On 03/24/2018 03:30 AM, Alexei Starovoitov wrote: > From: Alexei Starovoitov <a...@kernel.org> > > v4->v5: > - adopted Daniel's fancy REPEAT macro in bpf_trace.c in patch 7 > > v3->v4: > - adopted Linus's CAST_TO_U64 macro to cast any integer, pointer, or small > struct to u64. That nicely reduced the size of patch 1 > > v2->v3: > - with Linus's suggestion introduced generic COUNT_ARGS and CONCATENATE macros > (or rather moved them from apparmor) > that cleaned up patches 6 and 7 > - added patch 4 to refactor trace_iwlwifi_dev_ucode_error() from 17 args to 4 > Now any tracepoint with >12 args will have build error > > v1->v2: > - simplified api by combing bpf_raw_tp_open(name) + bpf_attach(prog_fd) into > bpf_raw_tp_open(name, prog_fd) as suggested by Daniel. > That simplifies bpf_detach as well which is now simple close() of fd. > - fixed memory leak in error path which was spotted by Daniel. > - fixed bpf_get_stackid(), bpf_perf_event_output() called from raw tracepoints > - added more tests > - fixed allyesconfig build caught by buildbot > > v1: > This patch set is a different way to address the pressing need to access > task_struct pointers in sched tracepoints from bpf programs. > > 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 minor prep work to expose number of arguments passed > into tracepoints. > > Patch 7 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 7. > > Patch 8 - trivial support in libbpf > Patches 9, 10 - 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 Alexei!
