| Message ID | 20191022023226.2255076-1-yhs@fb.com |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf-next] tools/bpf: turn on llvm alu32 attribute by default | expand |
On Mon, Oct 21, 2019 at 7:32 PM Yonghong Song <yhs@fb.com> wrote: > > llvm alu32 was introduced in llvm7: > https://reviews.llvm.org/rL325987 > https://reviews.llvm.org/rL325989 > Experiments showed that in general performance > is better with alu32 enabled: > https://lwn.net/Articles/775316/ > > This patch turned on alu32 with no-flavor test_progs > which is tested most often. The flavor test at > no_alu32/test_progs can be used to test without > alu32 enabled. The Makefile check for whether > llvm supports '-mattr=+alu32 -mcpu=v3' is > removed as llvm7 should be available for recent > distributions and also latest llvm is preferred > to run bpf selftests. > > Note that jmp32 is checked by -mcpu=probe and > will be enabled if the host kernel supports it. > > Cc: Jiong Wang <jiong.wang@netronome.com> > Cc: Andrii Nakryiko <andriin@fb.com> > Signed-off-by: Yonghong Song <yhs@fb.com> > --- Sounds good to me, see minor nit below. Acked-by: Andrii Nakryiko <andriin@fb.com> > tools/testing/selftests/bpf/Makefile | 26 ++++++++------------------ > 1 file changed, 8 insertions(+), 18 deletions(-) > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index 4ff5f4aada08..5a0bca2802fe 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -32,15 +32,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test > test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ > test_cgroup_attach xdping > > -# Also test sub-register code-gen if LLVM has eBPF v3 processor support which > -# contains both ALU32 and JMP32 instructions. > -SUBREG_CODEGEN := $(shell echo "int cal(int a) { return a > 0; }" | \ > - $(CLANG) -target bpf -O2 -emit-llvm -S -x c - -o - | \ > - $(LLC) -mattr=+alu32 -mcpu=v3 2>&1 | \ > - grep 'if w') > -ifneq ($(SUBREG_CODEGEN),) > -TEST_GEN_PROGS += test_progs-alu32 > -endif > +TEST_GEN_PROGS += test_progs-no_alu32 combine this with TEST_GEN_PROGS list above, it's not conditional anymore? > > # Also test bpf-gcc, if present > ifneq ($(BPF_GCC),) > @@ -179,7 +171,7 @@ endef > # $eval()) and pass control to DEFINE_TEST_RUNNER_RULES. > # Parameters: [...]
On 10/21/19 8:01 PM, Andrii Nakryiko wrote: > On Mon, Oct 21, 2019 at 7:32 PM Yonghong Song <yhs@fb.com> wrote: >> >> llvm alu32 was introduced in llvm7: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.llvm.org_rL325987&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=NHAn2DX4M75upJno8E_Vhg5Wx0cj_CtKLDdMYJJHgVA&s=zlXKgOdNDd7V6cQk3lYECzrp8MYswrOnc-ApTPJ6Q5o&e= >> https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.llvm.org_rL325989&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=NHAn2DX4M75upJno8E_Vhg5Wx0cj_CtKLDdMYJJHgVA&s=NSHiry5gsEeL5ThRWj-kc0yfD0YpZCt-OhAsBIvwNZQ&e= >> Experiments showed that in general performance >> is better with alu32 enabled: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__lwn.net_Articles_775316_&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=NHAn2DX4M75upJno8E_Vhg5Wx0cj_CtKLDdMYJJHgVA&s=FaOOW0RJNF7B2U4JUKG2dPlKk0c1oQtnq06-eFx8mBg&e= >> >> This patch turned on alu32 with no-flavor test_progs >> which is tested most often. The flavor test at >> no_alu32/test_progs can be used to test without >> alu32 enabled. The Makefile check for whether >> llvm supports '-mattr=+alu32 -mcpu=v3' is >> removed as llvm7 should be available for recent >> distributions and also latest llvm is preferred >> to run bpf selftests. >> >> Note that jmp32 is checked by -mcpu=probe and >> will be enabled if the host kernel supports it. >> >> Cc: Jiong Wang <jiong.wang@netronome.com> >> Cc: Andrii Nakryiko <andriin@fb.com> >> Signed-off-by: Yonghong Song <yhs@fb.com> >> --- > > Sounds good to me, see minor nit below. > > Acked-by: Andrii Nakryiko <andriin@fb.com> > >> tools/testing/selftests/bpf/Makefile | 26 ++++++++------------------ >> 1 file changed, 8 insertions(+), 18 deletions(-) >> >> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile >> index 4ff5f4aada08..5a0bca2802fe 100644 >> --- a/tools/testing/selftests/bpf/Makefile >> +++ b/tools/testing/selftests/bpf/Makefile >> @@ -32,15 +32,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test >> test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ >> test_cgroup_attach xdping >> >> -# Also test sub-register code-gen if LLVM has eBPF v3 processor support which >> -# contains both ALU32 and JMP32 instructions. >> -SUBREG_CODEGEN := $(shell echo "int cal(int a) { return a > 0; }" | \ >> - $(CLANG) -target bpf -O2 -emit-llvm -S -x c - -o - | \ >> - $(LLC) -mattr=+alu32 -mcpu=v3 2>&1 | \ >> - grep 'if w') >> -ifneq ($(SUBREG_CODEGEN),) >> -TEST_GEN_PROGS += test_progs-alu32 >> -endif >> +TEST_GEN_PROGS += test_progs-no_alu32 > > combine this with TEST_GEN_PROGS list above, it's not conditional anymore? Ya, make sense. Will respin. > >> >> # Also test bpf-gcc, if present >> ifneq ($(BPF_GCC),) >> @@ -179,7 +171,7 @@ endef >> # $eval()) and pass control to DEFINE_TEST_RUNNER_RULES. >> # Parameters: > > [...] >
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 4ff5f4aada08..5a0bca2802fe 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -32,15 +32,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ test_cgroup_attach xdping -# Also test sub-register code-gen if LLVM has eBPF v3 processor support which -# contains both ALU32 and JMP32 instructions. -SUBREG_CODEGEN := $(shell echo "int cal(int a) { return a > 0; }" | \ - $(CLANG) -target bpf -O2 -emit-llvm -S -x c - -o - | \ - $(LLC) -mattr=+alu32 -mcpu=v3 2>&1 | \ - grep 'if w') -ifneq ($(SUBREG_CODEGEN),) -TEST_GEN_PROGS += test_progs-alu32 -endif +TEST_GEN_PROGS += test_progs-no_alu32 # Also test bpf-gcc, if present ifneq ($(BPF_GCC),) @@ -179,7 +171,7 @@ endef # $eval()) and pass control to DEFINE_TEST_RUNNER_RULES. # Parameters: # $1 - test runner base binary name (e.g., test_progs) -# $2 - test runner extra "flavor" (e.g., alu32, gcc-bpf, etc) +# $2 - test runner extra "flavor" (e.g., no_alu32, gcc-bpf, etc) define DEFINE_TEST_RUNNER TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2 @@ -201,7 +193,7 @@ endef # Using TRUNNER_XXX variables, provided by callers of DEFINE_TEST_RUNNER and # set up by DEFINE_TEST_RUNNER itself, create test runner build rules with: # $1 - test runner base binary name (e.g., test_progs) -# $2 - test runner extra "flavor" (e.g., alu32, gcc-bpf, etc) +# $2 - test runner extra "flavor" (e.g., no_alu32, gcc-bpf, etc) define DEFINE_TEST_RUNNER_RULES ifeq ($($(TRUNNER_OUTPUT)-dir),) @@ -272,14 +264,12 @@ TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \ $(wildcard progs/btf_dump_test_case_*.c) TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE TRUNNER_BPF_CFLAGS := -I. -I$(OUTPUT) $(BPF_CFLAGS) $(CLANG_CFLAGS) -TRUNNER_BPF_LDFLAGS := +TRUNNER_BPF_LDFLAGS := -mattr=+alu32 $(eval $(call DEFINE_TEST_RUNNER,test_progs)) -# Define test_progs-alu32 test runner. -ifneq ($(SUBREG_CODEGEN),) -TRUNNER_BPF_LDFLAGS += -mattr=+alu32 -$(eval $(call DEFINE_TEST_RUNNER,test_progs,alu32)) -endif +# Define test_progs-no_alu32 test runner. +TRUNNER_BPF_LDFLAGS := +$(eval $(call DEFINE_TEST_RUNNER,test_progs,no_alu32)) # Define test_progs BPF-GCC-flavored test runner. ifneq ($(BPF_GCC),) @@ -319,4 +309,4 @@ $(OUTPUT)/test_verifier: test_verifier.c verifier/tests.h $(BPFOBJ) | $(OUTPUT) EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) \ prog_tests/tests.h map_tests/tests.h verifier/tests.h \ - feature $(OUTPUT)/*.o $(OUTPUT)/alu32 $(OUTPUT)/bpf_gcc + feature $(OUTPUT)/*.o $(OUTPUT)/no_alu32 $(OUTPUT)/bpf_gcc
llvm alu32 was introduced in llvm7: https://reviews.llvm.org/rL325987 https://reviews.llvm.org/rL325989 Experiments showed that in general performance is better with alu32 enabled: https://lwn.net/Articles/775316/ This patch turned on alu32 with no-flavor test_progs which is tested most often. The flavor test at no_alu32/test_progs can be used to test without alu32 enabled. The Makefile check for whether llvm supports '-mattr=+alu32 -mcpu=v3' is removed as llvm7 should be available for recent distributions and also latest llvm is preferred to run bpf selftests. Note that jmp32 is checked by -mcpu=probe and will be enabled if the host kernel supports it. Cc: Jiong Wang <jiong.wang@netronome.com> Cc: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> --- tools/testing/selftests/bpf/Makefile | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-)