diff options
| author | Bernhard Walle <bwalle@suse.de> | 2008-02-07 00:15:17 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-07 08:42:25 -0800 |
| commit | 72a7fe3967dbf86cb34e24fbf1d957fe24d2f246 (patch) | |
| tree | c19f7d0b530577359840e959cce204939caf0649 /mm/bootmem.c | |
| parent | 25fad945a7f7ff2cf06e437381c6a1121784dbd9 (diff) | |
| download | lwn-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.c | 27 |
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 */ |