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sparc64: Do not save/restore interrupts in get_new_mmu_context() 

get_new_mmu_context() is always called with interrupts disabled.
So it's possible to do this micro optimization.

(Also fix the comment to switch_mm, which is called in both cases)

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kirill Tkhai 2013-04-09 00:29:46 +04:00 committed by David S. Miller
parent 598ec971dd
commit 07df841877
2 changed files with 3 additions and 4 deletions
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2
arch/sparc/include/asm/mmu_context_64.h
View File

@ -68,7 +68,7 @@ extern void smp_tsb_sync(struct mm_struct *mm);
extern void __flush_tlb_mm(unsigned long, unsigned long); extern void __flush_tlb_mm(unsigned long, unsigned long);
/* Switch the current MM context. Interrupts are disabled. */ /* Switch the current MM context. */
static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
{ {
unsigned long ctx_valid, flags; unsigned long ctx_valid, flags;

5
arch/sparc/mm/init_64.c
View File

@ -681,10 +681,9 @@ void get_new_mmu_context(struct mm_struct *mm)
{ {
unsigned long ctx, new_ctx; unsigned long ctx, new_ctx;
unsigned long orig_pgsz_bits; unsigned long orig_pgsz_bits;
unsigned long flags;
int new_version; int new_version;
spin_lock_irqsave(&ctx_alloc_lock, flags); spin_lock(&ctx_alloc_lock);
orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK); orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK);
ctx = (tlb_context_cache + 1) & CTX_NR_MASK; ctx = (tlb_context_cache + 1) & CTX_NR_MASK;
new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx); new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx);
@ -720,7 +719,7 @@ void get_new_mmu_context(struct mm_struct *mm)
out: out:
tlb_context_cache = new_ctx; tlb_context_cache = new_ctx;
mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits; mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits;
spin_unlock_irqrestore(&ctx_alloc_lock, flags); spin_unlock(&ctx_alloc_lock);
if (unlikely(new_version)) if (unlikely(new_version))
smp_new_mmu_context_version(); smp_new_mmu_context_version();