From patchwork Sun Mar 24 13:55:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13600821 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (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 D5C1E374FC; Sun, 24 Mar 2024 13:55:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711288559; cv=none; b=n+Cp9xa4yLzzSHSrwvUBD6Y3cNeFLV9wchTcDPAIaAlklXlmvzU/ims0hgTQJTSdj9Z08U2UqnJUfXzWFB+Y38GYP3T7/BLIKhqWRBP/2TJ5CPfUpsc5nUTYlW+g5mV5N4Dnd2TzjG0thaArOJ/pB5KiBgx1F/bOgfm9jBltx54= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711288559; c=relaxed/simple; bh=+l8zWQElahWaPkmyYvk6aEolLdDlyQu2GF741usRILk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TLgiDfQLgAYQBXM+vNAyo1S3c8lVWguHgjI5Wlx1xhWHRunrFfo/DgQCKus6ydTt+TggShM7Vrk0c6W3bGsIRjiNKIcd0u1imN7o0N5iEsrjWWqPNro6TRCMRMrJO/IWRyAK52iB0MG+RhIoLn22VDLvtlAdbylEg/4Y/C9ndb8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=eZHWjYjW; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="eZHWjYjW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1711288549; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=Nb2nmxeq5eLGuWB1JKOUkoCi1VXxe+Li0Jy9GmclvdY=; b=eZHWjYjWUOHM4FvD6iXM8ZEJkAtsdeUUOHiLVi1jYjI2kDBhzqgNzGwuNkjo6Gmi81SdneEc/z01KcOCfesJqZtKeFDO1KjqOL+qercMr2v0oUIKE3D9XuIeCZ3Nu5bmBlqhFtiN/D4dx8vFuRQGfYYclncOBB1j5qDg1oCY63s= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=19;SR=0;TI=SMTPD_---0W373cto_1711288546; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0W373cto_1711288546) by smtp.aliyun-inc.com; Sun, 24 Mar 2024 21:55:48 +0800 From: Wen Gu To: wintera@linux.ibm.com, twinkler@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, wenjia@linux.ibm.com, jaka@linux.ibm.com Cc: borntraeger@linux.ibm.com, svens@linux.ibm.com, alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [RFC PATCH net-next v5 10/11] net/smc: adapt cursor update when sndbuf and peer DMB are merged Date: Sun, 24 Mar 2024 21:55:21 +0800 Message-Id: <20240324135522.108564-11-guwen@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20240324135522.108564-1-guwen@linux.alibaba.com> References: <20240324135522.108564-1-guwen@linux.alibaba.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 X-Patchwork-State: RFC If the local sndbuf shares the same physical memory with peer DMB, the cursor update processing needs to be adapted to ensure that the data to be consumed won't be overwritten. So in this case, the fin_curs and sndbuf_space that were originally updated after sending the CDC message should be modified to not be update until the peer updates cons_curs. Signed-off-by: Wen Gu --- net/smc/smc_cdc.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 3c06625ceb20..5e95347ae497 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -18,6 +18,7 @@ #include "smc_tx.h" #include "smc_rx.h" #include "smc_close.h" +#include "smc_ism.h" /********************************** send *************************************/ @@ -255,6 +256,14 @@ int smcd_cdc_msg_send(struct smc_connection *conn) return rc; smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; + + if (smc_ism_support_dmb_nocopy(conn->lgr->smcd)) + /* if local sndbuf shares the same memory region with + * peer DMB, then don't update the tx_curs_fin + * and sndbuf_space until peer has consumed the data. + */ + return rc; + /* Calculate transmitted data and increment free send buffer space */ diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, &conn->tx_curs_sent); @@ -323,7 +332,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, { union smc_host_cursor cons_old, prod_old; struct smc_connection *conn = &smc->conn; - int diff_cons, diff_prod; + int diff_cons, diff_prod, diff_tx; smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); @@ -339,6 +348,29 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, atomic_add(diff_cons, &conn->peer_rmbe_space); /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ smp_mb__after_atomic(); + + /* if local sndbuf shares the same memory region with + * peer RMB, then update tx_curs_fin and sndbuf_space + * here since peer has already consumed the data. + */ + if (conn->lgr->is_smcd && + smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { + /* Calculate consumed data and + * increment free send buffer space. + */ + diff_tx = smc_curs_diff(conn->sndbuf_desc->len, + &conn->tx_curs_fin, + &conn->local_rx_ctrl.cons); + /* increase local sndbuf space and fin_curs */ + smp_mb__before_atomic(); + atomic_add(diff_tx, &conn->sndbuf_space); + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ + smp_mb__after_atomic(); + smc_curs_copy(&conn->tx_curs_fin, + &conn->local_rx_ctrl.cons, conn); + + smc_tx_sndbuf_nonfull(smc); + } } diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,