Re: [PATCH v1 4/4] mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather

[Nadav Amit <nadav.amit@gmail.com>]

> On 7 Dec 2025, at 14:15, Nadav Amit <nadav.amit@gmail.com> wrote:
> 
> 
>> On 5 Dec 2025, at 23:35, David Hildenbrand (Red Hat) <david@kernel.org> wrote:
>> 
>> @@ -400,6 +411,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb)
>> 
> 
> @@ -400,6 +411,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb)
> 	tlb->cleared_pmds = 0;
> 	tlb->cleared_puds = 0;
> 	tlb->cleared_p4ds = 0;
> +	tlb->unshared_tables = 0;
> 	/*
> 	 * Do not reset mmu_gather::vma_* fields here, we do not
> 	 * call into tlb_start_vma() again to set them if there is an
> 
> I understand you don’t want to initialize fully_unshared_tables here, but
> tlb_gather_mmu() needs to happen somewhere. So you probably want it to
> take place in tlb_gather_mmu(), no?

To clarify my messed up response: the code needs to initialize fully_unshared_tables
somewhere during tlb_gather_mmu() invocation.