On Thu, Mar 14, 2024 at 08:56:59AM +0000, Christophe Leroy wrote:

Le 13/03/2024 à 22:47, peterx@redhat.com a écrit :

quoted

From: Peter Xu <peterx@redhat.com>

This API is not used anymore, drop it for the whole tree.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
  arch/arm/mm/Makefile                          |  1 -
  arch/arm/mm/hugetlbpage.c                     | 29 -------------------
  arch/arm64/mm/hugetlbpage.c                   | 10 -------
  arch/loongarch/mm/hugetlbpage.c               | 10 -------
  arch/mips/include/asm/pgtable-32.h            |  2 +-
  arch/mips/include/asm/pgtable-64.h            |  2 +-
  arch/mips/mm/hugetlbpage.c                    | 10 -------
  arch/parisc/mm/hugetlbpage.c                  | 11 -------
  .../include/asm/book3s/64/pgtable-4k.h        | 10 -------
  .../include/asm/book3s/64/pgtable-64k.h       | 25 ----------------
  arch/powerpc/include/asm/nohash/pgtable.h     | 10 -------
  arch/riscv/mm/hugetlbpage.c                   | 10 -------
  arch/s390/mm/hugetlbpage.c                    | 10 -------
  arch/sh/mm/hugetlbpage.c                      | 10 -------
  arch/sparc/mm/hugetlbpage.c                   | 10 -------
  arch/x86/mm/hugetlbpage.c                     | 16 ----------
  include/linux/hugetlb.h                       | 24 ---------------
  17 files changed, 2 insertions(+), 198 deletions(-)
  delete mode 100644 arch/arm/mm/hugetlbpage.c

quoted

diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
index 0e196650f4f4..92b7591aac2a 100644
--- a/arch/mips/include/asm/pgtable-32.h
+++ b/arch/mips/include/asm/pgtable-32.h

@@ -129,7 +129,7 @@ static inline int pmd_none(pmd_t pmd)
  static inline int pmd_bad(pmd_t pmd)
  {
  #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
-	/* pmd_huge(pmd) but inline */
+	/* pmd_leaf(pmd) but inline */

Shouldn't this comment have been changed in patch 11 ?

IMHO it's fine to be here, as this is the patch to finally drop _huge().
Patch 11 only converts the callers to use _leaf()s.  So this comment is
still valid until this patch, because this patch removes that definition.

quoted

  	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))

Unlike pmd_huge() which is an outline function, pmd_leaf() is a macro so 
it could be used here instead of open coping.

I worry it will break things as pmd_leaf() can sometimes be defined after
arch *pgtable.h headers.  So I avoided touching it except what I think I'm
confident.  I had a feeling it's inlined just because of a similar reason
for the old _huge().

quoted

  		return 0;
  #endif

diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index 20ca48c1b606..7c28510b3768 100644
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h

@@ -245,7 +245,7 @@ static inline int pmd_none(pmd_t pmd)
  static inline int pmd_bad(pmd_t pmd)
  {
  #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
-	/* pmd_huge(pmd) but inline */
+	/* pmd_leaf(pmd) but inline */

Same

quoted

  	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))

Same

quoted

  		return 0;
  #endif

quoted

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h
index 2fce3498b000..579a7153857f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h

@@ -4,31 +4,6 @@
  
  #ifndef __ASSEMBLY__
  #ifdef CONFIG_HUGETLB_PAGE
-/*
- * We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
- * 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
- *
- * Defined in such a way that we can optimize away code block at build time
- * if CONFIG_HUGETLB_PAGE=n.
- *
- * returns true for pmd migration entries, THP, devmap, hugetlb
- * But compile time dependent on CONFIG_HUGETLB_PAGE
- */

Should we keep this comment somewhere for documentation ?

The 2nd/3rd paragraphs are definitely obsolete, so should be dropped.

OTOH, I'm not sure how much that will help if e.g. I move that over to
pmd_leaf(): a check over cpu_to_be64(_PAGE_PTE) is an implementation as
simple as it could be to explain itself with even no comment to me..

I also don't fully digest why that 1st paragraph discusses PGD entries: for
example, there's no pgd_huge() defined.  It may not mean that the comment
is wrong, perhaps it means that I may lack some knowledge around this area
on Power..

Would you suggest how I should move paragraph 1 (and help to explain what
it is describing)?  Or maybe we can provide a separate patch for Power's
huge page sizes but posted separately (and very possibly I'm not the best
candidate then..).

quoted

-static inline int pmd_huge(pmd_t pmd)
-{
-	/*
-	 * leaf pte for huge page
-	 */
-	return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
-}
-
-static inline int pud_huge(pud_t pud)
-{
-	/*
-	 * leaf pte for huge page
-	 */
-	return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
-}
  
  /*
   * With 64k page size, we have hugepage ptes in the pgd and pmd entries. We don't

-- 
Peter Xu