Some platforms do not have CPU die support, for example s390.
Commit fdf1e29b6118 ("perf expr: Add metric literals for topology.")
fails on s390:
# ./perf test -Fv 7
...
# FAILED tests/expr.c:173 #num_dies >= #num_packages
---- end ----
Simple expression parser: FAILED!
#
Investigating this issue leads to these functions:
build_cpu_topology()
+--> has_die_topology(void)
{
struct utsname uts;
if (uname(&uts) < 0)
return false;
if (strncmp(uts.machine, "x86_64", 6))
return false;
....
}
which always returns false on s390. The caller build_cpu_topology()
checks has_die_topology() return value. On false the
the struct cpu_topology::die_cpu_list is not contructed and has zero
entries. This leads to the failing comparison: #num_dies >= #num_packages.
s390 of course has a positive number of packages.
Fix this and check if the function build_cpu_topology() did build up
a die_cpus_list. The number of entries in this list should be larger
than 0. If the number of list element is zero, the die_cpus_list has
not been created and the check in function test__expr()
TEST_ASSERT_VAL("#num_dies >= #num_packages", \
num_dies >= num_packages)
always fails.
Output after:
# ./perf test -Fv 7
7: Simple expression parser :
--- start ---
division by zero
syntax error
---- end ----
Simple expression parser: Ok
#
Cc: Ian Rogers <[email protected]>
Fixes: fdf1e29b6118 ("perf expr: Add metric literals for topology.")
Signed-off-by: Thomas Richter <[email protected]>
Acked-by: Ian Rogers <[email protected]>
---
tools/perf/tests/expr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index c895de481fe1..9356d90bf8db 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -169,7 +169,8 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u
TEST_ASSERT_VAL("#num_dies", expr__parse(&num_dies, ctx, "#num_dies") == 0);
TEST_ASSERT_VAL("#num_cores >= #num_dies", num_cores >= num_dies);
TEST_ASSERT_VAL("#num_packages", expr__parse(&num_packages, ctx, "#num_packages") == 0);
- TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);
+ if (num_dies)
+ TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);
/*
* Source count returns the number of events aggregating in a leader
--
2.31.1
Em Mon, Nov 29, 2021 at 12:23:39PM +0100, Thomas Richter escreveu:
> Some platforms do not have CPU die support, for example s390.
> Commit fdf1e29b6118 ("perf expr: Add metric literals for topology.")
> fails on s390:
> # ./perf test -Fv 7
> ...
> # FAILED tests/expr.c:173 #num_dies >= #num_packages
> ---- end ----
> Simple expression parser: FAILED!
> #
>
> Investigating this issue leads to these functions:
> build_cpu_topology()
> +--> has_die_topology(void)
> {
> struct utsname uts;
>
> if (uname(&uts) < 0)
> return false;
> if (strncmp(uts.machine, "x86_64", 6))
> return false;
> ....
> }
>
> which always returns false on s390. The caller build_cpu_topology()
> checks has_die_topology() return value. On false the
> the struct cpu_topology::die_cpu_list is not contructed and has zero
> entries. This leads to the failing comparison: #num_dies >= #num_packages.
> s390 of course has a positive number of packages.
>
> Fix this and check if the function build_cpu_topology() did build up
> a die_cpus_list. The number of entries in this list should be larger
> than 0. If the number of list element is zero, the die_cpus_list has
> not been created and the check in function test__expr()
> TEST_ASSERT_VAL("#num_dies >= #num_packages", \
> num_dies >= num_packages)
> always fails.
>
> Output after:
> # ./perf test -Fv 7
> 7: Simple expression parser :
> --- start ---
> division by zero
> syntax error
> ---- end ----
> Simple expression parser: Ok
> #
> Cc: Ian Rogers <[email protected]>
> Fixes: fdf1e29b6118 ("perf expr: Add metric literals for topology.")
>
> Signed-off-by: Thomas Richter <[email protected]>
> Acked-by: Ian Rogers <[email protected]>
> ---
> tools/perf/tests/expr.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
> index c895de481fe1..9356d90bf8db 100644
> --- a/tools/perf/tests/expr.c
> +++ b/tools/perf/tests/expr.c
> @@ -169,7 +169,8 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u
> TEST_ASSERT_VAL("#num_dies", expr__parse(&num_dies, ctx, "#num_dies") == 0);
> TEST_ASSERT_VAL("#num_cores >= #num_dies", num_cores >= num_dies);
> TEST_ASSERT_VAL("#num_packages", expr__parse(&num_packages, ctx, "#num_packages") == 0);
> - TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);
> + if (num_dies)
> + TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);
>
> /*
> * Source count returns the number of events aggregating in a leader
> --
I'll add a comment for the casual reader:
+ if (num_dies) // Some platforms do not have CPU die support, for example s390
+ TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);