From 7ac40215c1201f9761683e3d98af81b6207b92ab Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Fri, 9 Nov 2012 15:05:17 +1100 Subject: [PATCH] Revert "mm: use vm_unmapped_area() on sparc64 architecture" This reverts commit f794b36b1a4f767d79fe3e7c5011f94aff18471f. --- arch/sparc/kernel/sys_sparc_64.c | 132 ++++++++++++++++++++++++------- 1 file changed, 102 insertions(+), 30 deletions(-) diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index db2db7940bcd..51b85feb8b97 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -102,7 +102,6 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi unsigned long task_size = TASK_SIZE; unsigned long start_addr; int do_color_align; - struct vm_unmapped_area_info info; if (flags & MAP_FIXED) { /* We do not accept a shared mapping if it would violate @@ -135,22 +134,50 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi return addr; } - info.flags = 0; - info.length = len; - info.low_limit = TASK_UNMAPPED_BASE; - info.high_limit = min(task_size, VA_EXCLUDE_START); - info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; - info.align_offset = pgoff << PAGE_SHIFT; - addr = vm_unmapped_area(&info); - - if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) { - VM_BUG_ON(addr != -ENOMEM); - info.low_limit = VA_EXCLUDE_END; - info.high_limit = task_size; - addr = vm_unmapped_area(&info); + 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; } - return addr; + task_size -= len; + +full_search: + if (do_color_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { + /* At this point: (!vma || addr < vma->vm_end). */ + if (addr < VA_EXCLUDE_START && + (addr + len) >= VA_EXCLUDE_START) { + addr = VA_EXCLUDE_END; + vma = find_vma(mm, VA_EXCLUDE_END); + } + if (unlikely(task_size < addr)) { + if (start_addr != TASK_UNMAPPED_BASE) { + start_addr = addr = TASK_UNMAPPED_BASE; + mm->cached_hole_size = 0; + goto full_search; + } + return -ENOMEM; + } + if (likely(!vma || addr + len <= vma->vm_start)) { + /* + * Remember the place where we stopped the 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; + if (do_color_align) + addr = COLOUR_ALIGN(addr, pgoff); + } } unsigned long @@ -163,7 +190,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, unsigned long task_size = STACK_TOP32; unsigned long addr = addr0; int do_color_align; - struct vm_unmapped_area_info info; /* This should only ever run for 32-bit processes. */ BUG_ON(!test_thread_flag(TIF_32BIT)); @@ -198,27 +224,73 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } - info.flags = VM_UNMAPPED_AREA_TOPDOWN; - info.length = len; - info.low_limit = PAGE_SIZE; - info.high_limit = mm->mmap_base; - info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; - info.align_offset = pgoff << PAGE_SHIFT; - addr = vm_unmapped_area(&info); + /* 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; + if (do_color_align) { + unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff); + + addr = base + len; + } + /* make sure it can fit in the remaining address space */ + if (likely(addr > len)) { + vma = find_vma(mm, addr-len); + if (!vma || addr <= vma->vm_start) { + /* remember the address as a hint for next time */ + return (mm->free_area_cache = addr-len); + } + } + + if (unlikely(mm->mmap_base < len)) + goto bottomup; + + addr = mm->mmap_base-len; + if (do_color_align) + addr = COLOUR_ALIGN_DOWN(addr, pgoff); + + do { + /* + * Lookup failure means no vma is above this address, + * else if new region fits below vma->vm_start, + * return with success: + */ + vma = find_vma(mm, addr); + if (likely(!vma || addr+len <= vma->vm_start)) { + /* 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; + if (do_color_align) + addr = COLOUR_ALIGN_DOWN(addr, pgoff); + } while (likely(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. */ - if (addr & ~PAGE_MASK) { - VM_BUG_ON(addr != -ENOMEM); - info.flags = 0; - info.low_limit = TASK_UNMAPPED_BASE; - info.high_limit = STACK_TOP32; - addr = vm_unmapped_area(&info); - } + 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; } -- 2.39.2