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bootmem: factor out the marking of a PFN range
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Introduce new helpers that mark a range that resides completely on a node
or node-agnostic ranges that might also span node boundaries.

The free/reserve API functions will then directly use these helpers.

Note that the free/reserve semantics become more strict: while the prior
code took basically arbitrary range arguments and marked the PFNs that
happen to fall into that range, the new code requires node-specific ranges
to be completely on the node.  The node-agnostic requests might span node
boundaries as long as the nodes are contiguous.

Passing ranges that do not satisfy these criteria is a bug.

[akpm@linux-foundation.org: fix printk warnings]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Johannes Weiner authored and Linus Torvalds committed Jul 24, 2008
1 parent d747fa4 commit e2bf3ca
Showing 1 changed file with 69 additions and 119 deletions.
188 changes: 69 additions & 119 deletions mm/bootmem.c
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Original file line number Diff line number Diff line change
Expand Up @@ -234,6 +234,9 @@ static void __init __free(bootmem_data_t *bdata,
sidx + PFN_DOWN(bdata->node_boot_start),
eidx + PFN_DOWN(bdata->node_boot_start));

if (bdata->hint_idx > sidx)
bdata->hint_idx = sidx;

for (idx = sidx; idx < eidx; idx++)
if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
BUG();
Expand Down Expand Up @@ -263,40 +266,57 @@ static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
return 0;
}

static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
unsigned long size)
static int __init mark_bootmem_node(bootmem_data_t *bdata,
unsigned long start, unsigned long end,
int reserve, int flags)
{
unsigned long sidx, eidx;
unsigned long i;

BUG_ON(!size);
bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
bdata - bootmem_node_data, start, end, reserve, flags);

/* out range */
if (addr + size < bdata->node_boot_start ||
PFN_DOWN(addr) > bdata->node_low_pfn)
return;
/*
* round down end of usable mem, partially free pages are
* considered reserved.
*/
BUG_ON(start < PFN_DOWN(bdata->node_boot_start));
BUG_ON(end > bdata->node_low_pfn);

if (addr >= bdata->node_boot_start &&
PFN_DOWN(addr - bdata->node_boot_start) < bdata->hint_idx)
bdata->hint_idx = PFN_DOWN(addr - bdata->node_boot_start);
sidx = start - PFN_DOWN(bdata->node_boot_start);
eidx = end - PFN_DOWN(bdata->node_boot_start);

/*
* Round up to index to the range.
*/
if (PFN_UP(addr) > PFN_DOWN(bdata->node_boot_start))
sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
if (reserve)
return __reserve(bdata, sidx, eidx, flags);
else
sidx = 0;
__free(bdata, sidx, eidx);
return 0;
}

static int __init mark_bootmem(unsigned long start, unsigned long end,
int reserve, int flags)
{
unsigned long pos;
bootmem_data_t *bdata;

pos = start;
list_for_each_entry(bdata, &bdata_list, list) {
int err;
unsigned long max;

if (pos < PFN_DOWN(bdata->node_boot_start)) {
BUG_ON(pos != start);
continue;
}

max = min(bdata->node_low_pfn, end);

eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
err = mark_bootmem_node(bdata, pos, max, reserve, flags);
if (reserve && err) {
mark_bootmem(start, pos, 0, 0);
return err;
}

__free(bdata, sidx, eidx);
if (max == end)
return 0;
pos = bdata->node_low_pfn;
}
BUG();
}

/**
Expand All @@ -307,12 +327,17 @@ static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
*
* Partial pages will be considered reserved and left as they are.
*
* Only physical pages that actually reside on @pgdat are marked.
* The range must reside completely on the specified node.
*/
void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
unsigned long size)
{
free_bootmem_core(pgdat->bdata, physaddr, size);
unsigned long start, end;

start = PFN_UP(physaddr);
end = PFN_DOWN(physaddr + size);

mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
}

/**
Expand All @@ -322,83 +347,16 @@ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
*
* Partial pages will be considered reserved and left as they are.
*
* All physical pages within the range are marked, no matter what
* node they reside on.
* The range must be contiguous but may span node boundaries.
*/
void __init free_bootmem(unsigned long addr, unsigned long size)
{
bootmem_data_t *bdata;
list_for_each_entry(bdata, &bdata_list, list)
free_bootmem_core(bdata, addr, size);
}

