[folded-merged] mm-khugepaged-add-struct-collapse_control-fix-fix-fix.patch removed from -mm tree

[folded-merged] mm-khugepaged-add-struct-collapse_control-fix-fix-fix.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/khugepaged: fix struct collapse_control load_node definition
has been removed from the -mm tree.  Its filename was
     mm-khugepaged-add-struct-collapse_control-fix-fix-fix.patch

This patch was dropped because it was folded into mm-khugepaged-add-struct-collapse_control.patch

------------------------------------------------------
From: "Zach O'Keefe" <zokeefe@google.com>
Subject: mm/khugepaged: fix struct collapse_control load_node definition
Date: Fri, 2 Sep 2022 19:12:21 -0700

HPAGE_PMD_ORDER is used to determine a minimal amount of bits needed to
store per-node counters in struct collapse_control, defining the array to
be either a u16[HPAGE_PMD_ORDER] or u32[HPAGE_PMD_ORDER].

For some architectures/configs, HPAGE_PMD_ORDER isn't resolved at
preprocessor time (suitable for resolving preprocessor directives) but
rather expands into a compiler built-in that is resolved at compile-time. 
E.g.  for 32-bit MIPS (see link for full config):

---8<--
>> arch/mips/include/asm/pgtable.h:238:26: warning: "__builtin_ffs" is not defined, evaluates to 0 [-Wundef]
     238 | #define PTE_T_LOG2      (__builtin_ffs(sizeof(pte_t)) - 1)
         |                          ^~~~~~~~~~~~~
   arch/mips/include/asm/pgtable-32.h:65:43: note: in expansion of macro 'PTE_T_LOG2'
      65 | # define PGDIR_SHIFT    (2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
         |                                           ^~~~~~~~~~
   include/asm-generic/pgtable-nop4d.h:11:33: note: in expansion of macro 'PGDIR_SHIFT'
      11 | #define P4D_SHIFT               PGDIR_SHIFT
         |                                 ^~~~~~~~~~~
   include/asm-generic/pgtable-nopud.h:18:25: note: in expansion of macro 'P4D_SHIFT'
      18 | #define PUD_SHIFT       P4D_SHIFT
         |                         ^~~~~~~~~
   include/asm-generic/pgtable-nopmd.h:20:25: note: in expansion of macro 'PUD_SHIFT'
      20 | #define PMD_SHIFT       PUD_SHIFT
         |                         ^~~~~~~~~
   include/linux/huge_mm.h:109:25: note: in expansion of macro 'PMD_SHIFT'
     109 | #define HPAGE_PMD_SHIFT PMD_SHIFT
         |                         ^~~~~~~~~
   include/linux/huge_mm.h:105:26: note: in expansion of macro 'HPAGE_PMD_SHIFT'
     105 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
         |                          ^~~~~~~~~~~~~~~
   mm/khugepaged.c:90:5: note: in expansion of macro 'HPAGE_PMD_ORDER'
      90 | #if HPAGE_PMD_ORDER < 16
         |     ^~~~~~~~~~~~~~~
>> arch/mips/include/asm/pgtable.h:238:39: error: missing binary operator before token "("
     238 | #define PTE_T_LOG2      (__builtin_ffs(sizeof(pte_t)) - 1)
         |                                       ^
   arch/mips/include/asm/pgtable-32.h:65:43: note: in expansion of macro 'PTE_T_LOG2'
      65 | # define PGDIR_SHIFT    (2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
         |                                           ^~~~~~~~~~
   include/asm-generic/pgtable-nop4d.h:11:33: note: in expansion of macro 'PGDIR_SHIFT'
      11 | #define P4D_SHIFT               PGDIR_SHIFT
         |                                 ^~~~~~~~~~~
   include/asm-generic/pgtable-nopud.h:18:25: note: in expansion of macro 'P4D_SHIFT'
      18 | #define PUD_SHIFT       P4D_SHIFT
         |                         ^~~~~~~~~
   include/asm-generic/pgtable-nopmd.h:20:25: note: in expansion of macro 'PUD_SHIFT'
      20 | #define PMD_SHIFT       PUD_SHIFT
         |                         ^~~~~~~~~
   include/linux/huge_mm.h:109:25: note: in expansion of macro 'PMD_SHIFT'
     109 | #define HPAGE_PMD_SHIFT PMD_SHIFT
         |                         ^~~~~~~~~
   include/linux/huge_mm.h:105:26: note: in expansion of macro 'HPAGE_PMD_SHIFT'
     105 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
         |                          ^~~~~~~~~~~~~~~
   mm/khugepaged.c:90:5: note: in expansion of macro 'HPAGE_PMD_ORDER'
      90 | #if HPAGE_PMD_ORDER < 16
         |     ^~~~~~~~~~~~~~~
---8<--

