On 8/27/15 3:42 AM, Kaixu Xia wrote:
An example is pasted at the bottom of this cover letter. In that example, we can get the cpu_cycles and exception taken in sys_write.$ cat /sys/kernel/debug/tracing/trace_pipe $ ./perf record --event perf-bpf.o ls ... cat-1653 [003] d..1 88174.613854: : ente: CPU-3 cyc:48746333 exc:84 cat-1653 [003] d..2 88174.613861: : exit: CPU-3 cyc:48756041 exc:84
nice. probably more complex example that computes the delta of the pmu counters on the kernel side would be even more interesting. Do you think you can extend 'perf stat' with a flag that does stats collection for a given kernel or user function instead of the whole process ? Then we can use perf record/report to figure out hot functions and follow with 'perf stat -f my_hot_func my_process' to drill into particular function stats. -- 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/
