Hi Guillaume Thanks for the explanation. When you compare that to "top" I must say that my top (part of procps 3.2.8) /does/ deliver values on the first shot. Even with "top -d 3600".
Unfortunately "-o" doesn't help in my case (to make a long story short: I'm collecting performance data - and no value means even just that (0.0 != "")). Regards, uwe --- Uwe Maier HP Software phone +49 7031 14 3814 fax +49 7031 14 6831 Schickardstrasse 25 ASM-SMS B32 3M11 71034 Boeblingen Germany > -----Original Message----- > From: Guillaume Chazarain [mailto:[email protected]] > Sent: Montag, 14. März 2011 02:49 > To: [email protected] > Subject: Bug#614978: iotop: All values 0.0 when using -b parameter > > iotop's scraping loop looks like: > > read_counters() > while running: > read_counters() > print delta > sleep(delay) > > So there are indeed two reads close to each other at startup. > You can see the first read in > http://repo.or.cz/w/iotop.git/blob/HEAD:/iotop/data.py#l372: > > 372 # A first time as we are interested in the delta > 373 self.update_process_counts() > > The first screen of output will be all zero or not depending on the > relative speed of iotop and the I/O generating process. So, all bets > are off. > > This is to mimic "top -d<huge value>" which gives you an output right > away and _then_ starts the main loop. > > There's always "iotop -o" to filter out zero values, so I don't know > if there's anything to fix here. > > -- > Guillaume >
