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| author | Richard Kennedy <richard@rsk.demon.co.uk> | 2011-03-22 16:32:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-22 17:44:03 -0700 |
| commit | 481b4bb5e370aa69c1dc276bd08871ec01b41d2a (patch) | |
| tree | 11a276bc58c2eb9b0a00fe751c3bf81bc3240382 | |
| parent | cb240452bfc2ae9de7c840dd0fb3f5b33ce03c31 (diff) | |
| download | linux-481b4bb5e370aa69c1dc276bd08871ec01b41d2a.tar.bz2 | |
mm: mm_struct: remove 16 bytes of alignment padding on 64 bit builds
Reorder mm_struct to remove 16 bytes of alignment padding on 64 bit
builds. On my config this shrinks mm_struct by enough to fit in one
fewer cache lines and allows more objects per slab in mm_struct
kmem_cache under SLUB.
slabinfo before patch :-
Sizes (bytes) Slabs
--------------------------------
Object : 848 Total : 9
SlabObj: 896 Full : 2
SlabSiz: 16384 Partial: 5
Loss : 48 CpuSlab: 2
Align : 64 Objects: 18
slabinfo after :-
Sizes (bytes) Slabs
--------------------------------
Object : 832 Total : 7
SlabObj: 832 Full : 2
SlabSiz: 16384 Partial: 3
Loss : 0 CpuSlab: 2
Align : 64 Objects: 19
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mm_types.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 26bc4e2cd275..02aa5619709b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -237,8 +237,9 @@ struct mm_struct { atomic_t mm_users; /* How many users with user space? */ atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ int map_count; /* number of VMAs */ - struct rw_semaphore mmap_sem; + spinlock_t page_table_lock; /* Protects page tables and some counters */ + struct rw_semaphore mmap_sem; struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung * together off init_mm.mmlist, and are protected @@ -281,6 +282,9 @@ struct mm_struct { unsigned int token_priority; unsigned int last_interval; + /* How many tasks sharing this mm are OOM_DISABLE */ + atomic_t oom_disable_count; + unsigned long flags; /* Must use atomic bitops to access the bits */ struct core_state *core_state; /* coredumping support */ @@ -313,8 +317,6 @@ struct mm_struct { #ifdef CONFIG_TRANSPARENT_HUGEPAGE pgtable_t pmd_huge_pte; /* protected by page_table_lock */ #endif - /* How many tasks sharing this mm are OOM_DISABLE */ - atomic_t oom_disable_count; }; /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ |