From patchwork Wed Jul 3 22:30:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13722939 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B75F4194AD7; Wed, 3 Jul 2024 22:30:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720045839; cv=none; b=PMX+PqpP1Qyq/JJYXz8eD13zm9yk78sHCq7NBbtm3PuGeFrJepwED3RdQsHSdpBw+SdTQRKii8l+LgduTv1GTC9tL0M9VJnaAGPY1ccQwIQrSV26CJdH8VQmlHTm0vvF3yDcDS8lyoXJBpew7gnD7EGvYilJ7LD/eKBeKC9tJrA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720045839; c=relaxed/simple; bh=acxnBH33pEM3geRn+RlT87+ixutZtG8P8+um1GieHao=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nMyNyCid6quNkNWOLP2pH4UIDTvzFHV82tbvKg4QLaZBHPgd7b2u/+A/Eq8+fgkVyUP6mtbW5MD+HnXQnzm4W0yHwQB3BWCUW6+hHSDwK4z9hRvPAdecD78PcW8p7K7g44QMgYzLOOHXaganFWWHx6+Og0+2Pjz9ApxmmYGGyv8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j6VT55xj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="j6VT55xj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 332A3C4AF14; Wed, 3 Jul 2024 22:30:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720045839; bh=acxnBH33pEM3geRn+RlT87+ixutZtG8P8+um1GieHao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j6VT55xj8o20WsEyg0kSX/xJCELTFVVxzPJ92MaEmr2HCjGVkx8+sktB+HChuA9qs l8ZxoSo+sLRgGZAcS2bNOOR/LLOYD+cAlEnnuuugul0CdkM6Zcg9N162ScZdkMKMRe CjK9SWB1dSDPd+ppCRbt5C5gYKCjctVfyyRjZC5UZVdRL9rZJj8PqCKneqtACxqqWf 5A7cOkoIJcqVagqxPrtb+aO2kHSogwhx9ErNmzlhuQ9f1PF5xBINq7Xy1mAPodtF5c CQJz7rQq4krgOshqN+a8ZTT1z9SD4FmnGpKfc/tWMLCBo59HIjSBMZf6jWhDwFNSiY rpIiVuYorhvKw== From: Namhyung Kim To: Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, KP Singh , Song Liu , bpf@vger.kernel.org, Stephane Eranian Subject: [PATCH v3 5/8] perf bpf-filter: Support separate lost counts for each filter Date: Wed, 3 Jul 2024 15:30:32 -0700 Message-ID: <20240703223035.2024586-6-namhyung@kernel.org> X-Mailer: git-send-email 2.45.2.803.g4e1b14247a-goog In-Reply-To: <20240703223035.2024586-1-namhyung@kernel.org> References: <20240703223035.2024586-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 As the BPF filter is shared between other processes, it should have its own counter for each invocation. Add a new array map (lost_count) to save the count using the same index as the filter. It should clear the count before running the filter. Signed-off-by: Namhyung Kim --- tools/perf/util/bpf-filter.c | 37 ++++++++++++++++++-- tools/perf/util/bpf_skel/sample_filter.bpf.c | 15 ++++++-- 2 files changed, 48 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c index 37ed6c48debf..c5eb0b7eec19 100644 --- a/tools/perf/util/bpf-filter.c +++ b/tools/perf/util/bpf-filter.c @@ -260,11 +260,23 @@ int perf_bpf_filter__prepare(struct evsel *evsel, struct target *target) } if (needs_pid_hash && geteuid() != 0) { + int zero = 0; + /* The filters map is shared among other processes */ ret = update_pid_hash(evsel, entry); if (ret < 0) goto err; + fd = get_pinned_fd("dropped"); + if (fd < 0) { + ret = fd; + goto err; + } + + /* Reset the lost count */ + bpf_map_update_elem(fd, &pinned_filter_idx, &zero, BPF_ANY); + close(fd); + fd = get_pinned_fd("perf_sample_filter"); if (fd < 0) { ret = fd; @@ -347,9 +359,25 @@ int perf_bpf_filter__destroy(struct evsel *evsel) u64 perf_bpf_filter__lost_count(struct evsel *evsel) { - struct sample_filter_bpf *skel = evsel->bpf_skel; + int count = 0; + + if (list_empty(&evsel->bpf_filters)) + return 0; + + if (pinned_filter_idx >= 0) { + int fd = get_pinned_fd("dropped"); + + bpf_map_lookup_elem(fd, &pinned_filter_idx, &count); + close(fd); + } else if (evsel->bpf_skel) { + struct sample_filter_bpf *skel = evsel->bpf_skel; + int fd = bpf_map__fd(skel->maps.dropped); + int idx = 0; - return skel ? skel->bss->dropped : 0; + bpf_map_lookup_elem(fd, &idx, &count); + } + + return count; } struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(enum perf_bpf_filter_term term, @@ -402,6 +430,7 @@ int perf_bpf_filter__pin(void) /* pinned program will use pid-hash */ bpf_map__set_max_entries(skel->maps.filters, MAX_FILTERS); bpf_map__set_max_entries(skel->maps.pid_hash, MAX_PIDS); + bpf_map__set_max_entries(skel->maps.dropped, MAX_FILTERS); skel->rodata->use_pid_hash = 1; if (sample_filter_bpf__load(skel) < 0) { @@ -459,6 +488,10 @@ int perf_bpf_filter__pin(void) pr_debug("chmod for pid_hash failed\n"); ret = -errno; } + if (fchmodat(dir_fd, "dropped", 0666, 0) < 0) { + pr_debug("chmod for dropped failed\n"); + ret = -errno; + } err_close: close(dir_fd); diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c index c5273f06fa45..4c75354b84fd 100644 --- a/tools/perf/util/bpf_skel/sample_filter.bpf.c +++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c @@ -23,7 +23,14 @@ struct pid_hash { __uint(max_entries, 1); } pid_hash SEC(".maps"); -int dropped; +/* tgid to filter index */ +struct lost_count { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, int); + __uint(max_entries, 1); +} dropped SEC(".maps"); + volatile const int use_pid_hash; void *bpf_cast_to_kern_ctx(void *) __ksym; @@ -189,6 +196,7 @@ int perf_sample_filter(void *ctx) int in_group = 0; int group_result = 0; int i, k; + int *losts; kctx = bpf_cast_to_kern_ctx(ctx); @@ -252,7 +260,10 @@ int perf_sample_filter(void *ctx) return 1; drop: - __sync_fetch_and_add(&dropped, 1); + losts = bpf_map_lookup_elem(&dropped, &k); + if (losts != NULL) + __sync_fetch_and_add(losts, 1); + return 0; }