On 03/01/2018 05:19 AM, Alexei Starovoitov wrote: > 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 Ping, Peter/Steven. If you have a chance, please review the series. > Patch 1 is kernel wide cleanup of pass-struct-by-value into > pass-struct-by-reference into tracepoints. > > Patch 2 minor prep work to expose number of arguments passed > into tracepoints. > > Patch 3 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 > raw_tp_fd = bpf_raw_tracepoint_open("xdp_exception"); > > // attach bpf program to given tracepoint > bpf_prog_attach(prog_fd, raw_tp_fd, BPF_RAW_TRACEPOINT); > > Ctrl-C of tracing daemon or cmdline tool will automatically > detach bpf program, unload it and unregister tracepoint probe. > More details in patch 3. > > Patch 4, 5 - user space lib and 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 > > Alexei Starovoitov (5): > treewide: remove struct-pass-by-value from tracepoints arguments > tracepoint: compute num_args at build time > bpf: introduce BPF_RAW_TRACEPOINT > libbpf: add bpf_raw_tracepoint_open helper > samples/bpf: raw tracepoint test > > arch/x86/xen/mmu_pv.c | 16 +-- > drivers/gpu/drm/i915/i915_trace.h | 13 +- > drivers/infiniband/hw/hfi1/file_ops.c | 2 +- > drivers/infiniband/hw/hfi1/trace_ctxts.h | 12 +- > drivers/s390/cio/ioasm.c | 18 +-- > drivers/s390/cio/trace.h | 50 ++++---- > fs/dax.c | 2 +- > include/linux/bpf_types.h | 1 + > include/linux/trace_events.h | 57 +++++++++ > include/linux/tracepoint-defs.h | 1 + > include/linux/tracepoint.h | 32 +++-- > include/trace/bpf_probe.h | 87 +++++++++++++ > include/trace/define_trace.h | 15 ++- > include/trace/events/f2fs.h | 2 +- > include/trace/events/fs_dax.h | 6 +- > include/trace/events/rcu.h | 4 +- > include/trace/events/xen.h | 32 ++--- > include/uapi/linux/bpf.h | 11 ++ > kernel/bpf/syscall.c | 108 ++++++++++++++++ > kernel/rcu/tree.c | 10 +- > kernel/trace/bpf_trace.c | 211 +++++++++++++++++++++++++++++++ > kernel/tracepoint.c | 27 ++-- > net/wireless/trace.h | 2 +- > samples/bpf/Makefile | 1 + > samples/bpf/bpf_load.c | 13 ++ > samples/bpf/test_overhead_raw_tp_kern.c | 17 +++ > samples/bpf/test_overhead_user.c | 12 ++ > sound/firewire/amdtp-stream-trace.h | 2 +- > tools/include/uapi/linux/bpf.h | 11 ++ > tools/lib/bpf/bpf.c | 10 ++ > tools/lib/bpf/bpf.h | 1 + > 31 files changed, 677 insertions(+), 109 deletions(-) > create mode 100644 include/trace/bpf_probe.h > create mode 100644 samples/bpf/test_overhead_raw_tp_kern.c > -- 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
