On Fri, Jul 26, 2013 at 07:42:39PM +0800, Jingbai Ma wrote: > Hi, > > I have run some tests with makedumpfile 1.5.4 and upstream kernel > 3.11-rc2+ on a machine with 4TB memory, here is testing results: > > Test environment: > Machine: HP ProLiant DL980 G7 with 4TB RAM. > CPU: Intel(R) Xeon(R) CPU E7- 2860 @ 2.27GHz (8 sockets, 10 cores) > (Only 1 CPU was enabled the 2nd kernel) > Kernel: 3.11.0-rc2+ (at patch b3a3a9c441e2c8f6b6760de9331023a7906a4ac6) > crashkernel=384MB > vmcore size: 4.0TB > Dump file size: 15GB > All measured time from debug message of makedumpfile. > As a comparison, I also have tested makedumpfile 1.5.3. > > (all time in seconds) > Excluding pages Copy data Total > makedumpfile 1.5.3 468 1182 1650 > makedumpfile 1.5.4 93 518 611 > > > So it seems there is a great performance improvement by the mmap mechanism. [CC Andrew]. Thanks Jingbai for testing results. Good to see that vmcore mmap() patches are helping. Thanks Vivek
