Re: [PATCH v6 12/14] sparc/mm: replace batch->active with is_lazy_mmu_mode_active()

Andreas Larsson
2026-01-14T07:21:17Z

On 2025-12-15 16:03, Kevin Brodsky wrote:
> A per-CPU batch struct is activated when entering lazy MMU mode; its
> lifetime is the same as the lazy MMU section (it is deactivated when
> leaving the mode). Preemption is disabled in that interval to ensure
> that the per-CPU reference remains valid.
>
> The generic lazy_mmu layer now tracks whether a task is in lazy MMU
> mode. We can therefore use the generic helper
> is_lazy_mmu_mode_active() to tell whether a batch struct is active
> instead of tracking it explicitly.
>
> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
> ---
> arch/sparc/include/asm/tlbflush_64.h | 1 -
> arch/sparc/mm/tlb.c | 9 +--------
> 2 files changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/arch/sparc/include/asm/tlbflush_64.h b/arch/sparc/include/asm/tlbflush_64.h
> index 4e1036728e2f..6133306ba59a 100644
> --- a/arch/sparc/include/asm/tlbflush_64.h
> +++ b/arch/sparc/include/asm/tlbflush_64.h
> @@ -12,7 +12,6 @@ struct tlb_batch {
> unsigned int hugepage_shift;
> struct mm_struct *mm;
> unsigned long tlb_nr;
> - unsigned long active;
> unsigned long vaddrs[TLB_BATCH_NR];
> };
>
> diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
> index 7b5dfcdb1243..3a852071d260 100644
> --- a/arch/sparc/mm/tlb.c
> +++ b/arch/sparc/mm/tlb.c
> @@ -52,11 +52,7 @@ void flush_tlb_pending(void)
>
> void arch_enter_lazy_mmu_mode(void)
> {
> - struct tlb_batch *tb;
> -
> preempt_disable();
> - tb = this_cpu_ptr(&tlb_batch);
> - tb->active = 1;
> }
>
> void arch_flush_lazy_mmu_mode(void)
> @@ -69,10 +65,7 @@ void arch_flush_lazy_mmu_mode(void)
>
> void arch_leave_lazy_mmu_mode(void)
> {
> - struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
> -
> arch_flush_lazy_mmu_mode();
> - tb->active = 0;
> preempt_enable();
> }
>
> @@ -93,7 +86,7 @@ static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
> nr = 0;
> }
>
> - if (!tb->active) {
> + if (!is_lazy_mmu_mode_active()) {
> flush_tsb_user_page(mm, vaddr, hugepage_shift);
> global_flush_tlb_page(mm, vaddr);
> goto out;

Acked-by: Andreas Larsson <andreas@gaisler.com>

Cheers,
Andreas