On Thu, 11 Feb 2010, John Jason Jordan wrote: > Date: Thu, 11 Feb 2010 20:42:30 -0800 > From: John Jason Jordan <[email protected]> > Reply-To: "General Linux/UNIX discussion and help; civil and on-topic" > <[email protected]> > To: [email protected] > Subject: Re: [PLUG] Top is lying > > On Thu, 11 Feb 2010 21:28:20 -0700 (MST) > Carlos Konstanski <[email protected]> dijo: > >> On Thu, 11 Feb 2010, John Jason Jordan wrote: >> >>> Date: Thu, 11 Feb 2010 19:19:36 -0800 >>> From: John Jason Jordan <[email protected]> >>> Reply-To: "General Linux/UNIX discussion and help; civil and >>> on-topic" <[email protected]> >>> To: PLUG <[email protected]> >>> Subject: [PLUG] Top is lying >>> >>> And so is System Monitor. >>> >>> Something is eating 100% of one of my CPUs on my Fedora 11 x86_64 >>> Thinkpad. Occasionally it drops down, at which point the other CPU >>> surges to 100%. (I think they switch back and forth, probably so one >>> of them doesn't get too tired and go on strike.) >>> >>> System Monitor shows nothing taking more than a couple percent of >>> either CPU. From the command line top also shows nothing. >>> >>> Are there other tools to sleuth this down? Commands I could use? > >> I've seen this kind of thing before. Where have I seen it? On an >> Oracle database server that was attached to a NAS via NFS. The NFS >> traffic was voluminous, and it used up some serious CPU. But it didn't >> show up as a userland process because it was all happening in the >> kernel. Top does not show you an individual process for kernel work >> unless there's some userland connector process which is doing the >> heavy lifting. >> >> So think about what you might be doing with your computer that is >> exclusively working the kernel. > > This is making sense. At least it explains why something can be eating > 100% of one of my CPUs, yet nothing shows up in top or System Monitor. > > Unfortunately, I know little of the kernel or how it works or what it > does. I do know how to use kernels to make popcorn, but that is about > it. > > Currently open apps include Vuze (Azureus), Claws Mail, and Firefox. Of > these I suspect Vuze the most. Does a bittorrent client use processes > that are exclusively working with the kernel?
The things that would cause the kernel to eat up a lot of CPU are hardware activity, since the hardware drivers are all in the kernel. If vuze is the culprit, then it would be mostly network activity, i.e. NIC card. It's more likely that vuze is MISusing kernel resources. Maybe use a lighter bittorrent client, like rtorrent. I avoid vuze because it is a misbehaving java app from hell. Carlos _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
