From patchwork Tue Jul 30 18:41:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zijian Zhang X-Patchwork-Id: 13747776 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-qv1-f54.google.com (mail-qv1-f54.google.com [209.85.219.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 68FA81AA3F1 for ; Tue, 30 Jul 2024 18:41:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722364919; cv=none; b=VNxhZ4I+YJ5ff5O6b9IEidFOydM0mIIq0kQlvzjC/iQ5xZwccLTdGWe3fati1TE7vw/Gj3uoLLZdzdSijFIzpaiGdiNVejk+ZbkhEHbp4TfVrvdBHwB62P+oVb/v9CiiGxXEzHdOpdyBKCwN+jJ3/FZi5nHe383PpfPtODftjYc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722364919; c=relaxed/simple; bh=eVwjcXh08v/BloRCWi+Au5NPRXGgBtqnMqSrhA86WPE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=at0AW1CxDUcYhMRFvZwialk2aT2G4LOkGxL7tC+ijv0OsLf1l+SZq6qxzUe1+59d5unQHOtnEkQYqJ2pMqvs2VvkwE4O3og396PHHn36yyRvuFlg+jk7P7EVhyVrmGHG7YocWBVpbVrWkDLUMcWdeTPsLCmTAYuyLYK9u5osbYU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=hXeM36iD; arc=none smtp.client-ip=209.85.219.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="hXeM36iD" Received: by mail-qv1-f54.google.com with SMTP id 6a1803df08f44-6b7a4668f07so25982366d6.1 for ; Tue, 30 Jul 2024 11:41:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1722364916; x=1722969716; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=NFMubqDRuXqmoPI75vXrJ4qmre3+FeuST3BNycNrURg=; b=hXeM36iD6OHIsil52wi4n4FE7dcH7zsMPiZ52xBq1wkrJ9bR9xcA2JXbKrb1Qs/Bhe Sg+W9KcYrRGs/cSbbm7sM2Yeeuj8rKg7bs8FKl2PSthrEEPsHKRsy0whzDjlpb+bQk7H qTWZmXRUQl5YiYhQPWr6R22sXQTgHrfRmrxC52AejtOJbCQGECA1JoF0snwkdGvxc6MY j9/wi9ukXD9NnBUwKsZDYqvEf+GCfGWBKGo0bdjFBUIHoNkYXsLs6kB1m7Reo22TGmeg kL/YotP9qHGB8OBwEXZnQLuO77mydYYqnBClkoV0NF4PqmVOCTSFh4VQe4fEANnAzgTa IQMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722364916; x=1722969716; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NFMubqDRuXqmoPI75vXrJ4qmre3+FeuST3BNycNrURg=; b=tP54dDcXnKmfaXShRXbNnu9voxFolEQOLpIHARxekezLhTPvWCRmuiw5FfDh1lYNWB p2c4NzWq38pxUYvYXXOvH8UVIGvauWUhi2UddusNeOET9syjLzrwmMBcUtm9vPZnk3eu PPVdr+mNsNm02f8qyAvWZ/KQc85+zrkq3nFf10Zbf4Sf8QFbockKaFvXJYT32lQwW0bB lwusajQkqtj3R3ocKmJ2j5Il5jY9XqNuk+5qjBoEcyEAznc0DN65RffU4alNOVq1IhcC 3c9zRCjR+pcQYOB5kBFwNF1s7VJxQTHzAIP4R6upIhJt8nu7qn6Si4BuZgi42/k1DWfd be4Q== X-Gm-Message-State: AOJu0YwlJNd5BHSfojrBbi4Z2N5IoinwV51bw5SKWlxZWFNYwoaVseaC Jj8OU3S82nidnawSbO0+dxzf1GPbtOb+inbH0RUV1qj7nxfvXr2z73vo8HfcP8dbnvfUHtJ4Wzn 3 X-Google-Smtp-Source: AGHT+IGqMyyvOhsKtdiERws+A5taOq1D0dtDaWZ6YlDnhO029w/RAeUiX/89Qw+mJRbm+r6IQGTcBg== X-Received: by 2002:a05:6214:dc6:b0:6b5:434:cc86 with SMTP id 6a1803df08f44-6bb559f9338mr224388956d6.10.1722364915909; Tue, 30 Jul 2024 11:41:55 -0700 (PDT) Received: from n191-036-066.byted.org ([139.177.233.173]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6bb3fb07bf7sm66132716d6.137.2024.07.30.11.41.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jul 2024 11:41:54 -0700 (PDT) From: zijianzhang@bytedance.com To: netdev@vger.kernel.org Cc: linux-api@vger.kernel.org, willemdebruijn.kernel@gmail.com, almasrymina@google.com, edumazet@google.