2023-11-03 11:35:30

by James Clark

Subject: [PATCH] perf test: Add option to change objdump binary

All of the other Perf subcommands that use objdump have an option to
specify the binary, so add the same option to perf test.

This is useful if you have built the kernel with a different toolchain
to the system one, where the system objdump may fail to disassemble
vmlinux.

Now this can be fixed with something like this:

$ perf test --objdump llvm-objdump "object code reading"

Signed-off-by: James Clark <[email protected]>
---
tools/perf/tests/builtin-test.c | 3 +++
tools/perf/tests/code-reading.c | 2 +-
tools/perf/tests/tests.h | 1 +
3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index cb6f1dd00dc4..a8d17dd50588 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -32,6 +32,7 @@

static bool dont_fork;
const char *dso_to_test;
+const char *test_objdump_path = "objdump";

/*
* List of architecture specific tests. Not a weak symbol as the array length is
@@ -529,6 +530,8 @@ int cmd_test(int argc, const char **argv)
"Do not fork for testcase"),
OPT_STRING('w', "workload", &workload, "work", "workload to run for testing"),
OPT_STRING(0, "dso", &dso_to_test, "dso", "dso to test"),
+ OPT_STRING(0, "objdump", &test_objdump_path, "path",
+ "objdump binary to use for disassembly and annotations"),
OPT_END()
};
const char * const test_subcommands[] = { "list", NULL };
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 3af81012014e..b353358acc3a 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -185,7 +185,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf,
int ret;

fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
- ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
+ ret = snprintf(cmd, sizeof(cmd), fmt, test_objdump_path, addr, addr + len,
filename);
if (ret <= 0 || (size_t)ret >= sizeof(cmd))
return -1;
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index b394f3ac2d66..dad3d7414142 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -207,5 +207,6 @@ DECLARE_WORKLOAD(brstack);
DECLARE_WORKLOAD(datasym);

extern const char *dso_to_test;
+extern const char *test_objdump_path;

#endif /* TESTS_H */
--
2.34.1

2023-11-03 15:41:34

by Ian Rogers

Subject: Re: [PATCH] perf test: Add option to change objdump binary

On Fri, Nov 3, 2023 at 4:35 AM James Clark <[email protected]> wrote:
>
> All of the other Perf subcommands that use objdump have an option to
> specify the binary, so add the same option to perf test.
>
> This is useful if you have built the kernel with a different toolchain
> to the system one, where the system objdump may fail to disassemble
> vmlinux.
>
> Now this can be fixed with something like this:
>
> $ perf test --objdump llvm-objdump "object code reading"
>
> Signed-off-by: James Clark <[email protected]>

There is also "perf config" for things like this.

Reviewed-by: Ian Rogers <[email protected]>

Thanks,
Ian