Re: [PATCH v2 06/18] perf test cs-etm: Replace unroll loop thread with deterministic decode test

From: James Clark

Date: Wed Jun 03 2026 - 12:43:36 EST




On 03/06/2026 3:08 pm, Leo Yan wrote:
On Tue, Jun 02, 2026 at 03:26:48PM +0100, James Clark wrote:

[...]

+# Remove open brace lines as they may not be hit depending on the compiler
+sed -i \
+ -e '/deterministic.c:8$/d' \
+ -e '/deterministic.c:15$/d' \
+ -e '/deterministic.c:23$/d' \
+ "$tmpdir/script"

Is this related to the function definition?

I can see the brace lines with change below. It might be more reliable
if adding unused function argument, which can give chance for hit
function entry.

static int function1(void)
{
...

return 0;
}

Thanks,
Leo

Originally I included the brace lines in the test and it was working even without function arguments, but Sashiko mentioned that they may not always be hit.

I think its point was that there is no hard rule about debug symbols for open braces and the behavior might change from one version of the compiler to the next, or whether there is a function prologue or inlining or not etc.

I don't think it's important to the test at all though? So to err on the side of caution it makes sense to not test for them. Unless there's a reason you think testing for open braces is important? Surely just testing for actual lines of code appearing in a certain order is enough.