Hi... > However for my testings, the performances are about the same regardless if > the system has more memory (larger than the file size) or not. I can't quite > understand this. Can anyone help me with this? I'm using kernel 2.6.18. It will be a quite long answer if you need details. In essence, it entirely depends on how you did the test, what background processes that run, your L1/L2 cache size, the effective page cache replacement algorithm and so on. One thing that has great impact is the way you read the file. How did you do it? sequentially? or read N kilobytes then skip M kilobytes? backward? Also, don't forget about the I/O scheduler you currently use... it may have impact on certain degree. To give you a view on how complicated the I/O test regarding this issue, take a look on my article: http://www.samag.com/documents/s=10101/sam0616a/0616a.htm Actually it talks about Fengguang Wu's Adaptive Read-ahead, but generally it also cover about file I/O operation in Linux. I'm sorry if my answer doesn't really clear your doubt.... regards, Mulyadi. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
