Commit ee39b37b authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

[PATCH] freepgt: remove MM_VM_SIZE(mm) 



There's only one usage of MM_VM_SIZE(mm) left, and it's a troublesome macro
because mm doesn't contain the (32-bit emulation?) info needed.  But it too is
only needed because we ignore the end from the vma list.

We could make flush_pgtables return that end, or unmap_vmas.  Choose the
latter, since it's a natural fit with unmap_mapping_range_vma needing to know
its restart addr.  This does make more than minimal change, but if unmap_vmas
had returned the end before, this is how we'd have done it, rather than
storing the break_addr in zap_details.

unmap_vmas used to return count of vmas scanned, but that's just debug which
hasn't been useful in a while; and if we want the map_count 0 on exit check
back, it can easily come from the final remove_vm_struct loop.

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 e0da382c

include/asm-ia64/processor.h

+0 −8
Original line number Diff line number Diff line
@@ -42,14 +42,6 @@ 
 */

#define TASK_SIZE		(current->thread.task_size)



/*

 * MM_VM_SIZE(mm) gives the maximum address (plus 1) which may contain a mapping for

 * address-space MM.  Note that with 32-bit tasks, this is still DEFAULT_TASK_SIZE,

 * because the kernel may have installed helper-mappings above TASK_SIZE.  For example,

 * for x86 emulation, the LDT and GDT are mapped above TASK_SIZE.

 */

#define MM_VM_SIZE(mm)		DEFAULT_TASK_SIZE



/*

 * This decides where the kernel will search for a free chunk of vm

 * space during mmap's.

include/asm-ppc64/processor.h

+0 −4
Original line number Diff line number Diff line
@@ -542,10 +542,6 @@ extern struct task_struct *last_task_used_altivec; 
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \

		TASK_SIZE_USER32 : TASK_SIZE_USER64)



/* We can't actually tell the TASK_SIZE given just the mm, but default

 * to the 64-bit case to make sure that enough gets cleaned up. */

#define MM_VM_SIZE(mm)	TASK_SIZE_USER64



/* This decides where the kernel will search for a free chunk of vm

 * space during mmap's.

 */

include/asm-s390/processor.h

+0 −2
Original line number Diff line number Diff line
@@ -74,8 +74,6 @@ extern struct task_struct *last_task_used_math; 


#endif /* __s390x__ */



#define MM_VM_SIZE(mm)		DEFAULT_TASK_SIZE



#define HAVE_ARCH_PICK_MMAP_LAYOUT



typedef struct {

include/linux/mm.h

+2 −7
Original line number Diff line number Diff line
@@ -37,10 +37,6 @@ extern int sysctl_legacy_va_layout; 
#include <asm/processor.h>

#include <asm/atomic.h>



#ifndef MM_VM_SIZE

#define MM_VM_SIZE(mm)	((TASK_SIZE + PGDIR_SIZE - 1) & PGDIR_MASK)

#endif



#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))



/*
@@ -582,13 +578,12 @@ struct zap_details { 
	pgoff_t	first_index;			/* Lowest page->index to unmap */

	pgoff_t last_index;			/* Highest page->index to unmap */

	spinlock_t *i_mmap_lock;		/* For unmap_mapping_range: */

	unsigned long break_addr;		/* Where unmap_vmas stopped */

	unsigned long truncate_count;		/* Compare vm_truncate_count */

};



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

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

		unsigned long size, struct zap_details *);

int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,

unsigned long unmap_vmas(struct mmu_gather **tlb, struct mm_struct *mm,

		struct vm_area_struct *start_vma, unsigned long start_addr,

		unsigned long end_addr, unsigned long *nr_accounted,

		struct zap_details *);

mm/memory.c

+13 −15
Original line number Diff line number Diff line
@@ -645,7 +645,7 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 
 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here

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

 *

 * Returns the number of vma's which were covered by the unmapping.

 * Returns the end address of the unmapping (restart addr if interrupted).

 *

 * Unmap all pages in the vma list.  Called under page_table_lock.

 *
@@ -662,7 +662,7 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 
 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()

 * drops the lock and schedules.

 */

int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,

unsigned long unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,

		struct vm_area_struct *vma, unsigned long start_addr,

		unsigned long end_addr, unsigned long *nr_accounted,

		struct zap_details *details)
@@ -670,12 +670,11 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, 
	unsigned long zap_bytes = ZAP_BLOCK_SIZE;

	unsigned long tlb_start = 0;	/* For tlb_finish_mmu */

	int tlb_start_valid = 0;

	int ret = 0;

	unsigned long start = start_addr;

	spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;

	int fullmm = tlb_is_full_mm(*tlbp);



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

		unsigned long start;

		unsigned long end;



		start = max(vma->vm_start, start_addr);
@@ -688,7 +687,6 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, 
		if (vma->vm_flags & VM_ACCOUNT)

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



		ret++;

		while (start != end) {

			unsigned long block;
@@ -719,7 +717,6 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, 
				if (i_mmap_lock) {

					/* must reset count of rss freed */

					*tlbp = tlb_gather_mmu(mm, fullmm);

					details->break_addr = start;

					goto out;

				}

				spin_unlock(&mm->page_table_lock);
@@ -733,7 +730,7 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, 
		}

	}

out:

	return ret;

	return start;	/* which is now the end (or restart) address */

}



/**
@@ -743,7 +740,7 @@ out: 
 * @size: number of bytes to zap

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

 */

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

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

		unsigned long size, struct zap_details *details)

{

	struct mm_struct *mm = vma->vm_mm;
@@ -753,15 +750,16 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long address, 


	if (is_vm_hugetlb_page(vma)) {

		zap_hugepage_range(vma, address, size);

		return;

		return end;

	}



	lru_add_drain();

	spin_lock(&mm->page_table_lock);

	tlb = tlb_gather_mmu(mm, 0);

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

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

	tlb_finish_mmu(tlb, address, end);

	spin_unlock(&mm->page_table_lock);

	return end;

}



/*
@@ -1348,7 +1346,7 @@ no_new_page: 
 * i_mmap_lock.

 *

 * In order to make forward progress despite repeatedly restarting some

 * large vma, note the break_addr set by unmap_vmas when it breaks out:

 * large vma, note the restart_addr from unmap_vmas when it breaks out:

 * and restart from that address when we reach that vma again.  It might

 * have been split or merged, shrunk or extended, but never shifted: so

 * restart_addr remains valid so long as it remains in the vma's range.
@@ -1386,8 +1384,8 @@ again: 
		}

	}



	details->break_addr = end_addr;

	zap_page_range(vma, start_addr, end_addr - start_addr, details);

	restart_addr = zap_page_range(vma, start_addr,

					end_addr - start_addr, details);



	/*

	 * We cannot rely on the break test in unmap_vmas:
@@ -1398,14 +1396,14 @@ again: 
	need_break = need_resched() ||

			need_lockbreak(details->i_mmap_lock);



	if (details->break_addr >= end_addr) {

	if (restart_addr >= end_addr) {

		/* We have now completed this vma: mark it so */

		vma->vm_truncate_count = details->truncate_count;

		if (!need_break)

			return 0;

	} else {

		/* Note restart_addr in vma's truncate_count field */

		vma->vm_truncate_count = details->break_addr;

		vma->vm_truncate_count = restart_addr;

		if (!need_break)

			goto again;

	}

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