/*
* Marks a particular physical memory range as unallocatable. Usable RAM
* might be used for boot-time allocations - or it might get added
* to the free page pool later on.
*/
static int __init can_reserve_bootmem_core(bootmem_data_t *bdata,
unsigned long addr, unsigned long size, int flags)
{
unsigned long sidx, eidx;
unsigned long i;

BUG_ON(!size);

/* out of range, don't hold other */
if (addr + size < bdata->node_boot_start ||
PFN_DOWN(addr) > bdata->node_low_pfn)
return 0;

/*
* Round up to index to the range.
*/
if (addr > bdata->node_boot_start)
sidx= PFN_DOWN(addr - bdata->node_boot_start);
else
sidx = 0;

eidx = PFN_UP(addr + size - bdata->node_boot_start);
if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);

for (i = sidx; i < eidx; i++) {
if (test_bit(i, bdata->node_bootmem_map)) {
if (flags & BOOTMEM_EXCLUSIVE)
return -EBUSY;
}
}

return 0;

}

static void __init reserve_bootmem_core(bootmem_data_t *bdata,
unsigned long addr, unsigned long size, int flags)
{
unsigned long sidx, eidx;
unsigned long i;

BUG_ON(!size);

/* out of range */
if (addr + size < bdata->node_boot_start ||
PFN_DOWN(addr) > bdata->node_low_pfn)
return;

/*
* Round up to index to the range.
*/
if (addr > bdata->node_boot_start)
sidx= PFN_DOWN(addr - bdata->node_boot_start);
else
sidx = 0;
unsigned long start, end;

eidx = PFN_UP(addr + size - bdata->node_boot_start);
if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
start = PFN_UP(addr);
end = PFN_DOWN(addr + size);

return __reserve(bdata, sidx, eidx, flags);
mark_bootmem(start, end, 0, 0);
}

/**
Expand All @@ -410,18 +368,17 @@ static void __init reserve_bootmem_core(bootmem_data_t *bdata,
*
* Partial pages will be reserved.
*
* Only physical pages that actually reside on @pgdat are marked.
* The range must reside completely on the specified node.
*/
int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
unsigned long size, int flags)
{
int ret;
unsigned long start, end;

ret = can_reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
if (ret < 0)
return -ENOMEM;
reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
return 0;
start = PFN_DOWN(physaddr);
end = PFN_UP(physaddr + size);

return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
}

#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
Expand All @@ -433,24 +390,17 @@ int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
*
* Partial pages will be reserved.
*
* All physical pages within the range are marked, no matter what
* node they reside on.
* The range must be contiguous but may span node boundaries.
*/
int __init reserve_bootmem(unsigned long addr, unsigned long size,
int flags)
{
bootmem_data_t *bdata;
int ret;
unsigned long start, end;

list_for_each_entry(bdata, &bdata_list, list) {
ret = can_reserve_bootmem_core(bdata, addr, size, flags);
if (ret < 0)
return ret;
}
list_for_each_entry(bdata, &bdata_list, list)
reserve_bootmem_core(bdata, addr, size, flags);
start = PFN_DOWN(addr);
end = PFN_UP(addr + size);

return 0;
return mark_bootmem(start, end, 1, flags);
}
#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */

Expand Down Expand Up @@ -663,7 +613,7 @@ void * __init alloc_bootmem_section(unsigned long size,
if (start_nr != section_nr || end_nr != section_nr) {
printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
section_nr);
free_bootmem_core(pgdat->bdata, __pa(ptr), size);
free_bootmem_node(pgdat, __pa(ptr), size);
ptr = NULL;
}

Expand Down

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