2015-08-17 6:31 GMT+02:00 Andi Kleen <a...@firstfloor.org>: > > Modern Intel Core CPUs (5th and 6th generation) have a Intel Processor Trace > (PT) feature > to trace branch execution with low overhead. This is useful for performance > analysis and debugging. > > simple-pt is a simple standalone driver and decoder tool to implement PT on > Linux. > > Starting with Linux 4.1 Linux has an integrated PT implementation in perf > (see https://lwn.net/Articles/648154/). > simple-pt is an alternative implementation. It has many disadvantages over > the perf PT > implementation, such as: > - needs to run as root > - no long term tracing or sampling with interrupts > - no support for interactive debugging (use gdb 7.10 on perf for that) > - no support for histograms > - somewhat experimental > - not as well supported as perf > > On the positive side simple-pt is: > - simple > - standalone. No kernel changes needed. Could be ported to older kernels or > other operating systems > - easy to modify and experiment with > - more ftrace like decoding tool > - support for kprobes based triggers > - modular “unix style” design with simple tools that do only one thing each > - BSD licensed > > Example output: > > > % sptcmd -c tcall taskset -c 0 ./tcall > cpu 0 offset 1027688, 1003 KB, writing to ptout.0 > ... > Wrote sideband to ptout.sideband > % sptdecode --sideband ptout.sideband --pt ptout.0 | less > TIME DELTA INSNs OPERATION > frequency 32 > 0 [+0] [+ 1] _dl_aux_init+436 > [+ 6] __libc_start_main+455 -> > _dl_discover_osversion > ... > [+ 13] __libc_start_main+446 -> main > [+ 9] main+22 -> f1 > [+ 4] f1+9 -> f2 > [+ 2] f1+19 -> f2 > [+ 5] main+22 -> f1 > [+ 4] f1+9 -> f2 > [+ 2] f1+19 -> f2 > [+ 5] main+22 -> f1
Nice. So I guess +x is the address offset. How hard would it be to translate to file lines? Thanks. > ... > > Available from https://github.com/andikleen/simple-pt > > -- > a...@linux.intel.com -- Speaking for myself only. > -- > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/