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, axboe@kernel.dk, shuah@kernel.org, linux-kselftest@vger.kernel.org, cong.wang@bytedance.com, xiaochun.lu@bytedance.com, Zijian Zhang Subject: [PATCH net-next v8 3/3] selftests: add MSG_ZEROCOPY msg_control notification test Date: Tue, 30 Jul 2024 18:41:20 +0000 Message-Id: <20240730184120.4089835-4-zijianzhang@bytedance.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240730184120.4089835-1-zijianzhang@bytedance.com> References: <20240730184120.4089835-1-zijianzhang@bytedance.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Zijian Zhang We update selftests/net/msg_zerocopy.c to accommodate the new mechanism, cfg_notification_limit has the same semantics for both methods. Test results are as follows, we update skb_orphan_frags_rx to the same as skb_orphan_frags to support zerocopy in the localhost test. cfg_notification_limit = 1, both method get notifications after 1 calling of sendmsg. In this case, the new method has around 17% cpu savings in TCP and 23% cpu savings in UDP. +---------------------+---------+---------+---------+---------+ | Test Type / Protocol| TCP v4 | TCP v6 | UDP v4 | UDP v6 | +---------------------+---------+---------+---------+---------+ | ZCopy (MB) | 7523 | 7706 | 7489 | 7304 | +---------------------+---------+---------+---------+---------+ | New ZCopy (MB) | 8834 | 8993 | 9053 | 9228 | +---------------------+---------+---------+---------+---------+ | New ZCopy / ZCopy | 117.42% | 116.70% | 120.88% | 126.34% | +---------------------+---------+---------+---------+---------+ cfg_notification_limit = 32, both get notifications after 32 calling of sendmsg, which means more chances to coalesce notifications, and less overhead of poll + recvmsg for the original method. In this case, the new method has around 7% cpu savings in TCP and slightly better cpu usage in UDP. In the env of selftest, notifications of TCP are more likely to be out of order than UDP, it's easier to coalesce more notifications in UDP. The original method can get one notification with range of 32 in a recvmsg most of the time. In TCP, most notifications' range is around 2, so the original method needs around 16 recvmsgs to get notified in one round. That's the reason for the "New ZCopy / ZCopy" diff in TCP and UDP here. +---------------------+---------+---------+---------+---------+ | Test Type / Protocol| TCP v4 | TCP v6 | UDP v4 | UDP v6 | +---------------------+---------+---------+---------+---------+ | ZCopy (MB) | 8842 | 8735 | 10072 | 9380 | +---------------------+---------+---------+---------+---------+ | New ZCopy (MB) | 9366 | 9477 | 10108 | 9385 | +---------------------+---------+---------+---------+---------+ | New ZCopy / ZCopy | 106.00% | 108.28% | 100.31% | 100.01% | +---------------------+---------+---------+---------+---------+ In conclusion, when notification interval is small or notifications are hard to be coalesced, the new mechanism is highly recommended. Otherwise, the performance gain from the new mechanism is very limited. Signed-off-by: Zijian Zhang Signed-off-by: Xiaochun Lu --- tools/testing/selftests/net/msg_zerocopy.c | 101 ++++++++++++++++++-- tools/testing/selftests/net/msg_zerocopy.sh | 1 + 2 files changed, 95 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/net/msg_zerocopy.c b/tools/testing/selftests/net/msg_zerocopy.c index 7ea5fb28c93d..cf227f0011b5 100644 --- a/tools/testing/selftests/net/msg_zerocopy.c +++ b/tools/testing/selftests/net/msg_zerocopy.c @@ -66,6 +66,10 @@ #define SO_ZEROCOPY 60 #endif +#ifndef SCM_ZC_NOTIFICATION +#define SCM_ZC_NOTIFICATION 78 +#endif + #ifndef SO_EE_CODE_ZEROCOPY_COPIED #define SO_EE_CODE_ZEROCOPY_COPIED 1 #endif @@ -74,6 +78,14 @@ #define MSG_ZEROCOPY 0x4000000 #endif +#define ZC_INFO_ARR_SIZE (ZC_NOTIFICATION_MAX * sizeof(struct zc_info_elem)) +#define ZC_INFO_SIZE (sizeof(struct zc_info) + ZC_INFO_ARR_SIZE) + +enum notification_type { + MSG_ZEROCOPY_NOTIFY_ERRQUEUE = 1, + MSG_ZEROCOPY_NOTIFY_SENDMSG = 2, +}; + static int cfg_cork; static bool cfg_cork_mixed; static int cfg_cpu = -1; /* default: pin to last cpu */ @@ -86,7 +98,7 @@ static int cfg_runtime_ms = 4200; static int cfg_verbose; static int cfg_waittime_ms = 500; static int cfg_notification_limit = 32; -static bool cfg_zerocopy; +static enum notification_type cfg_zerocopy; static socklen_t cfg_alen; static struct sockaddr_storage cfg_dst_addr; @@ -97,6 +109,8 @@ static long packets, bytes, completions, expected_completions; static int zerocopied = -1; static uint32_t next_completion; static uint32_t sends_since_notify; +static char zc_ckbuf[CMSG_SPACE(ZC_INFO_SIZE)]; +static bool added_zcopy_info; static unsigned long gettimeofday_ms(void) { @@ -182,7 +196,26 @@ static void add_zcopy_cookie(struct msghdr *msg, uint32_t cookie) memcpy(CMSG_DATA(cm), &cookie, sizeof(cookie)); } -static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy, int domain) +static void add_zcopy_info(struct msghdr *msg) +{ + struct zc_info *zc_info; + struct cmsghdr *cm; + + if (!msg->msg_control) + error(1, errno, "NULL user arg"); + cm = (struct cmsghdr *)msg->msg_control; + cm->cmsg_len = CMSG_LEN(ZC_INFO_SIZE); + cm->cmsg_level = SOL_SOCKET; + cm->cmsg_type = SCM_ZC_NOTIFICATION; + + zc_info = (struct zc_info *)CMSG_DATA(cm); + zc_info->size = ZC_NOTIFICATION_MAX; + + added_zcopy_info = true; +} + +static bool do_sendmsg(int fd, struct msghdr *msg, + enum notification_type do_zerocopy, int domain) { int ret, len, i, flags; static uint32_t cookie; @@ -200,6 +233,12 @@ static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy, int domain) msg->msg_controllen = CMSG_SPACE(sizeof(cookie)); msg->msg_control = (struct cmsghdr *)ckbuf; add_zcopy_cookie(msg, ++cookie); + } else if (do_zerocopy == MSG_ZEROCOPY_NOTIFY_SENDMSG && + sends_since_notify + 1 >= cfg_notification_limit) { + memset(&msg->msg_control, 0, sizeof(msg->msg_control)); + msg->msg_controllen = CMSG_SPACE(ZC_INFO_SIZE); + msg->msg_control = (struct cmsghdr *)zc_ckbuf; + add_zcopy_info(msg); } } @@ -218,7 +257,7 @@ static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy, int domain) if (do_zerocopy && ret) expected_completions++; } - if (do_zerocopy && domain == PF_RDS) { + if (msg->msg_control) { msg->msg_control = NULL; msg->msg_controllen = 0; } @@ -466,6 +505,44 @@ static void do_recv_completions(int fd, int domain) sends_since_notify = 0; } +static void do_recv_completions2(void) +{ + struct cmsghdr *cm = (struct cmsghdr *)zc_ckbuf; + struct zc_info *zc_info; + __u32 hi, lo, range; + __u8 zerocopy; + int i; + + zc_info = (struct zc_info *)CMSG_DATA(cm); + for (i = 0; i < zc_info->size; i++) { + hi = zc_info->arr[i].hi; + lo = zc_info->arr[i].lo; + zerocopy = zc_info->arr[i].zerocopy; + range = hi - lo + 1; + + if (cfg_verbose && lo != next_completion) + fprintf(stderr, "gap: %u..%u does not append to %u\n", + lo, hi, next_completion); + next_completion = hi + 1; + + if (zerocopied == -1) { + zerocopied = zerocopy; + } else if (zerocopied != zerocopy) { + fprintf(stderr, "serr: inconsistent\n"); + zerocopied = zerocopy; + } + + completions += range; + sends_since_notify -= range; + + if (cfg_verbose >= 2) + fprintf(stderr, "completed: %u (h=%u l=%u)\n", + range, hi, lo); + } + + added_zcopy_info = false; +} + /* Wait for all remaining completions on the errqueue */ static void do_recv_remaining_completions(int fd, int domain) { @@ -553,11 +630,16 @@ static void do_tx(int domain, int type, int protocol) else do_sendmsg(fd, &msg, cfg_zerocopy, domain); - if (cfg_zerocopy && sends_since_notify >= cfg_notification_limit) + if (cfg_zerocopy == MSG_ZEROCOPY_NOTIFY_ERRQUEUE && + sends_since_notify >= cfg_notification_limit) do_recv_completions(fd, domain); + if (cfg_zerocopy == MSG_ZEROCOPY_NOTIFY_SENDMSG && + added_zcopy_info) + do_recv_completions2(); + while (!do_poll(fd, POLLOUT)) { - if (cfg_zerocopy) + if (cfg_zerocopy == MSG_ZEROCOPY_NOTIFY_ERRQUEUE) do_recv_completions(fd, domain); } @@ -715,7 +797,7 @@ static void parse_opts(int argc, char **argv) cfg_payload_len = max_payload_len; - while ((c = getopt(argc, argv, "46c:C:D:i:l:mp:rs:S:t:vz")) != -1) { + while ((c = getopt(argc, argv, "46c:C:D:i:l:mnp:rs:S:t:vz")) != -1) { switch (c) { case '4': if (cfg_family != PF_UNSPEC) @@ -749,6 +831,9 @@ static void parse_opts(int argc, char **argv) case 'm': cfg_cork_mixed = true; break; + case 'n': + cfg_zerocopy = MSG_ZEROCOPY_NOTIFY_SENDMSG; + break; case 'p': cfg_port = strtoul(optarg, NULL, 0); break; @@ -768,7 +853,7 @@ static void parse_opts(int argc, char **argv) cfg_verbose++; break; case 'z': - cfg_zerocopy = true; + cfg_zerocopy = MSG_ZEROCOPY_NOTIFY_ERRQUEUE; break; } } @@ -779,6 +864,8 @@ static void parse_opts(int argc, char **argv) error(1, 0, "-D required for PF_RDS\n"); if (!cfg_rx && !saddr) error(1, 0, "-S required for PF_RDS\n"); + if (cfg_zerocopy == MSG_ZEROCOPY_NOTIFY_SENDMSG) + error(1, 0, "PF_RDS does not support ZC_NOTIF_SENDMSG"); } setup_sockaddr(cfg_family, daddr, &cfg_dst_addr); setup_sockaddr(cfg_family, saddr, &cfg_src_addr); diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh index 89c22f5320e0..022a6936d86f 100755 --- a/tools/testing/selftests/net/msg_zerocopy.sh +++ b/tools/testing/selftests/net/msg_zerocopy.sh @@ -118,4 +118,5 @@ do_test() { do_test "${EXTRA_ARGS}" do_test "-z ${EXTRA_ARGS}" +do_test "-n ${EXTRA_ARGS}" echo ok