Hi Samuel, Thank you for feedback! On Sun, Aug 4, 2013 at 10:10 PM, Samuel J. Greear <[email protected]> wrote:
> Regarding the performance chart and testing so far, it's nice to know that > the cpu overhead is well-bounded and these small tests likely worked well > for simply making sure everything worked, but I wouldn't spend much/any > time on this type of testing going forward, since these microbenchmarks > only show cached performance -- the compressed numbers will basically > always look like a net loss here (albeit it looks like a small one, which > is good) -- the real numbers of interest are going to be performance of > uncached benchmarks / benchmarks that cause a lot of real disk i/o. As you > make it stable I would move onto things like fsstress, blogbench, bonnie, > etc. > Regarding the microbenchmarks, I tried to reduce the effect of caching by reloading hammer2 module between each write/read test, so it should only take place on HAMMER partition, but not on HAMMER2. I'll definitely do heavy I/O tests in the future. > If the code is stable enough I would be interested to hear what the > performance delta is between a pair of dd if=/dev/zero bs=64k count=5000 or > similar (as long as its much bigger than RAM) with zero-compression on vs > off. In theory it should look similar to the delta between cached io and > uncached io. > OK, I'm putting this test into my TODO list. Thank you. Daniel
