Re: [PATCH v17 0/3] Improve proc RSS accuracy

On Thu, Feb 26, 2026 at 06:12:01PM -0700, Nathan Chancellor wrote:

Hi Mathieu,

On Thu, Feb 26, 2026 at 02:38:04PM -0500, Mathieu Desnoyers wrote:

quoted

I've successfully booted a defconfig s390x next-20260226 kernel in qemu
with 1 and 4 CPUs, and within a nested s390x VM on 2 cpus.

I guess I'll really need more info about your specific .config and
command line args to help further.

On s390 cpumask_set_cpu(0, mm_cpumask(&init_mm)); in arch_mm_preinit() writes
out-of-bounds into swap_attrs[] overwriting the terminating NULL.

This seems to happen because the return value of get_rss_stat_items_size() is
larger than PERCPU_COUNTER_TREE_ITEMS_STATIC_SIZE:

PERCPU_COUNTER_TREE_ITEMS_STATIC_SIZE: 18688
get_rss_stat_items_size(): 21504

Here I stopped looking further into this. I guess you will figure out
immediately what's wrong :)