I wrote a wiki page about using oprofile with Ceph. It's at: http://ceph.newdream.net/wiki/Cpu_profiling I guess we should give this a try next time we have a CPU load problem. Apparently you can get really detailed with oprofile and measure things like number of CPU pipeline stalls and cache line misses. I didn't do any of that-- just used the simple counter. Colin On Fri, Mar 4, 2011 at 12:47 PM, Colin McCabe <cmccabe@xxxxxxxxxxxxxx> wrote: > I'm testing out oprofile now. So far, it seems relatively painless, > and it is a system-wide profiler. It seems to have some kernel hooks > too... > > Colin > > > On Fri, Mar 4, 2011 at 12:40 PM, Gregory Farnum > <gregory.farnum@xxxxxxxxxxxxx> wrote: >> >> On Friday, March 4, 2011 at 12:08 PM, Colin McCabe wrote: >>> tl;dr: cpu_profiler may randomly crash your program on x86_64. >>> The problem "should" be resolved in the "future". >> >> From what I've read, it's unfortunately not out of date. However, it manifests itself as a crash so it's not the reason that we can't get debugging output, unless there's something I'm missing. :) >> And even if it turns out to be very unstable on x86-64, the value of a good cpu profiler is high enough that we can set up x86 boxes or VMs... >> -Greg >> >> >> >> > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
