Ged Haywood wrote: > Hi there, > > On Fri, 12 Sep 2003, Rafael Garcia-Suarez wrote: > > > we're porting on AIX (4.3.3 and 5.2.0). The AIX boxes are > > supposed to be more powerful than their Linux equivalents, > > however the application is strangely slow on AIX > > You don't give much to go on. Are they really more powerful? > > What does 'powerful' mean anyway? What discs do you have and what > interfaces do they use, how much memory, what processors, speeds, how > many mod_perl processes, how big are they, are you getting into swap, > etc...?
Well, it's difficult to compare very different hardware, but basically the AIX boxen have SCSI discs, more memory, etc. and they're a lot more expensive ;-) > Have you benchmarked some simple things on the boxes? Benchmarking simple CPU-intensive perl scripts shows that they tend to be consistently slower in user time on AIX. Moreover if I survey CPU/memory usage on Linux and AIX (resp. with top and vmstat / w) I see that the application doesn't swap memory and that the load averages remains < 0.10. > > So I'm asking for the common wisdom about performance issues on AIX. > > I don't know anything worth writing about AIX but I'd look a little > deeper into what you're doing before you start blaming the OS. > > > Currently the perl I use is built with gcc and default > > settings. Should I set -Dusemymalloc=y ? Should I use the xlC or > > vac compilers ? Should I port everything to mod_perl 2 ? > > To all those questions at this stage, my answer would be 'I doubt it'. > Find out about your systems first. There are lots of tools to help > you do that. Start by checking the relevant sections of the Guide for > more information about performance and benchmarking. (Or look at the > little disc activity light. :) Thanks, I'll dig deeper.
