From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 4FAF934AAEE; Thu, 11 Sep 2025 19:48:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757620128; cv=none; b=YI38ZdQC9H0bC7ntIFbUQyaudeuBtlYwr5r/Ao0bd6DKKHSfYwSOYZ/LF8NzKbtMFtYm6OKtUHvhFTYhU6io5wV13E0YZ9XRRkU2qPoZFSr44guKEhaXHBp831EIfHFQdl4m+0h0KbKunPUWw8c9gsA7OS10IRqhk8zDCSvc3Bw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757620128; c=relaxed/simple; bh=//5LKvuMS1Tj5yyuELe9SsMD+jiLG3M30BoJXUJDPv4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZiH8wVDVDAUa8cD8oJxLMi+Mv2Iu4uh59gdQxB5xlJPtkx3OTx9MF7ilInlG9OiLBzpr7C2a+MLwaEQ1GsFhWx19ga+sPwsqySsIbXHQthchyYhChQ3LdUHYbfnfgDIWmjKBVsSSu71JM98uIQnruhHzuD3xoB/9MofSBJpnbW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=jzVaSsBF; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="jzVaSsBF" Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 58BIIBXa009648; Thu, 11 Sep 2025 19:48:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=O/mmUSkPzZSNxYho4 c3x/XEs9uNbKZIkzoHVRwGcvLU=; b=jzVaSsBFQSsZ+FVwD4FoyyjmdJ7p7o01E zXMIE8G0ATYCAWvm35A0ZeTP/6HD5bpmcQleSbkmFyQQyuI1V/aZC9L3vhDxb5zC wrYetbtxrl/Cjj+HR/Ty+NiqJi19uuUpinj4ntU63ZKm7Ktpj5p2eQDAglHLAFkz 4FDIjjNyr7KcXhnW4ZB9dS1g0j8C8ytk0TRG63O2sFyOhVt39t3cq/SVGqsRShEQ PRFZnmFuTAHYfIugS2XHcZBCyjBRY94GbNP+Tw0r76733coaF5ncBRW7AOQHa70r n8FO3A6P3vv1jU7/enS8UxIz3n0FoTMBCLVL9PoOL136tXNpTs9XA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 490xydbu9a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 11 Sep 2025 19:48:34 +0000 (GMT) Received: from m0356517.ppops.net (m0356517.ppops.net [127.0.0.1]) by pps.reinject (8.18.1.12/8.18.0.8) with ESMTP id 58BJii9d007794; Thu, 11 Sep 2025 19:48:33 GMT Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 490xydbu92-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 11 Sep 2025 19:48:33 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 58BH6DUC020469; Thu, 11 Sep 2025 19:48:32 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 490yp17myu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 11 Sep 2025 19:48:32 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 58BJmSLJ51118530 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Sep 2025 19:48:28 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0349820043; Thu, 11 Sep 2025 19:48:28 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E082B20040; Thu, 11 Sep 2025 19:48:27 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTPS; Thu, 11 Sep 2025 19:48:27 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 55271) id A6F76E12C2; Thu, 11 Sep 2025 21:48:27 +0200 (CEST) From: Alexandra Winter To: "D. Wythe" , Dust Li , Sidraya Jayagond , Wenjia Zhang , David Miller , Jakub Kicinski , Paolo Abeni , Eric Dumazet , Andrew Lunn Cc: Julian Ruess , Aswin Karuvally , Halil Pasic , Mahanta Jambigi , Tony Lu , Wen Gu , linux-rdma@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Simon Horman , Eric Biggers , Ard Biesheuvel , Herbert Xu , Harald Freudenberger , Konstantin Shkolnyy Subject: [PATCH net-next v2 02/14] net/smc: Decouple sf and attached send_buf in smc_loopback Date: Thu, 11 Sep 2025 21:48:15 +0200 Message-ID: <20250911194827.844125-3-wintera@linux.ibm.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250911194827.844125-1-wintera@linux.ibm.com> References: <20250911194827.844125-1-wintera@linux.ibm.