Re: [GIT PULL 00/31] perf tools: filtering events using eBPF programs

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Wed, Oct 14, 2015 at 12:41:11PM +0000, Wang Nan wrote:
> Hi Arnaldo,
> 
>    I know you don't have enough time to review my code. I send
> this patchset to let you and other know what we are working on.
> 
>    In this new patchset, we create a new perf cmdline syntax so
> perf users are able to pass perf events created by perf to BPF
> maps, which makes bpf_perf_event_read() usable. Compare with out
> previous solution[1] which embedded 'struct perf_event_attr' to
> "maps" section, this solution is easier to use.
> 
>    If you or anyone have any different views on this solution,
> please let us know so we can stop our further development base
> on it as soon as possible.

Thanks for working on this.  I've only reviewed the first part and
will continue to review it tomorrow (or later). :)

For patch 01 - 08,

  Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> 
> Thank you.
> 
>  [1] http://lkml.kernel.org/r/1440672142-89311-1-git-send-email-xiakaixu@huawei.com
> 
> The following changes since commit 31eb4360546b4bd890f349db01295a173c09b0fb:
> 
>   perf hists browser: Add 'm' key for context menu display (2015-10-12 23:29:14 -0300)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/pi3orama/linux.git tags/perf-ebpf-for-acme-20151014
> 
> for you to fetch changes up to 6df036cb7d42a2e0ebf312e127b02425bd57bc55:
> 
>   perf tools: Enable BPF object configure syntax (2015-10-14 10:09:17 +0000)
> 
> ----------------------------------------------------------------
> EBPF support for perf
> 
>  - Rebase to newest perf/core
> 
>  - Bugfix: kprobe events not remove if bpf__probe() failure occur
>    after it creates some kprobe points successfully.
> 
>  - Bugfix: when multiple BPF functions reside in one BPF object,
>    the last BPF program would be attached to all kprobe events.
>    This bug is introduced by removal of dummy event placeholder.
> 
>  - New function: support BPF program reading counter through
>    bpf_perf_event_read() by adding new syntax and support code
>    in event selector. The new BPF object configuration mechanism
>    can be extended to support BPF data output.
> 
>    In this patchset, following BPF function can be used to measure
>    cycles a kernel function cost:
> 
>    ===== BPF program bpf_program.c =====
> 
>    struct bpf_map_def SEC("maps") pmu_map = {
>        .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
>        .key_size = sizeof(int),
>        .value_size = sizeof(u32),
>        .max_entries = __NR_CPUS__,
>    };
> 
>    SEC("func_write=sys_write")
>    int func_write(void *ctx)
>    {
>        unsigned long long val;
>        char fmt[] = "sys_write:        pmu=%llu\n";
>        val = bpf_perf_event_read(&pmu_map, bpf_get_smp_processor_id());
>        bpf_trace_printk(fmt, sizeof(fmt), val);
>        return 0;
>    }
> 
>    SEC("func_write_return=sys_write%return")
>    int func_write_return(void *ctx)
>    {
>        unsigned long long val = 0;
>        char fmt[] = "sys_write_return: pmu=%llu\n";
>        val = bpf_perf_event_read(&pmu_map, bpf_get_smp_processor_id());
>        bpf_trace_printk(fmt, sizeof(fmt), val);
>        return 0;
>    }
> 
>    With cmdline like this:
> 
>    ===== cmdline =====
>    # echo "" > /sys/kernel/debug/tracing/trace
>    # perf record -e evt=cycles/period=0x7fffffffffffffff/ \
>                  -e bpf_program.c/maps.pmu_map.event=evt/
>                  -a ls
>    # cat /sys/kernel/debug/tracing/trace | grep ls
>                 ls-3363  [003] d... 75475.056190: : sys_write:        pmu=3961415
>                 ls-3363  [003] dN.. 75475.056212: : sys_write_return: pmu=4051390
>                 ls-3363  [003] d... 75475.056216: : sys_write:        pmu=4065447
>                 ls-3363  [003] dN.. 75475.056227: : sys_write_return: pmu=4109760
>                 ls-3363  [003] d... 75475.056230: : sys_write:        pmu=4120776
>                 ls-3363  [003] dN.. 75475.056245: : sys_write_return: pmu=4178441
>                 ...
>    # perf report --stdio
>    Error:
>    The perf.data file has no samples!
> 
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> 
> ----------------------------------------------------------------
> He Kuang (5):
>       perf tools: Add prologue for BPF programs for fetching arguments
