Em Thu, May 05, 2022 at 03:30:39PM +0530, Athira Rajeev escreveu:
> Perf BPF filter test fails in environment where "clang"
> is not installed.
>
> Test failure logs:
>
> <<>>
> 42: BPF filter :
> 42.1: Basic BPF filtering : Skip
> 42.2: BPF pinning : FAILED!
> 42.3: BPF prologue generation : FAILED!
> <<>>
>
> Enabling verbose option provided debug logs which says
> clang/llvm needs to be installed. Snippet of verbose logs:
>
> <<>>
> 42.2: BPF pinning :
> --- start ---
> test child forked, pid 61423
> ERROR: unable to find clang.
> Hint: Try to install latest clang/llvm to support BPF.
> Check your $PATH
>
> <<logs_here>>
>
> Failed to compile test case: 'Basic BPF llvm compile'
> Unable to get BPF object, fix kbuild first
> test child finished with -1
> ---- end ----
> BPF filter subtest 2: FAILED!
> <<>>
>
> Here subtests, "BPF pinning" and "BPF prologue generation"
> failed and logs shows clang/llvm is needed. After installing
> clang, testcase passes.
>
> Reason on why subtest failure happens though logs has proper
> debug information:
> Main function __test__bpf calls test_llvm__fetch_bpf_obj by
> passing 4th argument as true ( 4th arguments maps to parameter
> "force" in test_llvm__fetch_bpf_obj ). But this will cause
> test_llvm__fetch_bpf_obj to skip the check for clang/llvm.
>
> Snippet of code part which checks for clang based on
> parameter "force" in test_llvm__fetch_bpf_obj:
>
> <<>>
> if (!force && (!llvm_param.user_set_param &&
> <<>>
>
> Since force is set to "false", test won't get skipped and
> fails to compile test case. The BPF code compilation needs
> clang, So pass the fourth argument as "false" and also skip
> the test if reason for return is "TEST_SKIP"
>
> After the patch:
>
> <<>>
> 42: BPF filter :
> 42.1: Basic BPF filtering : Skip
> 42.2: BPF pinning : Skip
> 42.3: BPF prologue generation : Skip
> <<>>
Wouldn't it be better to add the reason for the skip, like other tests
do?
E.g.:
23: Watchpoint :
23.1: Read Only Watchpoint : Skip
(missing hardware support)
23.2: Write Only Watchpoint : Ok
23.3: Read / Write Watchpoint : Ok
23.4: Modify Watchpoint
Something like:
After the patch:
<<>>
42: BPF filter :
42.1: Basic BPF filtering : Skip (clang not installed)
42.2: BPF pinning : Skip (clang not installed)
42.3: BPF prologue generation : Skip (clang not installed)
<<>>
> Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com>
> ---
> tools/perf/tests/bpf.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
> index 57b9591f7cbb..ae62f01239e3 100644
> --- a/tools/perf/tests/bpf.c
> +++ b/tools/perf/tests/bpf.c
> @@ -222,11 +222,11 @@ static int __test__bpf(int idx)
>
> ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
> bpf_testcase_table[idx].prog_id,
> - true, NULL);
> + false, NULL);
> if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
> pr_debug("Unable to get BPF object, %s\n",
> bpf_testcase_table[idx].msg_compile_fail);
> - if (idx == 0)
> + if ((idx == 0) || (ret == TEST_SKIP))
> return TEST_SKIP;
> else
> return TEST_FAIL;
> --
> 2.35.1
--
- Arnaldo
