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authorBernhard Walle <bwalle@suse.de>2008-02-07 00:15:17 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:25 -0800
commit72a7fe3967dbf86cb34e24fbf1d957fe24d2f246 (patch)
treec19f7d0b530577359840e959cce204939caf0649 /mm/bootmem.c
parent25fad945a7f7ff2cf06e437381c6a1121784dbd9 (diff)
downloadlwn-72a7fe3967dbf86cb34e24fbf1d957fe24d2f246.tar.gz
lwn-72a7fe3967dbf86cb34e24fbf1d957fe24d2f246.zip
Introduce flags for reserve_bootmem()
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>
Diffstat (limited to 'mm/bootmem.c')
-rw-r--r--mm/bootmem.c27
1 files changed, 21 insertions, 6 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 00a96970b237..f6ff4337b424 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -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 */