![Yasunori Goto](/assets/img/avatar_default.png)
This introduces a limit parameter to the core bootmem allocator; The new parameter indicates that physical memory allocated by the bootmem allocator should be within the requested limit. We also introduce alloc_bootmem_low_pages_limit, alloc_bootmem_node_limit, alloc_bootmem_low_pages_node_limit apis, but alloc_bootmem_low_pages_limit is the only api used for swiotlb. The existing alloc_bootmem_low_pages() api could instead have been changed and made to pass right limit to the core allocator. But that would make the patch more intrusive for 2.6.14, as other arches use alloc_bootmem_low_pages(). We may be done that post 2.6.14 as a cleanup. With this, swiotlb gets memory within 4G for both x86_64 and ia64 arches. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Ravikiran G Thirumalai <kiran@scalex86.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
425 lines
11 KiB
C
425 lines
11 KiB
C
/*
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* linux/mm/bootmem.c
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*
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* Copyright (C) 1999 Ingo Molnar
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* Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
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*
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* simple boot-time physical memory area allocator and
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* free memory collector. It's used to deal with reserved
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* system memory and memory holes as well.
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*/
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#include <linux/mm.h>
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#include <linux/kernel_stat.h>
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#include <linux/swap.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/mmzone.h>
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#include <linux/module.h>
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#include <asm/dma.h>
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#include <asm/io.h>
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#include "internal.h"
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/*
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* Access to this subsystem has to be serialized externally. (this is
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* true for the boot process anyway)
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*/
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unsigned long max_low_pfn;
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unsigned long min_low_pfn;
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unsigned long max_pfn;
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EXPORT_SYMBOL(max_pfn); /* This is exported so
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* dma_get_required_mask(), which uses
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* it, can be an inline function */
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#ifdef CONFIG_CRASH_DUMP
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/*
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* If we have booted due to a crash, max_pfn will be a very low value. We need
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* to know the amount of memory that the previous kernel used.
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*/
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unsigned long saved_max_pfn;
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#endif
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/* return the number of _pages_ that will be allocated for the boot bitmap */
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unsigned long __init bootmem_bootmap_pages (unsigned long pages)
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{
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unsigned long mapsize;
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mapsize = (pages+7)/8;
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mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK;
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mapsize >>= PAGE_SHIFT;
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return mapsize;
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}
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/*
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* Called once to set up the allocator itself.
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*/
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static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
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unsigned long mapstart, unsigned long start, unsigned long end)
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{
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bootmem_data_t *bdata = pgdat->bdata;
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unsigned long mapsize = ((end - start)+7)/8;
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pgdat->pgdat_next = pgdat_list;
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pgdat_list = pgdat;
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mapsize = ALIGN(mapsize, sizeof(long));
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bdata->node_bootmem_map = phys_to_virt(mapstart << PAGE_SHIFT);
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bdata->node_boot_start = (start << PAGE_SHIFT);
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bdata->node_low_pfn = end;
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/*
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* Initially all pages are reserved - setup_arch() has to
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* register free RAM areas explicitly.
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*/
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memset(bdata->node_bootmem_map, 0xff, mapsize);
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return mapsize;
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}
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/*
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* Marks a particular physical memory range as unallocatable. Usable RAM
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* might be used for boot-time allocations - or it might get added
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* to the free page pool later on.
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*/
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static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size)
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{
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unsigned long i;
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/*
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* round up, partially reserved pages are considered
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* fully reserved.
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*/
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unsigned long sidx = (addr - bdata->node_boot_start)/PAGE_SIZE;
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unsigned long eidx = (addr + size - bdata->node_boot_start +
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PAGE_SIZE-1)/PAGE_SIZE;
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unsigned long end = (addr + size + PAGE_SIZE-1)/PAGE_SIZE;
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BUG_ON(!size);
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BUG_ON(sidx >= eidx);
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BUG_ON((addr >> PAGE_SHIFT) >= bdata->node_low_pfn);
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BUG_ON(end > bdata->node_low_pfn);
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for (i = sidx; i < eidx; i++)
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if (test_and_set_bit(i, bdata->node_bootmem_map)) {
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#ifdef CONFIG_DEBUG_BOOTMEM
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printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
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#endif
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}
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}
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static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size)
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{
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unsigned long i;
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unsigned long start;
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/*
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* round down end of usable mem, partially free pages are
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* considered reserved.
