makedumpfile mmap() benchmark

[Jingbai Ma]

Hi,

I have tested the makedumpfile mmap patch on a machine with 2TB memory, 
here is testing results:
Test environment:
Machine: HP ProLiant DL980 G7 with 2TB RAM.
CPU: Intel(R) Xeon(R) CPU E7- 2860  @ 2.27GHz (8 sockets, 10 cores)
(Only 1 cpu was enabled the 2nd kernel)
Kernel: 3.9.0-rc3+ with mmap kernel patch v3
vmcore size: 2.0TB
Dump file size: 3.6GB
makedumpfile mmap branch with parameters: -c --message-level 23 -d 31 
--map-size <map-size>
All measured time from debug message of makedumpfile.

As a comparison, I also have tested with original kernel and original 
makedumpfile 1.5.1 and 1.5.3.
I added all [Excluding unnecessary pages] and [Excluding free pages] 
time together as "Filter Pages", and [Copyying Data] as "Copy data" here.

makedumjpfile	Kernel	map-size (KB)	Filter pages (s)	Copy data (s)	Total (s)
1.5.1	 3.7.0-0.36.el7.x86_64	N/A	940.28	1269.25	2209.53
1.5.3	 3.7.0-0.36.el7.x86_64	N/A	380.09	992.77	1372.86
1.5.3	v3.9-rc3	N/A	197.77	892.27	1090.04
1.5.3+mmap	v3.9-rc3+mmap	0	164.87	606.06	770.93
1.5.3+mmap	v3.9-rc3+mmap	4	88.62	576.07	664.69
1.5.3+mmap	v3.9-rc3+mmap	1024	83.66	477.23	560.89
1.5.3+mmap	v3.9-rc3+mmap	2048	83.44	477.21	560.65
1.5.3+mmap	v3.9-rc3+mmap	10240	83.84	476.56	560.4


Thanks,
Jingbai Ma