Re: Subject: Regression: CONFIG_ASYNC_KERNEL_PGTABLE_FREE causes memory exhaustion and stalls on busy Cascade Lake server (6.18.7 only)

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 29/01/2026 à 07:10, Robert Dinse a écrit :
> 
> 
> Reverting to 6.18.6 immediately restores the previous stable behavior.
> 
> Attempt to disable CONFIG_ASYNC_KERNEL_PGTABLE_FREE
> ---------------------------------------------------
> I attempted to disable the new async kernel page table freeing feature:
> 
> - The symbol `CONFIG_ASYNC_KERNEL_PGTABLE_FREE` appears in `.config`
> - However, it does not appear in xconfig or other configuration frontends
> - Manually editing `.config` to disable it works only until the next 
> `make`:
>    - As soon as I re-run the build, the option is silently re-enabled
> - I tried to chase the Kconfig dependencies, but the chain was too 
> convoluted; it appears to be effectively non-user-selectable and forced 
> on by default for my architecture.
> 
>  From an operator perspective, this feature as currently implemented is 
> not workable on a busy machine like this, and the inability to disable 
> it makes it difficult to bisect or run with a known-good configuration.
> 

Try reverting commit 9f0a7ab700f8 ("iommu/sva: invalidate stale IOTLB 
entries for kernel address space") ?

Christophe