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| author | Jianguo Wu <wujianguo@huawei.com> | 2012-09-17 14:08:56 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-09-17 15:00:37 -0700 |
| commit | 05cf96398e1b6502f9e191291b715c7463c9d5dd (patch) | |
| tree | 8dd12c4142216f4e3acb344146c0c4cae3a1588f /include/linux/memory.h | |
| parent | 18b48d5873a6fc8e0e6044ddb572fcda26988f19 (diff) | |
| download | lwn-05cf96398e1b6502f9e191291b715c7463c9d5dd.tar.gz lwn-05cf96398e1b6502f9e191291b715c7463c9d5dd.zip | |
mm/ia64: fix a memory block size bug
I found following definition in include/linux/memory.h, in my IA64
platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE
will be 0.
#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
Because MIN_MEMORY_BLOCK_SIZE is int type and length of 32bits,
so MIN_MEMORY_BLOCK_SIZE(1 << 32) will will equal to 0.
Actually when SECTION_SIZE_BITS >= 31, MIN_MEMORY_BLOCK_SIZE will be wrong.
This will cause wrong system memory infomation in sysfs.
I think it should be:
#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
And "echo offline > memory0/state" will cause following call trace:
kernel BUG at mm/memory_hotplug.c:885!
sh[6455]: bugcheck! 0 [1]
Pid: 6455, CPU 0, comm: sh
psr : 0000101008526030 ifs : 8000000000000fa4 ip : [<a0000001008c40f0>] Not tainted (3.6.0-rc1)
ip is at offline_pages+0x210/0xee0
Call Trace:
show_stack+0x80/0xa0
show_regs+0x640/0x920
die+0x190/0x2c0
die_if_kernel+0x50/0x80
ia64_bad_break+0x3d0/0x6e0
ia64_native_leave_kernel+0x0/0x270
offline_pages+0x210/0xee0
alloc_pages_current+0x180/0x2a0
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/memory.h')
| -rw-r--r-- | include/linux/memory.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/memory.h b/include/linux/memory.h index 1ac7f6e405f9..ff9a9f8e0ed9 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -19,7 +19,7 @@ #include <linux/compiler.h> #include <linux/mutex.h> -#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) +#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) struct memory_block { unsigned long start_section_nr; |