Commit 016c4d92 authored by Rik van Riel's avatar Rik van Riel Committed by Peter Zijlstra
Browse files

x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range 



Add an argument to flush_tlb_mm_range to indicate whether page tables
are about to be freed after this TLB flush. This allows for an
optimization of flush_tlb_mm_range to skip CPUs in lazy TLB mode.

No functional changes.

Cc: npiggin@gmail.com
Cc: mingo@kernel.org
Cc: will.deacon@arm.com
Cc: songliubraving@fb.com
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Cc: hpa@zytor.com
Signed-off-by: default avatarRik van Riel <riel@surriel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180926035844.1420-6-riel@surriel.com
parent 7d49b28a

arch/x86/include/asm/tlb.h

+1 −1
Original line number Diff line number Diff line
@@ -20,7 +20,7 @@ static inline void tlb_flush(struct mmu_gather *tlb) 
		end = tlb->end;

	}



	flush_tlb_mm_range(tlb->mm, start, end, stride_shift);

	flush_tlb_mm_range(tlb->mm, start, end, stride_shift, tlb->freed_tables);

}



/*

arch/x86/include/asm/tlbflush.h

+6 −4
Original line number Diff line number Diff line
@@ -536,22 +536,24 @@ struct flush_tlb_info { 


#define local_flush_tlb() __flush_tlb()



#define flush_tlb_mm(mm)	flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL)

#define flush_tlb_mm(mm)						\

		flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)



#define flush_tlb_range(vma, start, end)				\

	flush_tlb_mm_range((vma)->vm_mm, start, end,			\

			   ((vma)->vm_flags & VM_HUGETLB)		\

				? huge_page_shift(hstate_vma(vma))	\

				: PAGE_SHIFT)

				: PAGE_SHIFT, false)



extern void flush_tlb_all(void);

extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,

				unsigned long end, unsigned int stride_shift);

				unsigned long end, unsigned int stride_shift,

				bool freed_tables);

extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);



static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)

{

	flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT);

	flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false);

}



void native_flush_tlb_others(const struct cpumask *cpumask,

arch/x86/kernel/ldt.c

+1 −1
Original line number Diff line number Diff line
@@ -273,7 +273,7 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot) 
	map_ldt_struct_to_user(mm);



	va = (unsigned long)ldt_slot_va(slot);

	flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, PAGE_SHIFT);

	flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, PAGE_SHIFT, false);



	ldt->slot = slot;

	return 0;

arch/x86/kernel/vm86_32.c

+1 −1
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ static void mark_screen_rdonly(struct mm_struct *mm) 
	pte_unmap_unlock(pte, ptl);

out:

	up_write(&mm->mmap_sem);

	flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, PAGE_SHIFT);

	flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, PAGE_SHIFT, false);

}

arch/x86/mm/tlb.c

+2 −1
Original line number Diff line number Diff line
@@ -609,7 +609,8 @@ void native_flush_tlb_others(const struct cpumask *cpumask, 
static unsigned long tlb_single_page_flush_ceiling __read_mostly = 33;



void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,

				unsigned long end, unsigned int stride_shift)

				unsigned long end, unsigned int stride_shift,

				bool freed_tables)

{

	int cpu;

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