On Wed, Jun 26, 2013 at 02:14:30PM +0200, Ingo Molnar wrote: > > * Nathan Zimmer <nzim...@sgi.com> wrote: > > > perf seems to struggle with 512 cpus, but I did get some data. > > Btw., mind outlining in what way it struggles? > > Thanks, > > Ingo
System interactivity take a nose dive, including the ability to halt perf. The commands do get through but they take a while. Other processes tend to make signifigantly reduced progress. Also it tends to slow down all running processes. My guess it is the NMIs overwhelming the system but I have not found a good way to profile perf gone wild so it is only a guess. The issue mitigate somewhat by restrictring the number of cpus perf is recording or by not using the -g option, but sometimes I do need data on the whole system. Nate -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
