Dear Linux folks,
On an Asus F2A85-M PRO with two 2 GB RAM modules installed, and an APU
device, building Linux with `ARCH=i386` and `CONFIG_HIGHMEM4G=y` only 3
GB seem to be detected: 2.2 GB according to `free -h` plus the 768 MB
for APU graphics memory).
> [ 0.065059] Memory: 2285148K/2324512K available (11785K kernel code, 892K rwdata, 2748K rodata, 668K init, 544K bss, 39364K reserved, 0K cma-reserved, 1423796K highmem)
> [ 0.402082] calling populate_rootfs+0x0/0xa1 @ 1
> $ free -h
> total used free shared buff/cache available
> Mem: 2,2Gi 72Mi 2,0Gi 13Mi 130Mi 2,0Gi
> Swap: 0B 0B 0B
With `CONFIG_HIGHMEM64G=y` the whole 4 GB are used (3.1 GB + 768 MB for
APU graphics memory).
> [ 0.121036] Memory: 3229952K/3356700K available (10301K kernel code, 821K rwdata, 2700K rodata, 708K init, 540K bss, 126748K reserved, 0K cma-reserved, 2449840K highmem)
> [ 0.450668] calling populate_rootfs+0x0/0xa1 @ 1
The Kconfig help text for `HIGHMEM4G` says:
> Select this if you have a 32-bit processor and between 1 and 4 │
> gigabytes of physical RAM.
As I only have 4 GB, I chose that to save 50 ms (maybe only due to less
memory detected), and thought non-PAE kernels can use 4 GB of memory.
Kind regards,
Paul