it just
happened to Roger.

HTH, :-)
Marko