On Tuesday 13 February 2018 17:36:54 Ville Syrjälä wrote: > On Tue, Feb 13, 2018 at 02:38:42PM +0100, Pali Rohár wrote: > > On Tuesday 13 February 2018 15:27:26 Ville Syrjälä wrote: > > > On Tue, Feb 13, 2018 at 09:50:30AM +0100, Pali Rohár wrote: > > > > On Tuesday 06 February 2018 16:21:43 Pali Rohár wrote: > > > > > Hi! I'm periodically getting following message in dmesg on Lenovo > > > > > Thinkpad X1 Carbon 3rd generation: > > > > > > > > > > [drm] Reducing the compressed framebuffer size. This may lead to less > > > > > power savings than a non-reduced-size. Try to increase stolen memory > > > > > size if available in BIOS. > > > > > > > > > > In BIOS I already set GPU size to 512M, but this did not help. Also > > > > > update to last BIOS version did not help. > > > > > > > > > > So why this message is periodically print in dmesg? And what can I do > > > > > with this problem? > > > > > > > > > > And why cannot Linux kernel allocate itself more memory for GPU (if > > > > > BIOS > > > > > can/could do that)? Is not 512MB for GPU enough? > > > > > > > > And here is output from lspci, which clearly says that 512MB is already > > > > set for GPU: > > > > > > The PCI BAR size has nothing to do with the size of the stolen memory. > > > The BAR just provides a window into the global GTT address space of the > > > GPU. Stolen memory is a contiguous chunk of physical memory carved out > > > by the BIOS. > > > > Ok, how could I detect how much memory was stolen? > > > > In dmesg I see following lines: > > > > [ 0.000000] e820: BIOS-provided physical RAM map: > > [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable > > [ 0.000000] BIOS-e820: [mem 0x0000000000058000-0x0000000000058fff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x0000000000059000-0x000000000008bfff] usable > > [ 0.000000] BIOS-e820: [mem 0x000000000008c000-0x000000000009ffff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000ab908fff] usable > > [ 0.000000] BIOS-e820: [mem 0x00000000ab909000-0x00000000abb08fff] type > > 20 > > [ 0.000000] BIOS-e820: [mem 0x00000000abb09000-0x00000000acbfefff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x00000000acbff000-0x00000000acd7efff] ACPI > > NVS > > [ 0.000000] BIOS-e820: [mem 0x00000000acd7f000-0x00000000acdfefff] ACPI > > data > > [ 0.000000] BIOS-e820: [mem 0x00000000acdff000-0x00000000acdfffff] usable > > [ 0.000000] BIOS-e820: [mem 0x00000000f80f8000-0x00000000f80f8fff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] > > reserved > > [ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000024dffffff] usable > > > > [ 0.000000] Reserving Intel graphics memory at > > 0x00000000ae000000-0x00000000afffffff > > That's the one. Since you have a BDW the amount FBC can actually use > will be 8MiB less than what's reported here. So looks like you should > have 24MiB total, minus whatever else we end up allocating from stolen. > > Check /sys/kernel/debug/dri/0/i915_gem_stolen to see what's there. Most
$ 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? > > > > [ 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? > > > > > > > > > > $ lspci -v -s 00:02.0 > > > > 00:02.0 VGA compatible controller: Intel Corporation HD Graphics 5500 > > > > (rev 09) (prog-if 00 [VGA controller]) > > > > Subsystem: Lenovo HD Graphics 5500 > > > > Flags: bus master, fast devsel, latency 0, IRQ 46 > > > > Memory at e0000000 (64-bit, non-prefetchable) [size=16M] > > > > Memory at c0000000 (64-bit, prefetchable) [size=512M] > > > > I/O ports at 3000 [size=64] > > > > [virtual] Expansion ROM at 000c0000 [disabled] [size=128K] > > > > Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- > > > > Capabilities: [d0] Power Management version 2 > > > > Capabilities: [a4] PCI Advanced Features > > > > Kernel driver in use: i915 > > > > Kernel modules: i915 > > > > > > > > -- > > > > Pali Rohár > > > > pali.ro...@gmail.com > > > > _______________________________________________ > > > > dri-devel mailing list > > > > dri-devel@lists.freedesktop.org > > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > > > > -- > > Pali Rohár > > pali.ro...@gmail.com > -- Pali Rohár pali.ro...@gmail.com _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
