On 05/10/2023 08:19, Jiri Olsa wrote: > On Wed, Oct 04, 2023 at 10:21:12AM -0700, Andrii Nakryiko wrote: >> On Wed, Oct 4, 2023 at 1:27 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote: >>> >>> On Tue, Oct 03, 2023 at 05:17:49PM -0700, Andrii Nakryiko wrote: >>>> Add support for building selftests with -O2 level of optimization, which >>>> allows more compiler warnings detection (like lots of potentially >>>> uninitialized usage), but also is useful to have a faster-running test >>>> for some CPU-intensive tests. >>>> >>>> One can build optimized versions of libbpf and selftests by running: >>>> >>>> $ make RELEASE=1 >>>> >>>> There is a measurable speed up of about 10 seconds for me locally, >>>> though it's mostly capped by non-parallelized serial tests. User CPU >>>> time goes down by total 40 seconds, from 1m10s to 0m28s. >>>> >>>> Unoptimized build (-O0) >>>> ======================= >>>> Summary: 430/3544 PASSED, 25 SKIPPED, 4 FAILED >>>> >>>> real 1m59.937s >>>> user 1m10.877s >>>> sys 3m14.880s >>>> >>>> Optimized build (-O2) >>>> ===================== >>>> Summary: 425/3543 PASSED, 25 SKIPPED, 9 FAILED >>>> >>>> real 1m50.540s >>>> user 0m28.406s >>>> sys 3m13.198s >>> >>> hi, >>> I get following error when running selftest compiled with RELEASE=1 >>> >>> # ./test_progs -t attach_probe/manual-legacy >>> test_attach_probe:PASS:skel_open 0 nsec >>> test_attach_probe:PASS:skel_load 0 nsec >>> test_attach_probe:PASS:check_bss 0 nsec >>> test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec >>> test_attach_probe_manual:PASS:skel_kprobe_manual_open_and_load 0 nsec >>> test_attach_probe_manual:PASS:uprobe_offset 0 nsec >>> test_attach_probe_manual:PASS:attach_kprobe 0 nsec >>> test_attach_probe_manual:PASS:attach_kretprobe 0 nsec >>> test_attach_probe_manual:PASS:attach_uprobe 0 nsec >>> test_attach_probe_manual:PASS:attach_uretprobe 0 nsec >>> libbpf: failed to add legacy uprobe event for /proc/self/exe:0x19020: -17 >>> libbpf: prog 'handle_uprobe_byname': failed to create uprobe '/proc/self/exe:0x19020' perf event: File exists >>> test_attach_probe_manual:FAIL:attach_uprobe_byname unexpected error: -17 >>> #8/2 attach_probe/manual-legacy:FAIL >>> #8 attach_probe:FAIL >>> >>> >>> it looks like -O2 can merge some of the trigger functions: >>> >>> [root@qemu bpf]# nm test_progs | grep trigger_func >>> 0000000000558f30 t autoattach_trigger_func.constprop.0 >>> 000000000041d240 t trigger_func >>> 0000000000419020 t trigger_func >>> 0000000000420e70 t trigger_func >>> 0000000000507aa0 t trigger_func >>> 0000000000419020 t trigger_func2 >>> 0000000000419020 t trigger_func3 >>> 0000000000419030 t trigger_func4 >>> [root@qemu bpf]# nm test_progs | grep 0000000000419020 >>> 0000000000419020 t trigger_func >>> 0000000000419020 t trigger_func2 >>> 0000000000419020 t trigger_func3 >>> >>> I got more tests fails, but I suspect it's all for similar >>> reason like above >>> >> This one is an interesting failure that definitely seems worth fixing; as above trigger_func2 and trigger_func3 were merged it looks like, and the legacy perf_event_kprobe_open_legacy()-based attach failed due to add_uprobe_event_legacy() failing. The latter seems to be down to the way that gen_uprobe_legacy_event_name() constructs legacy event names via pid, binary_path and offset. In this case it will construct the same name for trigger_func2 and trigger_func3, hence the -EEXIST. It _seems_ like a fix here would be to add an optional func_name to gen_uprobe_legacy_event_name(). At least it appears that the non-legacy attach handles this case, which is great. Regardless, we can follow up with some of this stuff later. >> yes, I didn't say that -O2 version