SOLVED: UEFI says 8gb memory but Amahi says 6gb - huh?

[astinusofmetate]

I installed F23/Amahi using 1 module of 4gb memory. I just added a second spare module I had on hand to upgrade it to 8gb. UEFI for the motherboard recognizes it correctly as an additional 4gb for a total of 8gb (8184mb), but for some reason the OS only sees 6gb (6914mb) total.

Do I need to enable/change some setting?

[bigfoot65]

Do I need to enable/change some setting?

There should be nothing else required. Have you checked the internet for similar issues?

[astinusofmetate]

Thanks for the sanity check. This is an AMD based setup using a combined CPU+GPU processor that shares system memory for both functions. (i.e. AMD APU on A88X chipset)

I dug around a bit just now and it looks to me like this is normal for a shared memory resource(?). I ran this command at the prompt to corroborate what I found:

Code: Select all

dmesg | grep VRAM

which returned this:

[ 1.633246] radeon 0000:00:01.0: VRAM: 1024M 0x0000000000000000 - 0x000000003FFFFFFF (1024M used)
[ 1.633249] [drm] Detected VRAM RAM=1024M, BAR=256M
[ 1.633389] [drm] radeon: 1024M of VRAM memory ready

Then

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dmesg | grep Memory

returned this:

[ 0.000000] Memory: 6849856K/7276616K available (8211K kernel code, 1416K rwdata, 3340K rodata, 1604K init, 1520K bss, 426760K reserved, 0K cma-reserved)
[ 0.331252] x86/mm: Memory block size: 128MB

The numbers look like they mostly add up, and I'm guessing that with only 4gb before, the system borrowed less system memory.

Assuming that to be the case, I think I'm used to how Windows reports memory in that it will report all 8gb and I guess Linux is only telling me the "total" availability after video allocation?

Is that sound logic?

[bigfoot65]

That makes sense. Shared memory cannot be used by OS. Windows would reflect the same likely.

Recommend you set the shared graphics memory to the least amount in the BIOS. Since the server is headless, it doesn't need much. That will likely leave you more for the OS.

I presume we can consider this resolved.

[astinusofmetate]

Agreed. Any further issues related to this topic I think are beyond the scope of using Amahi.