On Tue, 15 May 2001, T. Weyergraf wrote: > Reworked is good - it's rather a total rewrite ;-) The VM is one of my > suspects, but > I also question the new scheduling policies. > As all UP2000's being EV-67 ( or 68 ), mine is a EV-67, 667Mhz and 2Mbytes L2. > The system comes with 1.5Gig RAM, which should ( and does ) ensure, that swap > isn't reached.
True, but I've seen stranger things happen :-) > Good, i'll try that. I obviously have CONFIG_RTC set. On that issue: It used > to be the > case, that the Alphas encountered clock-skews without that option set in > earlier 2.2 kernels, > that could be overcome by setting RTC. Is that resolved ? Having the correct > time is > quite critical in my setup ( time-based services running across several NFS > exports ). I would recommend running an NTP daemon or something to sync the time on all of your servers on boot and periodically rather than relying on the RTC. It tends to be more reliable when you're dealing with multiple servers anyway (rather than having to set time that's fairly close on multiple machines by hand). > It's 3 adaptecs in there, plus one 3COM networking card ( 905B ). I've > seperately ran > tests on all harddrives, using bonnie, hdparm and my own stuff. All results > indicated no > difference in drive performance and associated CPU consumption. All disks are > in fact > SCSI disks. I had one IDE drive with an SCSI-to-IDE adaptor being connected > to it;s > own adaptec ( since it can't do TCQ ), but that was completely disabled > during the tests. > I am aware, that there is a completely new aic driver in 2.4.4, which gave > the reason > to test disk performance. > I do like the fact, that the new driver is apparently able to determine the > optimum TCQ depth > during run-time. However, i prefer to set things via boot-parameters. Anybody > ever > figured out, how to do that with the new driver ? I haven't looked at it too hard yet. I personally like the old driver better, but that's only because I'm more familiar with it code-wise :-P Was there much net traffic when you ran the tests or was the 3Com mostly inactive? > On the issue of the performance difference, i have had tests, that measure > process CPU > consumption with both, times(2) and getrusage(2). The ones with getrusage(2) > show > strange behaviour, by giving user-times on kernel 2.2.19, that are > questionable. > > Has anybody ever found evidence, that getrusage() reports strange user-times ? > The most bizarre thing is, that real- as well as system time seem OK, as well > as times(2) times ;-) Not yet. I'll see if I can free up some time to look at it more in-depth. Sounds like you definitely have a strange case, though. Perhaps I'll run some tests on my UP2k at work over the coming weekend and see if I get similar results. C
