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

From: Wang Nan
Date: Wed Oct 14 2015 - 08:47:24 EST

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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.

Thank you.

[1] http://lkml.kernel.org/r/1440672142-89311-1-git-send-email-xiakaixu@xxxxxxxxxx

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@xxxxxxxxxx>

----------------------------------------------------------------
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

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Next message: H. Nikolaus Schaller: "Re: [PATCH v2] ARM: fix vdsomunge not to depend on glibc specific byteswap.h"
Previous message: Wang Nan: "[PATCH 10/31] perf test: Enforce LLVM test for BPF test"
Next in thread: Wang Nan: "[PATCH 08/31] perf record: Add clang options for compiling BPF scripts"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]