On Mon, Dec 15, 2003 at 06:39:35PM +0200, Shachar Shemesh wrote: > Hi list,
Hi Shachar, good questions! I'm curious what others will answer. Here are some comments from me. > In one case, the fast distro is RedHat 7.2, and the slow one is 9. In > another I'm not sure what the fast one is, but the slow on is AS 3. I > suspect that RedHat screwed something up with their newer kernels > (perhaps something incorrectly backported from 2.6?). Why do you suspect the kernel? is the operation that's slower kernel bound? for example, there was an issue with RH's use of UTF-8 as default in RH9, IIRC, that caused e.g. grep to be much slower. > So far, I have seen neither computers myself, and I only had chance to > do repetitive "try this, what now?" with one of them over the phone. The > problem is that nothing shows problems! The tasks seem almost unrelated. > In one case it's copying stuff over the net to another computer (1:2 > performance ratio), in another it's running ./configure (1:4 ratio). In > both cases, there does not appear to be any clear-cut curlpit. In one > case I asked the client to try out the 7.2 kernel with the 8 > distribution, but I don't have the results in yet. Ok, that's more interesting. For the network case, packet dumps on both sides of the connections would be interesting. For the configure, might it be gcc 2.96 vs. gcc 3.2.x? > The questions: > a. Does anyone have a recommended benchmarking tool? I found this page > (http://lbs.sourceforge.net/), but I'd really rather not start messing > around with each and every one of those until I find the one I like. If > anyone here has prior experience, I'd love it if you could share. I don't like "whole world" benchmarks - I prefer benchmarks that allow you to measure one area specifically. For a general benchmark, I use - what else - a kernel compilation. > b. Occasionally, I get a system that responds "slow", but aside from a > high load average, there seems to be nothing wrong with it. CPU is idle > most of the time, etc. Any ideas how I can find out what and why is > going on? profiling the system with e.g. oprofile is a good start - it will tell you where your kernel + application are spending most of their time, by function. Cheers, Muli -- Muli Ben-Yehuda http://www.mulix.org | http://mulix.livejournal.com/ "the nucleus of linux oscillates my world" - [EMAIL PROTECTED]
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