On 07/01/2025 13:31, Qi Zheng wrote:

On 2025/1/7 19:58, Kevin Brodsky wrote:

quoted

On 07/01/2025 11:51, Qi Zheng wrote:

quoted

[...]

Author: Qi Zheng [off-list ref]
Date:   Fri Dec 13 17:13:48 2024 +0800

     mm: pgtable: completely move pagetable_dtor() to generic
tlb_remove_table()

     For the generic tlb_remove_table(), it is implemented in the
following two
     forms:

     1) CONFIG_MMU_GATHER_TABLE_FREE is enabled

     tlb_remove_table
     --> generic __tlb_remove_table()

     2) CONFIG_MMU_GATHER_TABLE_FREE is disabled

     tlb_remove_table
     --> tlb_remove_page

     For case 1), the pagetable_dtor() has already been moved to
generic
     __tlb_remove_table().

     For case 2), now only arm will call
tlb_remove_table()/tlb_remove_ptdesc()
     when CONFIG_MMU_GATHER_TABLE_FREE is disabled. Let's move
pagetable_dtor()
     completely to generic tlb_remove_table(), so that the
architectures can
     follow more easily.

     Signed-off-by: Qi Zheng [off-list ref]

I missed your Suggested-by, will add it in v5.

Ah yes thanks!

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diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index b8eebdb598631..ea4fbe7b17f6f 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h

@@ -34,10 +34,6 @@ __pte_free_tlb(struct mmu_gather *tlb, pgtable_t

pte, unsigned long addr)
  {
         struct ptdesc *ptdesc = page_ptdesc(pte);

-#ifndef CONFIG_MMU_GATHER_TABLE_FREE
-       pagetable_dtor(ptdesc);
-#endif

I guess this hunk will disappear since this call isn't present to start
with.

Yes, I plan to add this in the patch #8, and remove it in this patch.

Right I guess this is required to keep patch 8 self-contained, makes sense.

quoted

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-
  #ifndef CONFIG_ARM_LPAE
         /*
          * With the classic ARM MMU, a pte page has two
corresponding pmd

diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 69de47c7ef3c5..53ae7748f555b 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h

@@ -220,14 +220,20 @@ static inline void __tlb_remove_table(void

*table)

  extern void tlb_remove_table(struct mmu_gather *tlb, void *table);

-#else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */
+#else /* !CONFIG_MMU_GATHER_TABLE_FREE */

Good catch!

quoted

+static inline void tlb_remove_page(struct mmu_gather *tlb, struct
page *page);

Nit: might be better to move the declaration up, e.g. above #ifdef
CONFIG_MMU_GATHER_TABLE_FREE.

Now only the tlb_remove_table() below calls it, maybe it's better to
keep the impact to minimum?

I feel it might be better to make the declaration unconditional, but
this is really a detail, I don't mind either way.

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  /*
   * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have
page based
   * page directories and we can use the normal page batching to free
them.
   */
-#define tlb_remove_table(tlb, page) tlb_remove_page((tlb), (page))
+static inline void tlb_remove_table(struct mmu_gather *tlb, void
*table)
+{
+       struct page *page = (struct page *)table;

+       pagetable_dtor(page_ptdesc(page));
+       tlb_remove_page(tlb, page);
+}
  #endif /* CONFIG_MMU_GATHER_TABLE_FREE */

  #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE

Looks good to me otherwise.

I will add your Reviewed-by to all patches (except yours) in v5, can
I also add it to this new added patch? (if we agree with the discussion
above) ;)

Yes please do, thanks!

- Kevin