Commit 15a23ffa authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

[PATCH] mm: tlb_gather_mmu get_cpu_var 



tlb_gather_mmu dates from before kernel preemption was allowed, and uses
smp_processor_id or __get_cpu_var to find its per-cpu mmu_gather.  That works
because it's currently only called after getting page_table_lock, which is not
dropped until after the matching tlb_finish_mmu.  But don't rely on that, it
will soon change: now disable preemption internally by proper get_cpu_var in
tlb_gather_mmu, put_cpu_var in tlb_finish_mmu.

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7be7a546

include/asm-arm/tlb.h

+3 −2
Original line number Diff line number Diff line
@@ -39,8 +39,7 @@ DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 
static inline struct mmu_gather *

tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)

{

	int cpu = smp_processor_id();

	struct mmu_gather *tlb = &per_cpu(mmu_gathers, cpu);

	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);



	tlb->mm = mm;

	tlb->freed = 0;
@@ -65,6 +64,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 


	/* keep the page table cache within bounds */

	check_pgt_cache();



	put_cpu_var(mmu_gathers);

}



static inline unsigned int tlb_is_full_mm(struct mmu_gather *tlb)

include/asm-arm26/tlb.h

+4 −3
Original line number Diff line number Diff line
@@ -17,13 +17,12 @@ struct mmu_gather { 
        unsigned int            avoided_flushes;

};



extern struct mmu_gather mmu_gathers[NR_CPUS];

DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);



static inline struct mmu_gather *

tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)

{

        int cpu = smp_processor_id();

        struct mmu_gather *tlb = &mmu_gathers[cpu];

        struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);



        tlb->mm = mm;

        tlb->freed = 0;
@@ -52,6 +51,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 


        /* keep the page table cache within bounds */

        check_pgt_cache();



        put_cpu_var(mmu_gathers);

}

include/asm-generic/tlb.h

+5 −5
Original line number Diff line number Diff line
@@ -35,9 +35,7 @@ 
#endif



/* struct mmu_gather is an opaque type used by the mm code for passing around

 * any data needed by arch specific code for tlb_remove_page.  This structure

 * can be per-CPU or per-MM as the page table lock is held for the duration of

 * TLB shootdown.

 * any data needed by arch specific code for tlb_remove_page.

 */

struct mmu_gather {

	struct mm_struct	*mm;
@@ -57,7 +55,7 @@ DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 
static inline struct mmu_gather *

tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)

{

	struct mmu_gather *tlb = &per_cpu(mmu_gathers, smp_processor_id());

	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);



	tlb->mm = mm;
@@ -85,7 +83,7 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 


/* tlb_finish_mmu

 *	Called at the end of the shootdown operation to free up any resources

 *	that were required.  The page table lock is still held at this point.

 *	that were required.

 */

static inline void

tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
@@ -101,6 +99,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 


	/* keep the page table cache within bounds */

	check_pgt_cache();



	put_cpu_var(mmu_gathers);

}



static inline unsigned int

include/asm-ia64/tlb.h

+4 −2
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long e 
static inline struct mmu_gather *

tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush)

{

	struct mmu_gather *tlb = &__get_cpu_var(mmu_gathers);

	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);



	tlb->mm = mm;

	/*
@@ -154,7 +154,7 @@ tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush) 


/*

 * Called at the end of the shootdown operation to free up any resources that were

 * collected.  The page table lock is still held at this point.

 * collected.

 */

static inline void

tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
@@ -174,6 +174,8 @@ tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) 


	/* keep the page table cache within bounds */

	check_pgt_cache();



	put_cpu_var(mmu_gathers);

}



static inline unsigned int

include/asm-sparc64/tlb.h

+3 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ extern void flush_tlb_pending(void); 


static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)

{

	struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);

	struct mmu_gather *mp = &get_cpu_var(mmu_gathers);



	BUG_ON(mp->tlb_nr);
@@ -97,6 +97,8 @@ static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, un 


	/* keep the page table cache within bounds */

	check_pgt_cache();



	put_cpu_var(mmu_gathers);

}



static inline unsigned int tlb_is_full_mm(struct mmu_gather *mp)

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