The patch titled
Subject: mm/thp: make ALLOC_SPLIT_PTLOCKS dependent on USE_SPLIT_PTE_PTLOCKS
has been added to the -mm tree. Its filename is
mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks.patch
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------------------------------------------------------
From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: mm/thp: make ALLOC_SPLIT_PTLOCKS dependent on USE_SPLIT_PTE_PTLOCKS
Split ptlocks need not be defined and allocated unless they are being
used. ALLOC_SPLIT_PTLOCKS is inherently dependent on
USE_SPLIT_PTE_PTLOCKS. This just makes it explicit and clear. While here
drop the spinlock_t element from the struct page when
USE_SPLIT_PTE_PTLOCKS is not enabled.
Link: https://lkml.kernel.org/r/1621409586-5555-1-git-send-email-anshuman.khandual@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 2 ++
include/linux/mm_types_task.h | 5 +++++
mm/memory.c | 2 +-
3 files changed, 8 insertions(+), 1 deletion(-)
--- a/include/linux/mm_types.h~mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks
+++ a/include/linux/mm_types.h
@@ -152,11 +152,13 @@ struct page {
struct mm_struct *pt_mm; /* x86 pgds only */
atomic_t pt_frag_refcount; /* powerpc */
};
+#if USE_SPLIT_PTE_PTLOCKS
#if ALLOC_SPLIT_PTLOCKS
spinlock_t *ptl;
#else
spinlock_t ptl;
#endif
+#endif
};
struct { /* ZONE_DEVICE pages */
/** @pgmap: Points to the hosting device page map. */
--- a/include/linux/mm_types_task.h~mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks
+++ a/include/linux/mm_types_task.h
@@ -22,7 +22,12 @@
#define USE_SPLIT_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
#define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \
IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
+
+#if USE_SPLIT_PTE_PTLOCKS
#define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
+#else
+#define ALLOC_SPLIT_PTLOCKS 0
+#endif
/*
* The per task VMA cache array:
--- a/mm/memory.c~mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks
+++ a/mm/memory.c
@@ -5259,7 +5259,7 @@ long copy_huge_page_from_user(struct pag
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
-#if USE_SPLIT_PTE_PTLOCKS && ALLOC_SPLIT_PTLOCKS
+#if ALLOC_SPLIT_PTLOCKS
static struct kmem_cache *page_ptl_cachep;
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-thp-update-mm_structs-mm_anonpages-stat-for-huge-zero-pages.patch
mm-thp-make-alloc_split_ptlocks-dependent-on-use_split_pte_ptlocks.patch
mm-define-default-value-for-first_user_address.patch
