Programming

I do some try on one application to know how to fasten a application

root@localhost:/tmpfs> ./pbzip2 -p2 -f -k libc5.cvs.tar
Average Time:22.578 Min Time:22.542 Max Time:22.594

First: I need to say my setting:
using tmpfs: mount -t tmpfs -o size=200m,nr_inodes=10k,mode=777 tmpfs /tmpfs
all the application need to run is located in tmpfs



I do some try below:
1. compile the pbzip2 with -o3,---->can't improve obviously
2. stop some service----- can't improve obviously
3.nice -5 (or more than5 ) ./pbzip2 -p2 -f -k libc5.cvs.tar can't improve obviously

Is there some other method ???

There is such a thing as tuning a filesystem. I have no idea what OS you are running, but there are tools available to improve I/O (filesystem thoughput) -- I think you may be limited by I/O.

You can try running vmstat during a pbzip2 test to see what is happening. Try man vmstat for more information.

If your system has enough RAM there is probably no point running it in a RAMdisk, UNIX does caching in RAM for you.

It's possible you could improve on -O3 actually. There's some obscure options like -ftree-vectorize in the newer versions of gcc that aren't enabled by default because they are experimental.