Re: [PATCH v4 05/12] mm: enable MMU_GATHER_RCU_TABLE_FREE for arc, microblaze, xtensa

[sashiko-bot@kernel.org]

> Each of these architectures directly free page tables without routing these
> changes through tlb_remove_ptdesc().
> 
> The use of tlb_remove_ptdesc() is required for
> CONFIG_MMU_GATHER_RCU_TABLE_FREE to correctly free page tables under RCU,
> so simply update these architectures to use these functions.
> 
> Since none of the architectures share page tables or do anything unusual,
> nothing complicated is required here.
> 
> Therefore this is simply a mechanical change - convert __pud_free_tlb(),
> __pmd_free_tlb() and __pte_free_tlb() to use tlb_remove_ptdesc() as
> required.
> 
> At the point this is in place, all mmu_gather page table freeing is
> performed under RCU, and thus MMU_GATHER_RCU_TABLE_FREE is selected for
> each architecture.
> 
> Note that CONFIG_MMU_GATHER_RCU_TABLE_FREE is dependent on CONFIG_MMU for
> xtensa to reflect the fact that nommu does not implement page table
> gathering.
> 
> This forms part of an overall effort to switch every architecture to this
> mode.
> 
> Acked-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260922-rcu-pagetable-freeing-v4-0-fe1ad1f1e303@kernel.org?part=5