Commit dddbd541 authored by Linus Torvalds's avatar Linus Torvalds
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Merge branch 'vm-cleanups' (unmap_vma() interface cleanup) 

This series sanitizes the interface to unmap_vma().  The crazy interface
annoyed me no end when I was looking at unmap_single_vma(), which we can
spend quite a lot of time in (especially with loads that have a lot of
small fork/exec's: shell scripts etc).

Moving the nr_accounted calculations to where they belong at least
clarifies things a little.  I hope to come back to look at the
performance of this later, but if/when I get back to it I at least don't
have to see the crazy interfaces any more.

* vm-cleanups:
  vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces
  vm: simplify unmap_vmas() calling convention
parents 76e10d15 4f74d2c8

include/linux/mm.h

+2 −4
Original line number Diff line number Diff line
@@ -896,10 +896,8 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, 
		unsigned long size);

void zap_page_range(struct vm_area_struct *vma, unsigned long address,

		unsigned long size, struct zap_details *);

void unmap_vmas(struct mmu_gather *tlb,

		struct vm_area_struct *start_vma, unsigned long start_addr,

		unsigned long end_addr, unsigned long *nr_accounted,

		struct zap_details *);

void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,

		unsigned long start, unsigned long end);



/**

 * mm_walk - callbacks for walk_page_range

mm/memory.c

+11 −17
Original line number Diff line number Diff line
@@ -1295,7 +1295,7 @@ static void unmap_page_range(struct mmu_gather *tlb, 


static void unmap_single_vma(struct mmu_gather *tlb,

		struct vm_area_struct *vma, unsigned long start_addr,

		unsigned long end_addr, unsigned long *nr_accounted,

		unsigned long end_addr,

		struct zap_details *details)

{

	unsigned long start = max(vma->vm_start, start_addr);
@@ -1307,9 +1307,6 @@ static void unmap_single_vma(struct mmu_gather *tlb, 
	if (end <= vma->vm_start)

		return;



	if (vma->vm_flags & VM_ACCOUNT)

		*nr_accounted += (end - start) >> PAGE_SHIFT;



	if (unlikely(is_pfn_mapping(vma)))

		untrack_pfn_vma(vma, 0, 0);
@@ -1339,8 +1336,6 @@ static void unmap_single_vma(struct mmu_gather *tlb, 
 * @vma: the starting vma

 * @start_addr: virtual address at which to start unmapping

 * @end_addr: virtual address at which to end unmapping

 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here

 * @details: details of nonlinear truncation or shared cache invalidation

 *

 * Unmap all pages in the vma list.

 *
@@ -1355,15 +1350,13 @@ static void unmap_single_vma(struct mmu_gather *tlb, 
 */

void unmap_vmas(struct mmu_gather *tlb,

		struct vm_area_struct *vma, unsigned long start_addr,

		unsigned long end_addr, unsigned long *nr_accounted,

		struct zap_details *details)

		unsigned long end_addr)

{

	struct mm_struct *mm = vma->vm_mm;



	mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);

	for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)

		unmap_single_vma(tlb, vma, start_addr, end_addr, nr_accounted,

				 details);

		unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);

	mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);

}
@@ -1376,19 +1369,21 @@ void unmap_vmas(struct mmu_gather *tlb, 
 *

 * Caller must protect the VMA list

 */

void zap_page_range(struct vm_area_struct *vma, unsigned long address,

void zap_page_range(struct vm_area_struct *vma, unsigned long start,

		unsigned long size, struct zap_details *details)

{

	struct mm_struct *mm = vma->vm_mm;

	struct mmu_gather tlb;

	unsigned long end = address + size;

	unsigned long nr_accounted = 0;

	unsigned long end = start + size;



	lru_add_drain();

	tlb_gather_mmu(&tlb, mm, 0);

	update_hiwater_rss(mm);

	unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);

	tlb_finish_mmu(&tlb, address, end);

	mmu_notifier_invalidate_range_start(mm, start, end);

	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)

		unmap_single_vma(&tlb, vma, start, end, details);

	mmu_notifier_invalidate_range_end(mm, start, end);

	tlb_finish_mmu(&tlb, start, end);

}



/**
@@ -1406,13 +1401,12 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr 
	struct mm_struct *mm = vma->vm_mm;

	struct mmu_gather tlb;

	unsigned long end = address + size;

	unsigned long nr_accounted = 0;



	lru_add_drain();

	tlb_gather_mmu(&tlb, mm, 0);

	update_hiwater_rss(mm);

	mmu_notifier_invalidate_range_start(mm, address, end);

	unmap_single_vma(&tlb, vma, address, end, &nr_accounted, details);

	unmap_single_vma(&tlb, vma, address, end, details);

	mmu_notifier_invalidate_range_end(mm, address, end);

	tlb_finish_mmu(&tlb, address, end);

}

mm/mmap.c

+12 −6
Original line number Diff line number Diff line
@@ -1889,15 +1889,20 @@ find_extend_vma(struct mm_struct * mm, unsigned long addr) 
 */

static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)

{

	unsigned long nr_accounted = 0;



	/* Update high watermark before we lower total_vm */

	update_hiwater_vm(mm);

	do {

		long nrpages = vma_pages(vma);



		if (vma->vm_flags & VM_ACCOUNT)

			nr_accounted += nrpages;

		mm->total_vm -= nrpages;

		vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);

		vma = remove_vma(vma);

	} while (vma);

	vm_unacct_memory(nr_accounted);

	validate_mm(mm);

}
@@ -1912,13 +1917,11 @@ static void unmap_region(struct mm_struct *mm, 
{

	struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;

	struct mmu_gather tlb;

	unsigned long nr_accounted = 0;



	lru_add_drain();

	tlb_gather_mmu(&tlb, mm, 0);

	update_hiwater_rss(mm);

	unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);

	vm_unacct_memory(nr_accounted);

	unmap_vmas(&tlb, vma, start, end);

	free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,

				 next ? next->vm_start : 0);

	tlb_finish_mmu(&tlb, start, end);
@@ -2305,8 +2308,7 @@ void exit_mmap(struct mm_struct *mm) 
	tlb_gather_mmu(&tlb, mm, 1);

	/* update_hiwater_rss(mm) here? but nobody should be looking */

	/* Use -1 here to ensure all VMAs in the mm are unmapped */

	unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);

	vm_unacct_memory(nr_accounted);

	unmap_vmas(&tlb, vma, 0, -1);



	free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);

	tlb_finish_mmu(&tlb, 0, -1);
@@ -2315,8 +2317,12 @@ void exit_mmap(struct mm_struct *mm) 
	 * Walk the list again, actually closing and freeing it,

	 * with preemption enabled, without holding any MM locks.

	 */

	while (vma)

	while (vma) {

		if (vma->vm_flags & VM_ACCOUNT)

			nr_accounted += vma_pages(vma);

		vma = remove_vma(vma);

	}

	vm_unacct_memory(nr_accounted);



	BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);

}

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