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: cjqGc-dNE6K5_BREmDSZ-cp6jjyx3GHj X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTA2MDIzNSBTYWx0ZWRfXwycB2JRusY0U KkX8z8t2w+Sio5C0N3GJPbDDVFsF5f3NJs5H7HnO6lI5GvAGmTun3hHSZj/f+V7g7KxT8E7YdS3 oDdhmT7ed19NfVDnWR90B896dyaVMV8OseRN+TegO9Jjq948S/Q3ahiyYW+x8XRUfvWn/+pQi30 gqVA3OkRBzZSdqYw7IJp+idiZmO0lbwwbwAkDECtj3in+lDpXMLPeQ0zvBUauvD608hvLnM/7j0 oLVsROJfbaIdojKieGhSjXV8UzcEhP6ZaJaf1wspiGowefqj3vva/bB9aOE23joV/9gGWtW64cR aEFUBWNDvmrCc5GBYag+ANvNXLsDpfrovUh1Kuq0rM1/K1AqcyNbCMnG40BNu/hFumXzy8Fm90g Jru4X6xT X-Proofpoint-GUID: _0EMapXhkOnaCSPabcz1mpKgM0MQt05i X-Authority-Analysis: v=2.4 cv=F59XdrhN c=1 sm=1 tr=0 ts=68c32792 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=yJojWOMRYYMA:10 a=VnNF1IyMAAAA:8 a=SRrdq9N9AAAA:8 a=YPWO3w2s4X-KU5j4784A:9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-11_03,2025-09-11_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 clxscore=1015 impostorscore=0 bulkscore=0 adultscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2509060235 Before this patch there was the following assumption in smc_loopback.c>smc_lo_move_data(): sf (signalling flag) == 0 : data is already in an attached target dmb sf == 1 : data is not yet in the target dmb This is true for the 2 callers in smc client smcd_cdc_msg_send() : sf=1 smcd_tx_rdma_writes() : sf=0 but should not be a general assumption. Add a bool to struct smc_buf_desc to indicate whether an SMC-D sndbuf_desc is an attached buffer. Don't call move_data() for attached send_buffers, because it is not necessary. Move the data in smc_lo_move_data() if len != 0 and signal when requested. Signed-off-by: Alexandra Winter Reviewed-by: Mahanta Jambigi Reviewed-by: Dust Li --- net/smc/smc_core.h | 5 +++++ net/smc/smc_ism.c | 1 + net/smc/smc_loopback.c | 9 +++------ net/smc/smc_tx.c | 3 +++ 4 files changed, 12 insertions(+), 6 deletions(-) diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 48a1b1dcb576..a5a78cbff341 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -13,6 +13,7 @@ #define _SMC_CORE_H #include +#include #include #include #include @@ -221,6 +222,10 @@ struct smc_buf_desc { /* virtually contiguous */ }; struct { /* SMC-D */ + /* SMC-D tx buffer */ + bool is_attached; + /* no need for explicit writes */ + /* SMC-D rx buffer: */ unsigned short sba_idx; /* SBA index number */ u64 token; diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c index fca01b95b65a..503a9f93b392 100644 --- a/net/smc/smc_ism.c +++ b/net/smc/smc_ism.c @@ -274,6 +274,7 @@ int smc_ism_attach_dmb(struct smcd_dev *dev, u64 token, dmb_desc->cpu_addr = dmb.cpu_addr; dmb_desc->dma_addr = dmb.dma_addr; dmb_desc->len = dmb.dmb_len; + dmb_desc->is_attached = true; } return rc; } diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c index 0eb00bbefd17..1853c26fbbbb 100644 --- a/net/smc/smc_loopback.c +++ b/net/smc/smc_loopback.c @@ -224,12 +224,6 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, struct smc_lo_dev *ldev = smcd->priv; struct smc_connection *conn; - if (!sf) - /* since sndbuf is merged with peer DMB, there is - * no need to copy data from sndbuf to peer DMB. - */ - return 0; - read_lock_bh(&ldev->dmb_ht_lock); hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_tok) { if (tmp_node->token == dmb_tok) { @@ -244,6 +238,9 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, memcpy((char *)rmb_node->cpu_addr + offset, data, size); read_unlock_bh(&ldev->dmb_ht_lock); + if (!sf) + return 0; + conn = smcd->conn[rmb_node->sba_idx]; if (!conn || conn->killed) return -EPIPE; diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 214ac3cbcf9a..3144b4b1fe29 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -426,6 +426,9 @@ static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, int srcchunk, dstchunk; int rc; + if (conn->sndbuf_desc->is_attached) + return 0; + for (dstchunk = 0; dstchunk < 2; dstchunk++) { for (srcchunk = 0; srcchunk < 2; srcchunk++) { void *data = conn->sndbuf_desc->cpu_addr + src_off; -- 2.48.1