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| author | Andrii Nakryiko <andrii@kernel.org> | 2024-03-29 12:04:10 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-03-29 17:18:30 -0700 |
| commit | 623bdd58be3727318d374f0052f9dfff1e87b854 (patch) | |
| tree | 4fa897fca4d3678d7fe97924daa9a2c7d1f3ff73 | |
| parent | 59f2f841179aa6a0899cb9cf53659149a35749b7 (diff) | |
| download | perf-623bdd58be3727318d374f0052f9dfff1e87b854.tar.gz | |
selftests/bpf: make multi-uprobe tests work in RELEASE=1 mode
When BPF selftests are built in RELEASE=1 mode with -O2 optimization
level, uprobe_multi binary, called from multi-uprobe tests is optimized
to the point that all the thousands of target uprobe_multi_func_XXX
functions are eliminated, breaking tests.
So ensure they are preserved by using weak attribute.
But, actually, compiling uprobe_multi binary with -O2 takes a really
long time, and is quite useless (it's not a benchmark). So in addition
to ensuring that uprobe_multi_func_XXX functions are preserved, opt-out
of -O2 explicitly in Makefile and stick to -O0. This saves a lot of
compilation time.
With -O2, just recompiling uprobe_multi:
$ touch uprobe_multi.c
$ time make RELEASE=1 -j90
make RELEASE=1 -j90 291.66s user 2.54s system 99% cpu 4:55.52 total
With -O0:
$ touch uprobe_multi.c
$ time make RELEASE=1 -j90
make RELEASE=1 -j90 22.40s user 1.91s system 99% cpu 24.355 total
5 minutes vs (still slow, but...) 24 seconds.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240329190410.4191353-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/uprobe_multi.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 3b9eb40d63436f..b0ac3dd80acfcb 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -759,7 +759,7 @@ $(OUTPUT)/veristat: $(OUTPUT)/veristat.o $(OUTPUT)/uprobe_multi: uprobe_multi.c $(call msg,BINARY,,$@) - $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@ + $(Q)$(CC) $(CFLAGS) -O0 $(LDFLAGS) $^ $(LDLIBS) -o $@ EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR) \ prog_tests/tests.h map_tests/tests.h verifier/tests.h \ diff --git a/tools/testing/selftests/bpf/uprobe_multi.c b/tools/testing/selftests/bpf/uprobe_multi.c index a61ceab60b68a3..7ffa563ffebaa8 100644 --- a/tools/testing/selftests/bpf/uprobe_multi.c +++ b/tools/testing/selftests/bpf/uprobe_multi.c @@ -9,7 +9,7 @@ #define NAME(name, idx) PASTE(name, idx) -#define DEF(name, idx) int NAME(name, idx)(void) { return 0; } +#define DEF(name, idx) int __attribute__((weak)) NAME(name, idx)(void) { return 0; } #define CALL(name, idx) NAME(name, idx)(); #define F(body, name, idx) body(name, idx) |