On Wed, 2021-10-27 at 16:17 +0200, David Hildenbrand wrote:

On 27.10.21 15:41, Joakim Tjernlund wrote:

quoted

On Wed, 2021-10-27 at 14:35 +0100, Matthew Wilcox wrote:

quoted

On Wed, Oct 27, 2021 at 12:48:13PM +0000, Joakim Tjernlund wrote:

quoted

Linux version 5.11.0
Memory: 24052K/32768K available (3520K kernel code, 684K rwdata, 548K rodata, 320K init, 245K bss, 8716K reserved, 0K cma-reserved)

Versus:

Linux version 5.10.75
Memory: 11836K/32768K available (3518K kernel code, 684K rwdata, 540K rodata, 320K init, 244K bss, 20932K reserved, 0K cma-reserved)

... you're complaining that we reduced the amount of reserved ram?
You know that 5.11.0 is more recent than 5.10.75, right?

Sort of :)
No kernel I have used earlier has reserved so much RAM in the past so I figure that
20 MB in 5.10 is a regression.

Reason for using 5.10 is that it is an LTS kernel that will be around for quite a while.

Do you have any comparison against older v5.10 kernels -- IOW, is it a
regression within the LTS kernels or has it "simply been optimized"
starting with v5.11 ?

I don't have anything older, we just got started with this project and tried these 2 kernels.
Previous system was ppc with 4.19.x and that is even lower than the two 5.x kernels.

(a lot of things count as reserved, including the initial ramdisk until
eventually freed, but I assume your setup really just exchanges the kernel)

Sure, but this just booting kernel without any disk/fs. The difference should not be that
extrem in 5.10 vs 5.11, should they?