On a system with large amount of memory (256GB), invoking page-types can
take quite a long time, which is unreasonable considering the user only
wants a description of the flags:
# time ./page-types -d 0x10
0x0000000000000010 ____D_____________________________ dirty
real 0m34.285s
user 0m1.966s
sys 0m32.313s
This is because we still walk the entire address range.
Exiting early seems like a reasonble solution:
# time ./page-types -d 0x10
0x0000000000000010 ____D_____________________________ dirty
real 0m0.007s
user 0m0.001s
sys 0m0.005s
Signed-off-by: Alex Chiang <achiang@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Haicheng Li <haicheng.li@intel.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bb86a7338b