Subject: + mm-create-a-separate-slab-for-page-ptl-allocation.patch added to -mm tree
To: kirill.shutemov@xxxxxxxxxxxxxxx,mingo@xxxxxxx,peterz@xxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Thu, 07 Nov 2013 14:00:19 -0800
The patch titled
Subject: mm: create a separate slab for page->ptl allocation
has been added to the -mm tree. Its filename is
mm-create-a-separate-slab-for-page-ptl-allocation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-create-a-separate-slab-for-page-ptl-allocation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-create-a-separate-slab-for-page-ptl-allocation.patch
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From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm: create a separate slab for page->ptl allocation
If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64 is
72 bytes. For page->ptl they will be allocated from kmalloc-96 slab, so
we loose 24 on each. An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.
Let's create a separate slab for page->ptl allocation to solve this.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 9 +++++++++
init/main.c | 2 +-
mm/memory.c | 7 +++++++
3 files changed, 17 insertions(+), 1 deletion(-)
diff -puN include/linux/mm.h~mm-create-a-separate-slab-for-page-ptl-allocation include/linux/mm.h
--- a/include/linux/mm.h~mm-create-a-separate-slab-for-page-ptl-allocation
+++ a/include/linux/mm.h
@@ -1318,6 +1318,7 @@ static inline pmd_t *pmd_alloc(struct mm
#if USE_SPLIT_PTE_PTLOCKS
#if BLOATED_SPINLOCKS
+void __init ptlock_cache_init(void);
extern bool ptlock_alloc(struct page *page);
extern void ptlock_free(struct page *page);
@@ -1326,6 +1327,7 @@ static inline spinlock_t *ptlock_ptr(str
return page->ptl;
}
#else /* BLOATED_SPINLOCKS */
+static inline void ptlock_cache_init(void) {}
static inline bool ptlock_alloc(struct page *page)
{
return true;
@@ -1378,10 +1380,17 @@ static inline spinlock_t *pte_lockptr(st
{
return &mm->page_table_lock;
}
+static inline void ptlock_cache_init(void) {}
static inline bool ptlock_init(struct page *page) { return true; }
static inline void pte_lock_deinit(struct page *page) {}
#endif /* USE_SPLIT_PTE_PTLOCKS */
+static inline void pgtable_init(void)
+{
+ ptlock_cache_init();
+ pgtable_cache_init();
+}
+
static inline bool pgtable_page_ctor(struct page *page)
{
inc_zone_page_state(page, NR_PAGETABLE);
diff -puN init/main.c~mm-create-a-separate-slab-for-page-ptl-allocation init/main.c
--- a/init/main.c~mm-create-a-separate-slab-for-page-ptl-allocation
+++ a/init/main.c
@@ -476,7 +476,7 @@ static void __init mm_init(void)
mem_init();
kmem_cache_init();
percpu_init_late();
- pgtable_cache_init();
+ pgtable_init();
vmalloc_init();
}
diff -puN mm/memory.c~mm-create-a-separate-slab-for-page-ptl-allocation mm/memory.c
--- a/mm/memory.c~mm-create-a-separate-slab-for-page-ptl-allocation
+++ a/mm/memory.c
@@ -4272,6 +4272,13 @@ void copy_user_huge_page(struct page *ds
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
#if USE_SPLIT_PTE_PTLOCKS && BLOATED_SPINLOCKS
+static struct kmem_cache *page_ptl_cachep;
+void __init ptlock_cache_init(void)
+{
+ page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0,
+ SLAB_PANIC, NULL);
+}
+
bool ptlock_alloc(struct page *page)
{
spinlock_t *ptl;
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
x86-mm-get-aslr-work-for-hugetlb-mappings.patch
mm-huge_memoryc-fix-stale-comments-of-transparent_hugepage_flags.patch
mm-thp-cleanup-mv-alloc_hugepage-to-better-place.patch
mm-thp-khugepaged-add-policy-for-finding-target-node.patch
mm-thp-khugepaged-add-policy-for-finding-target-node-fix.patch
mm-drop-actor-argument-of-do_generic_file_read.patch
mm-drop-actor-argument-of-do_generic_file_read-fix.patch
mm-avoid-increase-sizeofstruct-page-due-to-split-page-table-lock.patch
mm-rename-use_split_ptlocks-to-use_split_pte_ptlocks.patch
mm-convert-mm-nr_ptes-to-atomic_long_t.patch
mm-introduce-api-for-split-page-table-lock-for-pmd-level.patch
mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch
mm-thp-move-ptl-taking-inside-page_check_address_pmd.patch
mm-thp-do-not-access-mm-pmd_huge_pte-directly.patch
mm-hugetlb-convert-hugetlbfs-to-use-split-pmd-lock.patch
mm-hugetlb-convert-hugetlbfs-to-use-split-pmd-lock-checkpatch-fixes.patch
mm-convert-the-rest-to-new-page-table-lock-api.patch
mm-implement-split-page-table-lock-for-pmd-level.patch
x86-mm-enable-split-page-table-lock-for-pmd-level.patch
x86-mm-enable-split-page-table-lock-for-pmd-level-checkpatch-fixes.patch
x86-add-missed-pgtable_pmd_page_ctor-dtor-calls-for-preallocated-pmds.patch
cris-fix-potential-null-pointer-dereference.patch
m32r-fix-potential-null-pointer-dereference.patch
xtensa-fix-potential-null-pointer-dereference.patch
mm-allow-pgtable_page_ctor-to-fail.patch
microblaze-add-missing-pgtable_page_ctor-dtor-calls.patch
mn10300-add-missing-pgtable_page_ctor-dtor-calls.patch
openrisc-add-missing-pgtable_page_ctor-dtor-calls.patch
alpha-handle-pgtable_page_ctor-fail.patch
arc-handle-pgtable_page_ctor-fail.patch
arm-handle-pgtable_page_ctor-fail.patch
arm64-handle-pgtable_page_ctor-fail.patch
avr32-handle-pgtable_page_ctor-fail.patch
cris-handle-pgtable_page_ctor-fail.patch
frv-handle-pgtable_page_ctor-fail.patch
hexagon-handle-pgtable_page_ctor-fail.patch
ia64-handle-pgtable_page_ctor-fail.patch
m32r-handle-pgtable_page_ctor-fail.patch
m68k-handle-pgtable_page_ctor-fail.patch
m68k-handle-pgtable_page_ctor-fail-fix.patch
m68k-handle-pgtable_page_ctor-fail-fix-fix.patch
metag-handle-pgtable_page_ctor-fail.patch
mips-handle-pgtable_page_ctor-fail.patch
parisc-handle-pgtable_page_ctor-fail.patch
powerpc-handle-pgtable_page_ctor-fail.patch
s390-handle-pgtable_page_ctor-fail.patch
score-handle-pgtable_page_ctor-fail.patch
sh-handle-pgtable_page_ctor-fail.patch
sparc-handle-pgtable_page_ctor-fail.patch
tile-handle-pgtable_page_ctor-fail.patch
um-handle-pgtable_page_ctor-fail.patch
unicore32-handle-pgtable_page_ctor-fail.patch
x86-handle-pgtable_page_ctor-fail.patch
xtensa-handle-pgtable_page_ctor-fail.patch
iommu-arm-smmu-handle-pgtable_page_ctor-fail.patch
xtensa-use-buddy-allocator-for-pte-table.patch
mm-dynamically-allocate-page-ptl-if-it-cannot-be-embedded-to-struct-page.patch
mm-properly-separate-the-bloated-ptl-from-the-regular-case.patch
mm-create-a-separate-slab-for-page-ptl-allocation.patch
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