Messages in this thread |  | | Subject | Re: updated: ext3 IO latency measurements on v2.6.30-rc1 | Date | Mon, 18 May 2009 12:37:19 -0400 | From | Sanjoy Mahajan <> |
| |
To test the ext3 improvements in 2.6.30-rc5, I tried my previous test of starting an rxvt while findutils or 'aptitude dist-upgrade' is madly spinning the disk.
With vanilla 2.6.29 in those circumstances, starting an rxvt took 4 seconds on an otherwise unloaded system (Thinkpad T60 w/ 1.83GHz dual-core CPU, 1.5GB RAM, 5400 rpm drive). The second rxvt came up right away. So the first rxvt probably stalled until /usr/bin/rxvt could be grabbed from disk.
With 2.6.30-rc5, the rxvt showed up much faster -- either right away (maybe it was still in the cache) or after about 0.5 seconds (probably the uncached case).
Other tests were also snappy, like opening a 10MB PDF file in Emacs, adding a newline at the beginning, and saving it (while findutils was running). I hadn't done the same test with 2.6.29, but I'm pretty sure it would have been painfully slow if findutils was running.
So, relative to 2.6.29, I see a large improvement in interactive behavior under high IO load.
-Sanjoy
`Until lions have their historians, tales of the hunt shall always glorify the hunters.' --African Proverb
|  |