>       perf record: Support custom vmlinux path
>       bpf tools: Add helper function for updating bpf maps elements
>       perf tools: Support perf event alias name
>       perf record: Apply config to BPF objects before recording
> 
> Wang Nan (26):
>       perf tools: Make perf depend on libbpf
>       perf ebpf: Add the libbpf glue
>       perf tools: Enable passing bpf object file to --event
>       perf record, bpf: Create probe points for BPF programs
>       perf record: Load eBPF object into kernel
>       perf tools: Collect perf_evsel in BPF object files
>       perf tools: Attach eBPF program to perf event
>       perf record: Add clang options for compiling BPF scripts
>       perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
>       perf test: Enforce LLVM test for BPF test
>       perf test: Add 'perf test BPF'
>       perf probe: Reset args and nargs for probe_trace_event when failure
>       bpf tools: Load a program with different instances using preprocessor
>       perf tools: Add BPF_PROLOGUE config options for further patches
>       perf tools: Compile dwarf-regs.c if CONFIG_BPF_PROLOGUE is on
>       perf tools: Generate prologue for BPF programs
>       perf tools: Use same BPF program if arguments are identical
>       perf tools: Allow BPF program attach to uprobe events
>       perf test: Enforce LLVM test, add kbuild test
>       perf test: Test BPF prologue
>       bpf tools: Collect map definition in bpf_object
>       bpf tools: Extract and collect map names from BPF object file
>       perf tools: Pass available CPU number to clang compiler
>       perf tools: Add API to config maps in bpf object
>       perf tools: Add API to apply config to BPF map
>       perf tools: Enable BPF object configure syntax
> 
>  tools/build/Makefile.feature                |   6 +-
>  tools/lib/bpf/bpf.c                         |  14 +
>  tools/lib/bpf/bpf.h                         |   2 +
>  tools/lib/bpf/libbpf.c                      | 392 +++++++++---
>  tools/lib/bpf/libbpf.h                      |  46 ++
>  tools/perf/MANIFEST                         |   3 +
>  tools/perf/Makefile.perf                    |  21 +-
>  tools/perf/arch/x86/util/Build              |   1 +
>  tools/perf/builtin-record.c                 |  21 +
>  tools/perf/config/Makefile                  |  31 +-
>  tools/perf/perf.c                           |   2 +
>  tools/perf/tests/Build                      |  24 +-
>  tools/perf/tests/bpf-script-example.c       |  48 ++
>  tools/perf/tests/bpf-script-test-kbuild.c   |  21 +
>  tools/perf/tests/bpf-script-test-prologue.c |  35 ++
>  tools/perf/tests/bpf.c                      | 227 +++++++
>  tools/perf/tests/builtin-test.c             |  10 +
>  tools/perf/tests/llvm.c                     | 210 ++++++-
>  tools/perf/tests/llvm.h                     |  29 +
>  tools/perf/tests/make                       |   4 +-
>  tools/perf/tests/tests.h                    |   5 +
>  tools/perf/util/Build                       |   2 +
>  tools/perf/util/bpf-loader.c                | 933 ++++++++++++++++++++++++++++
>  tools/perf/util/bpf-loader.h                | 148 +++++
>  tools/perf/util/bpf-prologue.c              | 443 +++++++++++++
>  tools/perf/util/bpf-prologue.h              |  34 +
>  tools/perf/util/evlist.c                    |  16 +
>  tools/perf/util/evlist.h                    |   4 +
>  tools/perf/util/evsel.c                     |  17 +
>  tools/perf/util/evsel.h                     |   2 +
>  tools/perf/util/llvm-utils.c                |  24 +-
>  tools/perf/util/parse-events.c              | 221 ++++++-
>  tools/perf/util/parse-events.h              |  15 +
>  tools/perf/util/parse-events.l              |   6 +
>  tools/perf/util/parse-events.y              |  55 +-
>  tools/perf/util/probe-finder.c              |   4 +
>  36 files changed, 2968 insertions(+), 108 deletions(-)
>  create mode 100644 tools/perf/tests/bpf-script-example.c
>  create mode 100644 tools/perf/tests/bpf-script-test-kbuild.c
>  create mode 100644 tools/perf/tests/bpf-script-test-prologue.c
>  create mode 100644 tools/perf/tests/bpf.c
>  create mode 100644 tools/perf/tests/llvm.h
>  create mode 100644 tools/perf/util/bpf-loader.c
>  create mode 100644 tools/perf/util/bpf-loader.h
>  create mode 100644 tools/perf/util/bpf-prologue.c
>  create mode 100644 tools/perf/util/bpf-prologue.h
> 
> -- 
> 1.8.3.4
>