Re: pmcstat -z32 -G truncates callgraph to 8
On 31 October 2014 01:26, Brendan Gregg brendan.d.gr...@gmail.com wrote: Yes. When I'm using profiling data, I like full stacks for making flame graphs. For the FreeBSD kernel, 32 frames should usually be enough (I have a flame graph that reaches 24 frames for the kernel, but no more). For user-level, I'd probably need ~100. So making the compiled-in default to 32 would hopefully be sufficient for most kernel profiling, and one would need to bump that up for deep user-level stacks. I guess this would also need PMC_CALLCHAIN_DEPTH_MAX = 128 to work. I have a review up to bump the default to 32 and the maximum to 128: https://reviews.freebsd.org/D1203 ___ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to freebsd-performance-unsubscr...@freebsd.org
Re: pmcstat -z32 -G truncates callgraph to 8
G'Day Ed, On Wed, Oct 29, 2014 at 12:40 PM, Ed Maste ema...@freebsd.org wrote: On 28 October 2014 13:38, Brendan Gregg brendan.d.gr...@gmail.com wrote: Ah, thanks, I'm on 10.0-STABLE and I have: kern.hwpmc.callchaindepth: 8 Glad it's something simple! Those are the best kinds of problems to have, although we ought to make sure this point is covered in the FreeBSD profiling documentation that we have or create. Yes; at least we have this thread now, which should be searchable. Also, do you think that we should bump the compiled-in default up to 32? Yes. When I'm using profiling data, I like full stacks for making flame graphs. For the FreeBSD kernel, 32 frames should usually be enough (I have a flame graph that reaches 24 frames for the kernel, but no more). For user-level, I'd probably need ~100. So making the compiled-in default to 32 would hopefully be sufficient for most kernel profiling, and one would need to bump that up for deep user-level stacks. I guess this would also need PMC_CALLCHAIN_DEPTH_MAX = 128 to work. Brendan ___ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to freebsd-performance-unsubscr...@freebsd.org
Re: pmcstat -z32 -G truncates callgraph to 8
On 28 October 2014 13:38, Brendan Gregg brendan.d.gr...@gmail.com wrote: Ah, thanks, I'm on 10.0-STABLE and I have: kern.hwpmc.callchaindepth: 8 Glad it's something simple! Those are the best kinds of problems to have, although we ought to make sure this point is covered in the FreeBSD profiling documentation that we have or create. Also, do you think that we should bump the compiled-in default up to 32? ___ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to freebsd-performance-unsubscr...@freebsd.org