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*/
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unsigned long sidx;
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unsigned long eidx = (addr + size - bdata->node_boot_start)/PAGE_SIZE;
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unsigned long end = (addr + size)/PAGE_SIZE;
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BUG_ON(!size);
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BUG_ON(end > bdata->node_low_pfn);
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if (addr < bdata->last_success)
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bdata->last_success = addr;
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/*
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* Round up the beginning of the address.
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*/
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start = (addr + PAGE_SIZE-1) / PAGE_SIZE;
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sidx = start - (bdata->node_boot_start/PAGE_SIZE);
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for (i = sidx; i < eidx; i++) {
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if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
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BUG();
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}
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}
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/*
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* We 'merge' subsequent allocations to save space. We might 'lose'
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* some fraction of a page if allocations cannot be satisfied due to
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* size constraints on boxes where there is physical RAM space
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* fragmentation - in these cases (mostly large memory boxes) this
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* is not a problem.
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*
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* On low memory boxes we get it right in 100% of the cases.
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*
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* alignment has to be a power of 2 value.
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*
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* NOTE: This function is _not_ reentrant.
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*/
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static void * __init
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__alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
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unsigned long align, unsigned long goal, unsigned long limit)
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{
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unsigned long offset, remaining_size, areasize, preferred;
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unsigned long i, start = 0, incr, eidx, end_pfn = bdata->node_low_pfn;
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void *ret;
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if(!size) {
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printk("__alloc_bootmem_core(): zero-sized request\n");
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BUG();
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}
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BUG_ON(align & (align-1));
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if (limit && bdata->node_boot_start >= limit)
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return NULL;
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limit >>=PAGE_SHIFT;
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if (limit && end_pfn > limit)
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end_pfn = limit;
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eidx = end_pfn - (bdata->node_boot_start >> PAGE_SHIFT);
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offset = 0;
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if (align &&
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(bdata->node_boot_start & (align - 1UL)) != 0)
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offset = (align - (bdata->node_boot_start & (align - 1UL)));
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offset >>= PAGE_SHIFT;
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/*
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* We try to allocate bootmem pages above 'goal'
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* first, then we try to allocate lower pages.
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*/
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if (goal && (goal >= bdata->node_boot_start) &&
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((goal >> PAGE_SHIFT) < end_pfn)) {
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preferred = goal - bdata->node_boot_start;
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if (bdata->last_success >= preferred)
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if (!limit || (limit && limit > bdata->last_success))
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preferred = bdata->last_success;
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} else
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preferred = 0;
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preferred = ALIGN(preferred, align) >> PAGE_SHIFT;
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preferred += offset;
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areasize = (size+PAGE_SIZE-1)/PAGE_SIZE;
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incr = align >> PAGE_SHIFT ? : 1;
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restart_scan:
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for (i = preferred; i < eidx; i += incr) {
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unsigned long j;
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i = find_next_zero_bit(bdata->node_bootmem_map, eidx, i);
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i = ALIGN(i, incr);
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if (test_bit(i, bdata->node_bootmem_map))
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continue;
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for (j = i + 1; j < i + areasize; ++j) {
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if (j >= eidx)
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goto fail_block;
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if (test_bit (j, bdata->node_bootmem_map))
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goto fail_block;
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}
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start = i;
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goto found;
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fail_block:
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i = ALIGN(j, incr);
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}
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if (preferred > offset) {
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preferred = offset;
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goto restart_scan;
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}
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return NULL;
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found:
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bdata->last_success = start << PAGE_SHIFT;
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BUG_ON(start >= eidx);
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/*
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* Is the next page of the previous allocation-end the start
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* of this allocation's buffer? If yes then we can 'merge'
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* the previous partial page with this allocation.
