Trixie - no support for Huge_pages in latest kernel?

[byzantic]

Describe the bug

Hi - I have just upgraded to Trixie, and I'm having problems compiling a tool that I used on bookworm.

I get a warning during compile : ** Warning: madvise: MADV_HUGEPAGE: Invalid argument

This seems to be a custom warning in the code, related to huge_pages. I checked for huge_page support by running

grep "Hugepagesize:" /proc/meminfo

there's no result from this search, so I conclude there's no support for huge pages in the kernel? Is that correct? I would have thought it was usually enabled by default.

Regards Rob

Steps to reproduce the behaviour

Attempt to compile a program that requires huge page support (I was compiling nvc from https://github.com/nickg/nvc

Device (s)

Raspberry Pi 5

System

cat /etc/rpi-issue:
Raspberry Pi reference 2025-10-01
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 7dadcf1fc5ce1648ab09409ab978831690c9a955, stage4

vcgencmd version:
2025/08/27 20:01:47 
Copyright (c) 2012 Broadcom
version 000d3ca2 (release) (embedded)

uname -a
Linux carnelian 6.12.47+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux

Logs

No response

Additional context

No response

[pelwell]

Are you saying this has worked previously?

[byzantic]

The program compiled fine on bookworm about 10 months ago. But .. it's possible that version did not require huge page support. I have a query raised with the author as well, so that point should get answered.

UPDATE
The author confirmed he has been using huge page support since 2022, so this must have been present in the bookworm kernels?

In my case, this issue isn't critical - the program falls back to non-hugepage operation, and following the author's suggestion, I just commented out the warning.

But I just wondered whether there might be applications that do require it .. probably database servers or similar?

[popcornmix]

CONFIG_TRANSPARENT_HUGEPAGE_MADVISE has never been enabled on any official Pi kernel(*).
It has been considered (see #6390), but has not been merged yet.

It does offer some performance advantages for v3d driver, so could be merged if we can convince ourselves the cost/benefit ratio is worthwhile.

(*) Also note that bookworm and trixie are using exactly the same kernel package.

[byzantic]

Hmm .. I must have been mistaken, then, or (more probably) just ignored the warnings..

I'll close this, as it's not an issue that seems to affect anybody.