(2012/08/23 18:08), Steven Rostedt wrote: > On Thu, 2012-08-23 at 12:00 +0900, Masami Hiramatsu wrote: >> (2012/08/23 11:01), Masami Hiramatsu wrote: >>> (2012/08/22 22:41), Steven Rostedt wrote: >>>> On Wed, 2012-08-22 at 17:43 +0900, Yoshihiro YUNOMAE wrote: >>>>> From: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> >>>>> >>>>> Count debugfs/tracing/per_cpu/cpu* to determine the >>>>> number of CPUs. >>>> >>>> I'm curious, do you find that sysconf doesn't return the # of CPUs the >>>> system has? >>> >>> No, sysconf returns the number of hosts CPUs, not guests. >>> >>>> I've had boxes where the per_cpu/cpu* had more cpus than the >>>> box actually holds. But this was a bug in the kernel, not the tool. This >>>> change log needs to have rational instead of just explaining what the >>>> patch does. >>> >>> Ah, I see. Hmm, then this should be enabled by a command line >>> option or an environment variable. >> >> Oops, I misunderstood. I'll add more comment for why this >> should be tried instead of sysconf. > > And now that I understand why you are doing this, why not only do this > if the TRACE_AGENT or DEBUG_TRACING_DIR is defined. That is, if we are > doing it against a bare metal system, then sysconf should suffice, but > if we are tracing against a guest, then it should use the tracing > directory to determine the buffers. > > We could add options to override this, but I would think the default > should just Do The Right Thing(tm). Yeah, so I'd like to push this is the default method, and fix the kernel bug (but I'm not sure that is a bug). Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@xxxxxxxxxxx _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
