[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: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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ee39b37b23
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@ -42,14 +42,6 @@
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*/
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#define TASK_SIZE (current->thread.task_size)
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/*
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* MM_VM_SIZE(mm) gives the maximum address (plus 1) which may contain a mapping for
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* address-space MM. Note that with 32-bit tasks, this is still DEFAULT_TASK_SIZE,
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* because the kernel may have installed helper-mappings above TASK_SIZE. For example,
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* for x86 emulation, the LDT and GDT are mapped above TASK_SIZE.
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*/
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#define MM_VM_SIZE(mm) DEFAULT_TASK_SIZE
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/*
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* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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@ -542,10 +542,6 @@ extern struct task_struct *last_task_used_altivec;
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#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
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TASK_SIZE_USER32 : TASK_SIZE_USER64)
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/* We can't actually tell the TASK_SIZE given just the mm, but default
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* to the 64-bit case to make sure that enough gets cleaned up. */
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#define MM_VM_SIZE(mm) TASK_SIZE_USER64
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/* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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@ -74,8 +74,6 @@ extern struct task_struct *last_task_used_math;
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#endif /* __s390x__ */
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#define MM_VM_SIZE(mm) DEFAULT_TASK_SIZE
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#define HAVE_ARCH_PICK_MMAP_LAYOUT
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typedef struct {
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@ -37,10 +37,6 @@ extern int sysctl_legacy_va_layout;
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#include <asm/processor.h>
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#include <asm/atomic.h>
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#ifndef MM_VM_SIZE
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#define MM_VM_SIZE(mm) ((TASK_SIZE + PGDIR_SIZE - 1) & PGDIR_MASK)
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#endif
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#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
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/*
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@ -582,13 +578,12 @@ struct zap_details {
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pgoff_t first_index; /* Lowest page->index to unmap */
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pgoff_t last_index; /* Highest page->index to unmap */
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spinlock_t *i_mmap_lock; /* For unmap_mapping_range: */
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unsigned long break_addr; /* Where unmap_vmas stopped */
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unsigned long truncate_count; /* Compare vm_truncate_count */
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};
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void zap_page_range(struct vm_area_struct *vma, unsigned long address,
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unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
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unsigned long size, struct zap_details *);
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int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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unsigned long unmap_vmas(struct mmu_gather **tlb, struct mm_struct *mm,
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struct vm_area_struct *start_vma, unsigned long start_addr,
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unsigned long end_addr, unsigned long *nr_accounted,
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struct zap_details *);
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28
mm/memory.c
28
mm/memory.c
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@ -645,7 +645,7 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
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* @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
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* @details: details of nonlinear truncation or shared cache invalidation
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*
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* Returns the number of vma's which were covered by the unmapping.
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* Returns the end address of the unmapping (restart addr if interrupted).
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*
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* Unmap all pages in the vma list. Called under page_table_lock.
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*
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@ -662,7 +662,7 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
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* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
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* drops the lock and schedules.
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*/
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int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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unsigned long unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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struct vm_area_struct *vma, unsigned long start_addr,
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unsigned long end_addr, unsigned long *nr_accounted,
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struct zap_details *details)
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@ -670,12 +670,11 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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unsigned long zap_bytes = ZAP_BLOCK_SIZE;
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unsigned long tlb_start = 0; /* For tlb_finish_mmu */
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int tlb_start_valid = 0;
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int ret = 0;
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unsigned long start = start_addr;
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spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
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int fullmm = tlb_is_full_mm(*tlbp);
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for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
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unsigned long start;
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unsigned long end;
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start = max(vma->vm_start, start_addr);
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@ -688,7 +687,6 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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if (vma->vm_flags & VM_ACCOUNT)
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*nr_accounted += (end - start) >> PAGE_SHIFT;
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ret++;
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while (start != end) {
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unsigned long block;
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@ -719,7 +717,6 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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if (i_mmap_lock) {
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/* must reset count of rss freed */
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*tlbp = tlb_gather_mmu(mm, fullmm);
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details->break_addr = start;
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goto out;
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}
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spin_unlock(&mm->page_table_lock);
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@ -733,7 +730,7 @@ int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
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}
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}
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out:
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return ret;
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return start; /* which is now the end (or restart) address */
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}
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/**
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@ -743,7 +740,7 @@ out:
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* @size: number of bytes to zap
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* @details: details of nonlinear truncation or shared cache invalidation
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*/
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void zap_page_range(struct vm_area_struct *vma, unsigned long address,
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unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
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unsigned long size, struct zap_details *details)
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{
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struct mm_struct *mm = vma->vm_mm;
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@ -753,15 +750,16 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long address,
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if (is_vm_hugetlb_page(vma)) {
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zap_hugepage_range(vma, address, size);
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return;
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return end;
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}
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lru_add_drain();
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spin_lock(&mm->page_table_lock);
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tlb = tlb_gather_mmu(mm, 0);
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unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details);
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end = unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details);
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tlb_finish_mmu(tlb, address, end);
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spin_unlock(&mm->page_table_lock);
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return end;
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}
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/*
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@ -1348,7 +1346,7 @@ no_new_page:
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* i_mmap_lock.
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*
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* In order to make forward progress despite repeatedly restarting some
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* large vma, note the break_addr set by unmap_vmas when it breaks out:
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* large vma, note the restart_addr from unmap_vmas when it breaks out:
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* and restart from that address when we reach that vma again. It might
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* have been split or merged, shrunk or extended, but never shifted: so
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* restart_addr remains valid so long as it remains in the vma's range.
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}
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}
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details->break_addr = end_addr;
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zap_page_range(vma, start_addr, end_addr - start_addr, details);
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restart_addr = zap_page_range(vma, start_addr,
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end_addr - start_addr, details);
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/*
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* We cannot rely on the break test in unmap_vmas:
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need_break = need_resched() ||
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need_lockbreak(details->i_mmap_lock);
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if (details->break_addr >= end_addr) {
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if (restart_addr >= end_addr) {
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/* We have now completed this vma: mark it so */
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vma->vm_truncate_count = details->truncate_count;
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if (!need_break)
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return 0;
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} else {
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/* Note restart_addr in vma's truncate_count field */
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vma->vm_truncate_count = details->break_addr;
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vma->vm_truncate_count = restart_addr;
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if (!need_break)
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goto again;
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}
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@ -1900,6 +1900,7 @@ void exit_mmap(struct mm_struct *mm)
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struct mmu_gather *tlb;
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struct vm_area_struct *vma = mm->mmap;
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unsigned long nr_accounted = 0;
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unsigned long end;
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lru_add_drain();
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@ -1908,10 +1909,10 @@ void exit_mmap(struct mm_struct *mm)
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flush_cache_mm(mm);
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tlb = tlb_gather_mmu(mm, 1);
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/* Use -1 here to ensure all VMAs in the mm are unmapped */
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mm->map_count -= unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL);
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end = unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL);
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vm_unacct_memory(nr_accounted);
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free_pgtables(&tlb, vma, 0, 0);
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tlb_finish_mmu(tlb, 0, MM_VM_SIZE(mm));
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tlb_finish_mmu(tlb, 0, end);
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mm->mmap = mm->mmap_cache = NULL;
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mm->mm_rb = RB_ROOT;
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vma = next;
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}
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BUG_ON(mm->map_count); /* This is just debugging */
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BUG_ON(mm->nr_ptes); /* This is just debugging */
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}
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