Comment 326 for bug 620074

Hi guys,

I have run my test script, which I ran with previous kernels. There is a pretty big increase in performance. on 2.6.30-rc3. The BIGGEST difference I noticed, about my test output was that vmstat reported large numbers (10) of "uninterruptible sleep" processes. Now, it's down to about 1-4.

I saw some 9 and 10 second fsync latencies, but most were around 0.3 seconds, with some around 1-2 seconds.

However, I don't think the kernel is back to what it used to be yet. I never used to have problems with ext3 fsync latencies at all. It used to be that a simple file copy would not cause much latency issues on the responsiveness of my regular apps. In fact, generally speaking, I never noticed any problems when copying huge files. Now, when copying large files, I still get some choppiness, even with Ted's patches.

I'm wondering if the real problem lies in the block io layer, and not the file system layer?