passes all tests :) at least there >> are complicated USDT cases under -O2 which libbpf can't support (if I >> remember correctly, it was offset relative to global symbol case). But >> it's the first step. And once we have ability to build with RELEASE=1, >> we can add it as a separate test in CI and catch more of these >> uninitialized usage errors. Initially we can denylist tests that are >> broken due to -O2 and work to fix them. > Sounds good to me; it's a great change as we're more likely to hit more problems that users run into. For the series: Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > I see ;-) sounds good > > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > jirka > >> >>> jirka >>> >>> >>>> >>>> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> >>>> --- >>>> tools/testing/selftests/bpf/Makefile | 14 ++++++++------ >>>> 1 file changed, 8 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile >>>> index a25e262dbc69..55d1b1848e6c 100644 >>>> --- a/tools/testing/selftests/bpf/Makefile >>>> +++ b/tools/testing/selftests/bpf/Makefile >>>> @@ -27,7 +27,9 @@ endif >>>> BPF_GCC ?= $(shell command -v bpf-gcc;) >>>> SAN_CFLAGS ?= >>>> SAN_LDFLAGS ?= $(SAN_CFLAGS) >>>> -CFLAGS += -g -O0 -rdynamic \ >>>> +RELEASE ?= >>>> +OPT_FLAGS ?= $(if $(RELEASE),-O2,-O0) >>>> +CFLAGS += -g $(OPT_FLAGS) -rdynamic \ >>>> -Wall -Werror \ >>>> $(GENFLAGS) $(SAN_CFLAGS) \ >>>> -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \ >>>> @@ -241,7 +243,7 @@ $(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) >>>> BPFTOOL_OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \ >>>> BPFOBJ_OUTPUT=$(BUILD_DIR)/libbpf \ >>>> BPFOBJ=$(BPFOBJ) BPF_INCLUDE=$(INCLUDE_DIR) \ >>>> - EXTRA_CFLAGS='-g -O0 $(SAN_CFLAGS)' \ >>>> + EXTRA_CFLAGS='-g $(OPT_FLAGS) $(SAN_CFLAGS)' \ >>>> EXTRA_LDFLAGS='$(SAN_LDFLAGS)' && \ >>>> cp $(RUNQSLOWER_OUTPUT)runqslower $@ >>>> >>>> @@ -279,7 +281,7 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ >>>> $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/bpftool >>>> $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ >>>> ARCH= CROSS_COMPILE= CC="$(HOSTCC)" LD="$(HOSTLD)" \ >>>> - EXTRA_CFLAGS='-g -O0' \ >>>> + EXTRA_CFLAGS='-g $(OPT_FLAGS)' \ >>>> OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \ >>>> LIBBPF_OUTPUT=$(HOST_BUILD_DIR)/libbpf/ \ >>>> LIBBPF_DESTDIR=$(HOST_SCRATCH_DIR)/ \ >>>> @@ -290,7 +292,7 @@ $(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ >>>> $(BPFOBJ) | $(BUILD_DIR)/bpftool >>>> $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ >>>> ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) \ >>>> - EXTRA_CFLAGS='-g -O0' \ >>>> + EXTRA_CFLAGS='-g $(OPT_FLAGS)' \ >>>> OUTPUT=$(BUILD_DIR)/bpftool/ \ >>>> LIBBPF_OUTPUT=$(BUILD_DIR)/libbpf/ \ >>>> LIBBPF_DESTDIR=$(SCRATCH_DIR)/ \ >>>> @@ -313,7 +315,7 @@ $(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \ >>>> $(APIDIR)/linux/bpf.h \ >>>> | $(BUILD_DIR)/libbpf >>>> $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \ >>>> - EXTRA_CFLAGS='-g -O0 $(SAN_CFLAGS)' \ >>>> + EXTRA_CFLAGS='-g $(OPT_FLAGS) $(SAN_CFLAGS)' \ >>>> EXTRA_LDFLAGS='$(SAN_LDFLAGS)' \ >>>> DESTDIR=$(SCRATCH_DIR) prefix= all install_headers >>>> >>>> @@ -322,7 +324,7 @@ $(HOST_BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \ >>>> $(APIDIR)/linux/bpf.h \ >>>> | $(HOST_BUILD_DIR)/libbpf >>>> $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) \ >>>> - EXTRA_CFLAGS='-g -O0' ARCH= CROSS_COMPILE= \ >>>> + EXTRA_CFLAGS='-g $(OPT_FLAGS)' ARCH= CROSS_COMPILE= \ >>>> OUTPUT=$(HOST_BUILD_DIR)/libbpf/ \ >>>> CC="$(HOSTCC)" LD="$(HOSTLD)" \ >>>> DESTDIR=$(HOST_SCRATCH_DIR)/ prefix= all install_headers >>>> -- >>>> 2.34.1 >>>> >>>> >
