On 03/28/2018 09:05 PM, Alexei Starovoitov wrote: > v7->v8: > - moved 'u32 num_args' from 'struct tracepoint' into 'struct bpf_raw_event_map' > that increases memory overhead, but can be optimized/compressed later. > Now it's zero changes in tracepoint.[ch] [...] > The first approach simply added these pointers to sched tracepoints: > https://lkml.org/lkml/2017/12/14/753 > which Peter nacked. > Few options were discussed and eventually the discussion converged on > doing bpf specific tracepoint_probe_register() probe functions. > Details here: > https://lkml.org/lkml/2017/12/20/929 > > Patch 1 is kernel wide cleanup of pass-struct-by-value into > pass-struct-by-reference into tracepoints. > > Patches 2 and 3 are minor cleanups to address allyesconfig build > > Patch 4 refactor trace_iwlwifi_dev_ucode_error from 17 to 4 args > > Patch 5 introduces COUNT_ARGS macro > > Patch 6 introduces BPF_RAW_TRACEPOINT api. > the auto-cleanup and multiple concurrent users are must have > features of tracing api. For bpf raw tracepoints it looks like: > // load bpf prog with BPF_PROG_TYPE_RAW_TRACEPOINT type > prog_fd = bpf_prog_load(...); > > // receive anon_inode fd for given bpf_raw_tracepoint > // and attach bpf program to it > raw_tp_fd = bpf_raw_tracepoint_open("xdp_exception", prog_fd); > > Ctrl-C of tracing daemon or cmdline tool will automatically > detach bpf program, unload it and unregister tracepoint probe. > More details in patch 6. > > Patch 7 - trivial support in libbpf > Patches 8, 9 - user space tests > > samples/bpf/test_overhead performance on 1 cpu: > > tracepoint base kprobe+bpf tracepoint+bpf raw_tracepoint+bpf > task_rename 1.1M 769K 947K 1.0M > urandom_read 789K 697K 750K 755K Applied to bpf-next, thanks everyone! -- 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