load_node is already special-cased for CONFIG_PPC64 in
"mm-khugepaged-add-struct-collapse_control-fix-fix", and we could continue
down that path by #define'ing away edge cases, but I think at this point
it easier to just let load_node be an array of u32s.  If it's ever an
issue, we can revisit.

This essentially rolls back both:

"mm/khugepaged: use minimal bits to store num page < HPAGE_PMD_NR"
"mm-khugepaged-add-struct-collapse_control-fix-fix"

(though we'll leave it as a u32 vs an int).

Link: https://lore.kernel.org/linux-mm/202209021349.F73i5d6X-lkp@intel.com/
Link: https://lkml.kernel.org/r/20220903021221.1130021-1-zokeefe@google.com
Fixes: 5f7bb00bd9cd ("mm/khugepaged: use minimal bits to store num page < HPAGE_PMD_NR")
Fixes: 03053c821af2 ("mm-khugepaged-add-struct-collapse_control-fix-fix")
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/khugepaged.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

--- a/mm/khugepaged.c~mm-khugepaged-add-struct-collapse_control-fix-fix-fix
+++ a/mm/khugepaged.c
@@ -87,13 +87,8 @@ static struct kmem_cache *mm_slot_cache
 
 struct collapse_control {
 	/* Num pages scanned per node */
-#if defined(CONFIG_PPC64)
 	u32 node_load[MAX_NUMNODES];
-#elif HPAGE_PMD_ORDER < 16
-	u16 node_load[MAX_NUMNODES];
-#else
-	u32 node_load[MAX_NUMNODES];
-#endif
+
 	/* Last target selected in khugepaged_find_target_node() */
 	int last_target_node;
 };
_

Patches currently in -mm which might be from zokeefe@google.com are

mm-khugepaged-add-struct-collapse_control.patch
mm-khugepaged-dedup-and-simplify-hugepage-alloc-and-charging.patch
mm-khugepaged-pipe-enum-scan_result-codes-back-to-callers.patch
mm-khugepaged-add-flag-to-predicate-khugepaged-only-behavior.patch
mm-thp-add-flag-to-enforce-sysfs-thp-in-hugepage_vma_check.patch
mm-khugepaged-add-flag-to-predicate-khugepaged-only-behavior-fix.patch
mm-khugepaged-record-scan_pmd_mapped-when-scan_pmd-finds-hugepage.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-2.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-3.patch
mm-khugepaged-rename-prefix-of-shared-collapse-functions.patch
mm-madvise-add-madv_collapse-to-process_madvise.patch
mm-madvise-add-madv_collapse-to-process_madvise-fix.patch
selftests-vm-modularize-collapse-selftests.patch
selftests-vm-dedup-hugepage-allocation-logic.patch
selftests-vm-add-madv_collapse-collapse-context-to-selftests.patch
selftests-vm-add-selftest-to-verify-recollapse-of-thps.patch
selftests-vm-add-selftest-to-verify-multi-thp-collapse.patch
mm-shmem-add-flag-to-enforce-shmem-thp-in-hugepage_vma_check.patch
mm-khugepaged-attempt-to-map-file-shmem-backed-pte-mapped-thps-by-pmds.patch
mm-madvise-add-file-and-shmem-support-to-madv_collapse.patch
mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch
selftests-vm-dedup-thp-helpers.patch
selftests-vm-modularize-thp-collapse-memory-operations.patch
selftests-vm-add-thp-collapse-file-and-tmpfs-testing.patch
selftests-vm-add-thp-collapse-shmem-testing.patch
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
selftests-vm-add-selftest-for-madv_collapse-of-uffd-minor-memory.patch