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*/
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if (align < PAGE_SIZE &&
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bdata->last_offset && bdata->last_pos+1 == start) {
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offset = ALIGN(bdata->last_offset, align);
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BUG_ON(offset > PAGE_SIZE);
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remaining_size = PAGE_SIZE-offset;
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if (size < remaining_size) {
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areasize = 0;
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/* last_pos unchanged */
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bdata->last_offset = offset+size;
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ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset +
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bdata->node_boot_start);
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} else {
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remaining_size = size - remaining_size;
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areasize = (remaining_size+PAGE_SIZE-1)/PAGE_SIZE;
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ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset +
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bdata->node_boot_start);
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bdata->last_pos = start+areasize-1;
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bdata->last_offset = remaining_size;
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}
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bdata->last_offset &= ~PAGE_MASK;
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} else {
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bdata->last_pos = start + areasize - 1;
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bdata->last_offset = size & ~PAGE_MASK;
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ret = phys_to_virt(start * PAGE_SIZE + bdata->node_boot_start);
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}
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/*
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* Reserve the area now:
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*/
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for (i = start; i < start+areasize; i++)
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if (unlikely(test_and_set_bit(i, bdata->node_bootmem_map)))
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BUG();
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memset(ret, 0, size);
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return ret;
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}
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static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
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{
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struct page *page;
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unsigned long pfn;
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bootmem_data_t *bdata = pgdat->bdata;
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unsigned long i, count, total = 0;
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unsigned long idx;
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unsigned long *map;
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int gofast = 0;
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BUG_ON(!bdata->node_bootmem_map);
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count = 0;
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/* first extant page of the node */
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pfn = bdata->node_boot_start >> PAGE_SHIFT;
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idx = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT);
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map = bdata->node_bootmem_map;
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/* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */
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if (bdata->node_boot_start == 0 ||
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ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG))
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gofast = 1;
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for (i = 0; i < idx; ) {
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unsigned long v = ~map[i / BITS_PER_LONG];
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if (gofast && v == ~0UL) {
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int j, order;
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page = pfn_to_page(pfn);
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count += BITS_PER_LONG;
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__ClearPageReserved(page);
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order = ffs(BITS_PER_LONG) - 1;
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set_page_refs(page, order);
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for (j = 1; j < BITS_PER_LONG; j++) {
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if (j + 16 < BITS_PER_LONG)
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prefetchw(page + j + 16);
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__ClearPageReserved(page + j);
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}
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__free_pages(page, order);
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i += BITS_PER_LONG;
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page += BITS_PER_LONG;
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} else if (v) {
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unsigned long m;
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page = pfn_to_page(pfn);
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for (m = 1; m && i < idx; m<<=1, page++, i++) {
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if (v & m) {
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count++;
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__ClearPageReserved(page);
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set_page_refs(page, 0);
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__free_page(page);
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}
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}
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} else {
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i+=BITS_PER_LONG;
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}
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pfn += BITS_PER_LONG;
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}
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total += count;
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/*
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* Now free the allocator bitmap itself, it's not
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* needed anymore:
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*/
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page = virt_to_page(bdata->node_bootmem_map);
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count = 0;
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for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
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count++;
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__ClearPageReserved(page);
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set_page_count(page, 1);
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__free_page(page);
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}
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total += count;
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bdata->node_bootmem_map = NULL;
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return total;
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}
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unsigned long __init init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn)
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{
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return(init_bootmem_core(pgdat, freepfn, startpfn, endpfn));
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}
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void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size)
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{
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reserve_bootmem_core(pgdat->bdata, physaddr, size);
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}
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void __init free_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size)
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{
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free_bootmem_core(pgdat->bdata, physaddr, size);
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}
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unsigned long __init free_all_bootmem_node (pg_data_t *pgdat)
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{
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return(free_all_bootmem_core(pgdat));
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}
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unsigned long __init init_bootmem (unsigned long start, unsigned long pages)
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{
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max_low_pfn = pages;
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min_low_pfn = start;
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return(init_bootmem_core(NODE_DATA(0), start, 0, pages));
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}
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#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
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void __init reserve_bootmem (unsigned long addr, unsigned long size)
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{
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reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size);
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}
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#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
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void __init free_bootmem (unsigned long addr, unsigned long size)
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{
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free_bootmem_core(NODE_DATA(0)->bdata, addr, size);
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}
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unsigned long __init free_all_bootmem (void)
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{
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return(free_all_bootmem_core(NODE_DATA(0)));
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}
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void * __init __alloc_bootmem_limit (unsigned long size, unsigned long align, unsigned long goal,
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unsigned long limit)
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{
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pg_data_t *pgdat = pgdat_list;
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void *ptr;
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for_each_pgdat(pgdat)
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if ((ptr = __alloc_bootmem_core(pgdat->bdata, size,
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align, goal, limit)))
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return(ptr);
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/*
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* Whoops, we cannot satisfy the allocation request.
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*/
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printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
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panic("Out of memory");
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return NULL;
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}
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void * __init __alloc_bootmem_node_limit (pg_data_t *pgdat, unsigned long size, unsigned long align,
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unsigned long goal, unsigned long limit)
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{
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void *ptr;
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ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal, limit);
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if (ptr)
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return (ptr);
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return __alloc_bootmem_limit(size, align, goal, limit);
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}
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