(2015/03/23 13:57), Alexei Starovoitov wrote: > On 3/22/15 7:17 PM, Masami Hiramatsu wrote: >> (2015/03/23 3:03), Alexei Starovoitov wrote: >> >>> User space tools that will compile ktap/dtrace scripts into bpf might >>> use build-id for their own purpose, but that's a different discussion. >> >> Agreed. >> I'd like to discuss it since kprobe event interface may also have same >> issue. > > I'm not sure what 'issue' you're seeing. My understanding is that > build-ids are used by perf to associate binaries with their debug info > and by systemtap to make sure that probes actually match the kernel > they were compiled for. In bpf case it probably will be perf way only. Ah, I see. So perftools can check the build-id if needed, right? > Are you interested in doing something with bpf ? ;) Of course :) > I know that Jovi is working on clang-based front-end, He Kuang is doing > something fancy and I'm going to focus on 'tcp instrumentation' once > bpf+kprobes is in. I think these efforts will help us make it > concrete and will establish a path towards bpf+tracepoints > (debug tracepoints or trace markers) and eventual integration with perf. > Here is the wish-list (for kernel and userspace) inspired by Brendan: > - access to pid, uid, tid, comm, etc > - access to kernel stack trace > - access to user-level stack trace > - kernel debuginfo for walking kernel structs, and accessing kprobe > entry args as variables perf probe can provide this to bpf. > - tracing of uprobes > - tracing of user markers I'm working on the perf-cache which will also support SDT (based on Hemant Kumar's work). > - user debuginfo for user structs and args Ditto. > - easy to use language > - library of scripting features > - nice one-liner syntax > > I think there is a lot of interest in bpf+tracing and would be good to > align the efforts. Agreed :) Thanks! -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@xxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
