lkml.org 
[lkml]   [2018]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Thinkpad X1 Carbon 3rd - Reducing the compressed framebuffer size
On Tuesday 13 February 2018 18:12:21 Ville Syrjälä wrote:
> On Tue, Feb 13, 2018 at 05:04:37PM +0100, Pali Rohár wrote:
> > $ cat /sys/kernel/debug/dri/0/i915_gem_stolen
> > Stolen:
> > ffff8b55bf17e080: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00083000, size: 00004000, type: 0) (stolen: 00001000)
> > ffff8b55c2693040: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 02b9f000, size: 00004000, type: 0) (stolen: 00005000)
> > ffff8b55bf9a7300: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0f6b4000, size: 00004000, type: 0) (stolen: 00009000)
> > ffff8b55a6161040: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0937f000, size: 00004000, type: 0) (stolen: 0000d000)
> > ffff8b5563e0dac0: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0f714000, size: 00004000, type: 0) (stolen: 00019000)
> > ffff8b55bf17e800: g 4KiB 41 00 [ 0 0 0 0 ] 0 LLC (pinned x 1) (ggtt offset: ffffe000, size: 00001000, type: 0) (stolen: 0012c000)
> > ffff8b55bf02d540: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00141000, size: 00004000, type: 0) (stolen: 0012d000)
> > ffff8b55c2989340: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00148000, size: 00004000, type: 0) (stolen: 00131000)
> > ffff8b55c29890c0: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 0014f000, size: 00004000, type: 0) (stolen: 00135000)
> > ffff8b55c2989840: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00156000, size: 00004000, type: 0) (stolen: 00139000)
> > ffff8b55bf02da40: p g 14400KiB 77 00 [ 0 0 0 0 ] 0 uncached dirty (name: 1) (pinned x 1) (display) (ggtt offset: 0015a000, size: 00e10000, type: 0) (stolen: 0013d000) (p mappable)
> > ffff8b556dfba780: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0ad2a000, size: 00004000, type: 0) (stolen: 01655000)
> >
> > > likely you'll have the fbdev framebuffer taking up a sizeable chunk.
> >
> > Seems 14MB.
> >
> > > You could get some back by reducing fbdev depth to 16bpp, or even 8bpp,
> > > but I'm not convinced the fbdev gamma LUT stuff really works currently
> > > so you might end up with bogus colors in your vts with that.
> >
> > Ok, I could try it. Via fbset tool?
>
> Kernel command line. We don't allow resizing the fbdev fb once it's
> created.

Ok, will try.

> >
> > > >
> > > > [ 0.000000] Memory: 7972840K/8282704K available (6196K kernel code, 1159K rwdata, 2848K rodata, 1408K init, 688K bss, 309864K reserved, 0K cma-reserved)
> > > >
> > > > > The BIOS may or may not provide a knob to change the size
> > > > > of the stolen memory.
> > > >
> > > > In BIOS Setup screen I have option to choose GPU memory and I set it to
> > > > max 512MB. So this is not the right option...
> > > >
> > > > And why cannot kernel use some continuous check of RAM itself?
> > >
> > > Because the hardware won't allow it.
> >
> > So it can be done only once after reboot? Or only prior to booting kernel?
>
> Never.

Never? Now I'm lost. Why then dmesg message instruct user to try set up
it in BIOS if you say it is never possible?

--
Pali Rohár
pali.rohar@gmail.com
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2018-02-13 18:45    [W:0.059 / U:3.892 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site