From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D5FF324B3A for ; Tue, 23 Sep 2025 13:10:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758633011; cv=none; b=PTmnxvqJ6XGav/AX1PMoIF9RPYjFpcFe3g/6fLzfKMsjb6NHuIo/LmfQol6cYQPzU+zrAOySLct9DHHDq6wJMD17NSYQKbjzCJvQeUYTcDNYHYGisPHRteecGIIPQXDKqESzgnzYq0BMuu0Ct9uLATA10Xzq3G0a3GEx73Ch81M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758633011; c=relaxed/simple; bh=6faPrKhC4NMG6PQdq9dP76Bloco49H2pxLGyjKfV+Lk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MOoqDS+7UonCxE7al/YA/nuNKB/Akj1Ar63adoFFOeqdQoWLPsicdSxxR6wAxXfNVNZnj0sSstDYLDJO5YwSyNitl8E00KROjMNkwnBVco5j1tIFFOKHYNrHZlW8DkOUFuPcWKgepT5EAHt+Xf1nfOSP9Rxp17c/IDn9nmYcQkM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=wUkB1xKV; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="wUkB1xKV" Message-ID: <11ee08fb-a7a9-4b9d-a842-cced1c58ca62@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1758632996; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tapR2V/1AAphhU0r21EryB+FStxCZR4Nu+likupyaP8=; b=wUkB1xKVaQPhh8k6SK23+ZCoHfUvbrmAJnUV4N/GY5HQcATpGfiYyrfnNweAoxPciwxOAv R0vcpXgrv84arFOqfCkOCO0ljGnSGTYvgmKsVTYuIquYXdd6xtDCM7Pja0fJuM1m2gThbp FZGM5olXk+0tGPLh9khPXLU34J7yMe0= Date: Tue, 23 Sep 2025 21:09:43 +0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v4 2/2] selftests/bpf: Add stacktrace map lookup_and_delete_elem test case To: Andrii Nakryiko Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250922140317.1468691-1-chen.dylane@linux.dev> <20250922140317.1468691-2-chen.dylane@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Tao Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2025/9/23 04:58, Andrii Nakryiko 写道: > On Mon, Sep 22, 2025 at 7:03 AM Tao Chen wrote: >> >> Add tests for stacktrace map lookup and delete: >> 1. use bpf_map_lookup_and_delete_elem to lookup and delete the target >> stack_id, >> 2. lookup the deleted stack_id again to double check. >> >> Signed-off-by: Tao Chen >> --- >> .../selftests/bpf/prog_tests/stacktrace_map.c | 21 ++++++++++++++++++- >> .../selftests/bpf/progs/test_stacktrace_map.c | 8 +++++++ >> 2 files changed, 28 insertions(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c >> index 84a7e405e91..d50659fc25e 100644 >> --- a/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c >> +++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c >> @@ -3,7 +3,7 @@ >> >> void test_stacktrace_map(void) >> { >> - int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; >> + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd, stack_key_map_fd; >> const char *prog_name = "oncpu"; >> int err, prog_fd, stack_trace_len; >> const char *file = "./test_stacktrace_map.bpf.o"; >> @@ -11,6 +11,8 @@ void test_stacktrace_map(void) >> struct bpf_program *prog; >> struct bpf_object *obj; >> struct bpf_link *link; >> + __u32 stack_id; >> + char val_buf[PERF_MAX_STACK_DEPTH * sizeof(struct bpf_stack_build_id)]; >> >> err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); >> if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) >> @@ -41,6 +43,10 @@ void test_stacktrace_map(void) >> if (CHECK_FAIL(stack_amap_fd < 0)) >> goto disable_pmu; >> >> + stack_key_map_fd = bpf_find_map(__func__, obj, "stack_key_map"); >> + if (CHECK_FAIL(stack_key_map_fd < 0)) > > please don't use CHECK*() macros, they are superseded by more targeted > ASSERT_xxx() ones > got it, thanks. > pw-bot: cr > > >> + goto disable_pmu; >> + >> /* give some time for bpf program run */ >> sleep(1); >> >> @@ -68,6 +74,19 @@ void test_stacktrace_map(void) >> "err %d errno %d\n", err, errno)) >> goto disable_pmu; >> >> + err = bpf_map_lookup_elem(stack_key_map_fd, &key, &stack_id); >> + if (CHECK(err, "stack_key_map lookup", "err %d errno %d\n", err, errno)) >> + goto disable_pmu; >> + >> + err = bpf_map_lookup_and_delete_elem(stackmap_fd, &stack_id, &val_buf); >> + if (CHECK(err, "stackmap lookup and delete", >> + "err %d errno %d\n", err, errno)) >> + goto disable_pmu; >> + >> + err = bpf_map_lookup_elem(stackmap_fd, &stack_id, &val_buf); >> + CHECK((!err || errno != ENOENT), "stackmap lookup deleted stack_id", >> + "err %d errno %d\n", err, errno); > > bpf_map_lookup_elem() returns error code directly, no need to use > errno, just check that err == -ENOENT > ok. >> + >> disable_pmu: >> bpf_link__destroy(link); >> close_prog: >> diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c >> index 47568007b66..3bede76c151 100644 >> --- a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c >> +++ b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c >> @@ -38,6 +38,13 @@ struct { >> __type(value, stack_trace_t); >> } stack_amap SEC(".maps"); >> >> +struct { >> + __uint(type, BPF_MAP_TYPE_ARRAY); >> + __uint(max_entries, 1); >> + __type(key, __u32); >> + __type(value, __u32); >> +} stack_key_map SEC(".maps"); >> + >> /* taken from /sys/kernel/tracing/events/sched/sched_switch/format */ >> struct sched_switch_args { >> unsigned long long pad; >> @@ -64,6 +71,7 @@ int oncpu(struct sched_switch_args *ctx) >> /* The size of stackmap and stackid_hmap should be the same */ >> key = bpf_get_stackid(ctx, &stackmap, 0); >> if ((int)key >= 0) { >> + bpf_map_update_elem(&stack_key_map, &val, &key, 0); > > ugh... you'd just use a global variable if this test was used through > skeleton... maybe convert the test to skeleton and get rid of all > those unnecessary bpf_find_map() calls as well? > Yes, the test case seems too old, i will refactor it with skeleton. >> bpf_map_update_elem(&stackid_hmap, &key, &val, 0); >> stack_p = bpf_map_lookup_elem(&stack_amap, &key); >> if (stack_p) >> -- >> 2.48.1 >> -- Best Regards Tao Chen