On 3/22/24 2:58 PM, Andrii Nakryiko wrote:
On Fri, Mar 22, 2024 at 9:07 AM Yonghong Song <yonghong.song@xxxxxxxxx> wrote:
On 3/22/24 5:26 AM, Jiri Olsa wrote:
On Thu, Mar 21, 2024 at 01:01:24PM -0700, Yonghong Song wrote:
The current kprobe_multi_bench_attach/kernel test
reads sym names from /sys/kernel/tracing/available_filter_functions.
Some names do not agree with the corresponding entries in /proc/kallsyms
since the corresponding /proc/kallsyms syms have suffix '.llvm.<hash>'.
Actually, if we pass symbol names in /proc/kallsyms,
kprobe_multi_attach will be okay.
This patch added a new subtest where addresses are retrieved from
/sys/kernel/tracing/available_filter_functions_addrs, and use the
address to consule /proc/kallsyms to get the function name.
hm, I don't understand the reason for this test.. AFAICS test_kprobe_multi_bench_attach
is doing that already, just reading available_filter_functions file
both available_filter_functions_addrs and available_filter_functions have the
same functions, there's just extra addresses in available_filter_functions_addrs
The goal is to include those kernel functions filtered in patch 4.
But we cannot use the names from available_filter_functions[_addrs],
and we need to get names from /proc/kallsyms. Hence this patch.
This will test if we give names (<name>.llvm.<hash>) to kernel
for kprobe_multi_attach, things will be okay.
for patch #4 it would be good to not skip those *.llvm.* functions,
but find the full name using kallsyms. While here we can use address
Okay, I will change patch #4 to lookup /proc/kallsyms to find the
full name. If we did that, then current patch #5 is not needed.
based multi-attachment, while getting addresses from
available_filter_functions_addrs? That way we'll have a test that
benchmarks both symbol lookup paths in the kernel (where user provides
symbol names as strings) and address-based lookup (where user provides
raw addresses).
yes, we can use available_filter_functions_addrs
to have addrs available to kernel to do multi-attach.
will do. This will be yet another bench test.
+ *symsp = syms;
+ *cntp = cnt;
+
+error:
+ fclose(f);
+ hashmap__free(map);
+ if (err) {
+ for (i = 0; i < cnt; i++)
+ free(syms[i]);
+ free(syms);
+ }
+ return err;
+}
+
[...]
