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Introduce flags for reserve_bootmem()

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This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Bernhard Walle
2008-02-07 00:15:17 -08:00
committed by Linus Torvalds
parent 25fad945a7
commit 72a7fe3967
43 changed files with 183 additions and 105 deletions
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27
mm/bootmem.c
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@@ -111,11 +111,12 @@ static unsigned long __init init_bootmem_core(pg_data_t *pgdat,
* might be used for boot-time allocations - or it might get added
* to the free page pool later on.
*/
static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
unsigned long size)
static int __init reserve_bootmem_core(bootmem_data_t *bdata,
unsigned long addr, unsigned long size, int flags)
{
unsigned long sidx, eidx;
unsigned long i;
int ret;
/*
* round up, partially reserved pages are considered
@@ -133,7 +134,20 @@ static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long add
#ifdef CONFIG_DEBUG_BOOTMEM
printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
#endif
if (flags & BOOTMEM_EXCLUSIVE) {
ret = -EBUSY;
goto err;
}
}
return 0;
err:
/* unreserve memory we accidentally reserved */
for (i--; i >= sidx; i--)
clear_bit(i, bdata->node_bootmem_map);
return ret;
}
static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
@@ -374,9 +388,9 @@ unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
}
void __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
unsigned long size)
unsigned long size, int flags)
{
reserve_bootmem_core(pgdat->bdata, physaddr, size);
reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
}
void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
@@ -398,9 +412,10 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
}
#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
void __init reserve_bootmem(unsigned long addr, unsigned long size)
int __init reserve_bootmem(unsigned long addr, unsigned long size,
int flags)
{
reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size);
return reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size, flags);
}
#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */