On Wed, Aug 13, 2014 at 12:57 AM, Alexei Starovoitov <ast@xxxxxxxxxxxx> wrote: [...] > Tracing use case got some improvements as well. Now eBPF programs can be > attached to tracepoint, syscall, kprobe and C examples are more usable: > ex1_kern.c - demonstrate how programs can walk in-kernel data structures > ex2_kern.c - in-kernel event accounting and user space histograms > See patch #25 This is great, thanks! I've been using this new support, and successfully ported an an older tool of mine (bitesize) to eBPF. I was using the block:block_rq_issue tracepoint, and performing a custom in-kernel histogram, like in the ex2_kern.c example, for I/O size. I also did some quick overhead testing and found eBPF with JIT to be relatively fast. (I'd share numbers but it's platform specific.) The syscall tracepoints were a bit slower than hoped, for what I think is a well known issue. Are there thoughts in general for how this might be used for embedded devices, where installing clang/llvm might be prohibitive? Compile on another system and move the binaries over? thanks, Brendan -- 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
