Rpm-ostree kargs entries seem to not be working for transparent hugepage defrag

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1

So I have a fun issue, performance on iGPUs benefit significantly from using transparent hugepages (when you have sufficient RAM). I have managed to enable transparent hugepages themselves however the defrag option isn’t working like it did on my previous debian install.

On Debian I only needed to pass the following for defrag to be set to defer (rather than madvise)

GRUB_CMDLINE_LINUX_DEFAULT="transparent_hugepage=always defrag=defer"

On Fedora Silverblue, latest release and fully up to date, I have tried using kargs --editor with the following options added

transparent_hugepage=always defrag=defer

and

transparent_hugepage=always transparent_hugepage=defrag=defer

Despite this both cases set the defrag option to madvise. How would I tell if this is simply failing to set the kernel parametre to do it or if some other process is setting it to a different option?

3

Could it be that defrag is not a valid kernel parameter, or that the syntax is not correct?

I have found that transparent_hugepage is a valid one, and from your post it seems to be working after being added by the rpm-ostree kargs command, but not defrag (or transparent_hugepage=defrag).