On Fri, Jun 07, 2024 at 06:14:28PM +0300, Kirill A. Shutemov wrote: > I was able to address this issue by switching cpa_lock to a mutex. > However, this solution will only work if the callers for set_memory > interfaces are not called from an atomic context. I need to verify if > this is the case. Dunno, I'd be nervous about this. Althouth from looking at ad5ca55f6bdb ("x86, cpa: srlz cpa(), global flush tlb after splitting big page and before doing cpa") I don't see how "So that we don't allow any other cpu" can't be done with a mutex. Perhaps the set_memory* interfaces should be usable in as many contexts as possible. Have you run this with lockdep enabled? > - The function __flush_tlb_all() in kernel_(un)map_pages_in_pgd() must be > called with preemption disabled. Once again, I am unsure why this has > not caused issues in the EFI case. It could be because EFI does all that setup on the BSP only before the others have arrived but I don't remember anymore... It is more than a decade ago when I did this... Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette