From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D37EC63697 for ; Tue, 17 Nov 2020 18:46:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91C1924181 for ; Tue, 17 Nov 2020 18:46:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ubique-spb-ru.20150623.gappssmtp.com header.i=@ubique-spb-ru.20150623.gappssmtp.com header.b="kl+WIWKT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727007AbgKQSqC (ORCPT ); Tue, 17 Nov 2020 13:46:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726575AbgKQSqA (ORCPT ); Tue, 17 Nov 2020 13:46:00 -0500 Received: from mail-ed1-x542.google.com (mail-ed1-x542.google.com [IPv6:2a00:1450:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94534C0617A6 for ; Tue, 17 Nov 2020 10:45:58 -0800 (PST) Received: by mail-ed1-x542.google.com with SMTP id e18so23586867edy.6 for ; Tue, 17 Nov 2020 10:45:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ubique-spb-ru.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8jBD6bj0JsSmbNVtR6hH8vSBzFtUGZO9+vcL7HJEL0c=; b=kl+WIWKT22jxj00XkgCeIgfXjdxE0CW1y1zt6wb6Q23RXLe+sRsesj4ZWB8NnsDuj0 BaRV+K1LxhBlOuqlgQ68BzfFAG7UWcg9V+n3hqu32qhRDUhDn/hRU+IUDjnSPLhtK8WV c5C88SxiEoxOcfnvw4E3/2i08kRvU8M9iFbZWUFhVC3lTGh9pdW7ecBWnf8w6kzeK8OC NjYqLcPHYP1vKU5qtSgly7xpxuKIFqE01MV36x63LIPfxcYgnhqzd47TRWgp9rbj+m9u c1zddgyKWT21L2Iv8o4S6X9Omb2pKpzxMpDR9GzmBxPLwV+4PJjqxutbO4YPT3esldiT Rr+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8jBD6bj0JsSmbNVtR6hH8vSBzFtUGZO9+vcL7HJEL0c=; b=H/fwUK1by9xZ0WI8hcSK397idO2ijBeBmbzvJxGD9TOuRUXkwT9AMrdll+uh2Ewvvv ZSGh7JDYHl1jWNNaxyXWfJwORzQvEvXXyhLPHkbmlDykFkDlgTiQIp4wTtN18i6ZbBTm +yJWNlAF4CmRHn0PX2mlw02R/qbzM5ntxCWQmcpx++EBrO/osz/hCWemwkI9YgTU4f3I 103mdEgkr8wxJOTOThz3XcUidve1Bjzf+pjM6GuWt4qgBonL9xNSHKSu5ZBaeSfi/59K 01z90akQ0COdTqJDfJZWMeoiuiohyx1pvHdEMmf9pxlnmiuibEfhxgHE9NkGP7r3sFHY cM0g== X-Gm-Message-State: AOAM5313Vs703WryT2P1hHAYO2ADxnP5z3BQnhUS5q82pjiMaG9palwn U5yAaMt2KdFC145pU3CcJ9Ggq46plye7f4ucPJA= X-Google-Smtp-Source: ABdhPJysw3YwOx8zohtv/zTz82yA5Kab2zBfQ73umOq910ky24fKYyWRX9umMij/4bUeFV4F+j8KOQ== X-Received: by 2002:a50:d615:: with SMTP id x21mr22438526edi.200.1605638757126; Tue, 17 Nov 2020 10:45:57 -0800 (PST) Received: from localhost ([2620:10d:c093:400::5:a9a1]) by smtp.gmail.com with ESMTPSA id p1sm12164382edx.4.2020.11.17.10.45.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Nov 2020 10:45:56 -0800 (PST) From: Dmitrii Banshchikov To: bpf@vger.kernel.org Cc: kernel-team@fb.com, rdna@fb.com, ast@kernel.org, daniel@iogearbox.net, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, andrii@kernel.org, john.fastabend@gmail.com, kpsingh@chromium.org, toke@redhat.com, netdev@vger.kernel.org, me@ubique.spb.ru Subject: [PATCH bpf-next] bpf: Add bpf_ktime_get_coarse_ns helper Date: Tue, 17 Nov 2020 18:45:49 +0000 Message-Id: <20201117184549.257280-1-me@ubique.spb.ru> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The helper uses CLOCK_MONOTONIC_COARSE source of time that is less accurate but more performant. We have a BPF CGROUP_SKB firewall that supports event logging through bpf_perf_event_output(). Each event has a timestamp and currently we use bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20 ns in time required for event logging. bpf_ktime_get_ns(): EgressLogByRemoteEndpoint 113.82ns 8.79M bpf_ktime_get_coarse_ns(): EgressLogByRemoteEndpoint 95.40ns 10.48M Signed-off-by: Dmitrii Banshchikov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 9 +++++++++ kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 13 +++++++++++++ kernel/trace/bpf_trace.c | 2 ++ tools/include/uapi/linux/bpf.h | 9 +++++++++ 6 files changed, 35 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 581b2a2e78eb..e1bcb6d7345c 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1842,6 +1842,7 @@ extern const struct bpf_func_proto bpf_copy_from_user_proto; extern const struct bpf_func_proto bpf_snprintf_btf_proto; extern const struct bpf_func_proto bpf_per_cpu_ptr_proto; extern const struct bpf_func_proto bpf_this_cpu_ptr_proto; +extern const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 162999b12790..b637b68b10a9 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3787,6 +3787,14 @@ union bpf_attr { * *ARG_PTR_TO_BTF_ID* of type *task_struct*. * Return * Pointer to the current task. + * + * u64 bpf_ktime_get_coarse_ns(void) + * Description + * Return a coarse-grained version of the time elapsed since system boot, in nanoseconds. + * Does not include time the system was suspended. + * See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**) + * Return + * Current *ktime*. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3948,6 +3956,7 @@ union bpf_attr { FN(task_storage_get), \ FN(task_storage_delete), \ FN(get_current_task_btf), \ + FN(ktime_get_coarse_ns), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 55454d2278b1..ff55cbcfbab4 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2211,6 +2211,7 @@ const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; +const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak; const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 25520f5eeaf6..78e9bb968482 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -651,6 +651,17 @@ const struct bpf_func_proto bpf_this_cpu_ptr_proto = { .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID, }; +BPF_CALL_0(bpf_ktime_get_coarse_ns) +{ + return ktime_get_coarse_ns(); +} + +const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = { + .func = bpf_ktime_get_coarse_ns, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; + const struct bpf_func_proto bpf_get_current_task_proto __weak; const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; @@ -695,6 +706,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_ringbuf_discard_proto; case BPF_FUNC_ringbuf_query: return &bpf_ringbuf_query_proto; + case BPF_FUNC_ktime_get_coarse_ns: + return &bpf_ktime_get_coarse_ns_proto; default: break; } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 02986c7b90eb..c3b2222ab573 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1354,6 +1354,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_per_cpu_ptr_proto; case BPF_FUNC_bpf_this_cpu_ptr: return &bpf_this_cpu_ptr_proto; + case BPF_FUNC_ktime_get_coarse_ns: + return &bpf_ktime_get_coarse_ns_proto; default: return NULL; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 162999b12790..b637b68b10a9 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3787,6 +3787,14 @@ union bpf_attr { * *ARG_PTR_TO_BTF_ID* of type *task_struct*. * Return * Pointer to the current task. + * + * u64 bpf_ktime_get_coarse_ns(void) + * Description + * Return a coarse-grained version of the time elapsed since system boot, in nanoseconds. + * Does not include time the system was suspended. + * See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**) + * Return + * Current *ktime*. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3948,6 +3956,7 @@ union bpf_attr { FN(task_storage_get), \ FN(task_storage_delete), \ FN(get_current_task_btf), \ + FN(ktime_get_coarse_ns), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper -- 2.24.1