On Thu, 23 Mar 2017 19:31:30 -0500 Kim Phillips kim.phillips@arm.com wrote:
OK, I've trimmed out all the nitty gritty details where we were trying to compare setups, mainly because I've reached a point where I can finally run an ETM trace without locking up the machine (without having to buy an SSD for an older operating system's rootfs :).
Recipe for success - at least for this juno R2 user - is:
- Use upstream Linus' ToT as source for kernel (not OpenCSD's
tree/branches). This commit (093b995) works for me, built with ubuntu's standard gcc 6.2 cross compiler:
For the record, I've since found out that this method uses the ETB trace method, and actually produces zero valid trace data in the resulting perf.data file. It turns out that pointing create_gcov to an empty-but-valid samples perf.data file produces an empty-but-valid .gcov file, and, in turn, using that to recompile sort.c with -fauto-profile magically produces a better performing resulting executable.
So I still can't get any sort (pun intended) of trace data out of my debian-based Juno r2.
Kim