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
