diff options
Diffstat (limited to 'mm/mmap.c')
-rw-r--r-- | mm/mmap.c | 57 |
1 files changed, 44 insertions, 13 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index de54acd9942f..da3fa90a0aae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1175,7 +1175,12 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, (!vma || addr + len <= vma->vm_start)) return addr; } - start_addr = addr = mm->free_area_cache; + if (len > mm->cached_hole_size) { + start_addr = addr = mm->free_area_cache; + } else { + start_addr = addr = TASK_UNMAPPED_BASE; + mm->cached_hole_size = 0; + } full_search: for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { @@ -1186,7 +1191,9 @@ full_search: * some holes. */ if (start_addr != TASK_UNMAPPED_BASE) { - start_addr = addr = TASK_UNMAPPED_BASE; + addr = TASK_UNMAPPED_BASE; + start_addr = addr; + mm->cached_hole_size = 0; goto full_search; } return -ENOMEM; @@ -1198,19 +1205,22 @@ full_search: mm->free_area_cache = addr + len; return addr; } + if (addr + mm->cached_hole_size < vma->vm_start) + mm->cached_hole_size = vma->vm_start - addr; addr = vma->vm_end; } } #endif -void arch_unmap_area(struct vm_area_struct *area) +void arch_unmap_area(struct mm_struct *mm, unsigned long addr) { /* * Is this a new hole at the lowest possible address? */ - if (area->vm_start >= TASK_UNMAPPED_BASE && - area->vm_start < area->vm_mm->free_area_cache) - area->vm_mm->free_area_cache = area->vm_start; + if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache) { + mm->free_area_cache = addr; + mm->cached_hole_size = ~0UL; + } } /* @@ -1240,6 +1250,12 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } + /* check if free_area_cache is useful for us */ + if (len <= mm->cached_hole_size) { + mm->cached_hole_size = 0; + mm->free_area_cache = mm->mmap_base; + } + /* either no address requested or can't fit in requested address hole */ addr = mm->free_area_cache; @@ -1251,6 +1267,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return (mm->free_area_cache = addr-len); } + if (mm->mmap_base < len) + goto bottomup; + addr = mm->mmap_base-len; do { @@ -1264,38 +1283,45 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, /* remember the address as a hint for next time */ return (mm->free_area_cache = addr); + /* remember the largest hole we saw so far */ + if (addr + mm->cached_hole_size < vma->vm_start) + mm->cached_hole_size = vma->vm_start - addr; + /* try just below the current vma->vm_start */ addr = vma->vm_start-len; } while (len < vma->vm_start); +bottomup: /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario * can happen with large stack limits and large mmap() * allocations. */ - mm->free_area_cache = TASK_UNMAPPED_BASE; + mm->cached_hole_size = ~0UL; + mm->free_area_cache = TASK_UNMAPPED_BASE; addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags); /* * Restore the topdown base: */ mm->free_area_cache = mm->mmap_base; + mm->cached_hole_size = ~0UL; return addr; } #endif -void arch_unmap_area_topdown(struct vm_area_struct *area) +void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr) { /* * Is this a new hole at the highest possible address? */ - if (area->vm_end > area->vm_mm->free_area_cache) - area->vm_mm->free_area_cache = area->vm_end; + if (addr > mm->free_area_cache) + mm->free_area_cache = addr; /* dont allow allocations above current base */ - if (area->vm_mm->free_area_cache > area->vm_mm->mmap_base) - area->vm_mm->free_area_cache = area->vm_mm->mmap_base; + if (mm->free_area_cache > mm->mmap_base) + mm->free_area_cache = mm->mmap_base; } unsigned long @@ -1595,7 +1621,6 @@ static void unmap_vma(struct mm_struct *mm, struct vm_area_struct *area) if (area->vm_flags & VM_LOCKED) area->vm_mm->locked_vm -= len >> PAGE_SHIFT; vm_stat_unaccount(area); - area->vm_mm->unmap_area(area); remove_vm_struct(area); } @@ -1649,6 +1674,7 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma, { struct vm_area_struct **insertion_point; struct vm_area_struct *tail_vma = NULL; + unsigned long addr; insertion_point = (prev ? &prev->vm_next : &mm->mmap); do { @@ -1659,6 +1685,11 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma, } while (vma && vma->vm_start < end); *insertion_point = vma; tail_vma->vm_next = NULL; + if (mm->unmap_area == arch_unmap_area) + addr = prev ? prev->vm_end : mm->mmap_base; + else + addr = vma ? vma->vm_start : mm->mmap_base; + mm->unmap_area(mm, addr); mm->mmap_cache = NULL; /* Kill the cache. */ } |