From: sichiwai (Christian.M.Iwainsky_at_informatik.stud.uni-erlangen.de)
Date: Thu Mar 16 2006 - 17:36:52 PST
Hello, I did some performance measurements of the time that blcr takes to complete a checkpoint and compared it to the time a programm needs to write the same amount of data from memory to the harddrive. The same behaviour can reproduced and can be observed on multiple runs. I measured on a Intel(R) Xeon(TM) CPU 2.66GHz with 2Gig of RAM. When I plotted the performance of BLCR, I discovered "erratic" behaviour from 700 to 900 megabytes of checkpoint data. As you stated in your papers, blcr performance drops when approximately half of the memory of the machine is used, due to the VMADump. Maybe you have some insight what might cause this behaviour? I attached the graph as an PDF. The X-Axis is the amount of data to checkpoint/write and the Y-Axis is the time the program took to checkpoint/write the data to local storage. (Sorry for german labels) Greetings Christian