From patchwork Mon Jun 3 03:00:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guangguan Wang X-Patchwork-Id: 13683224 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-99.freemail.mail.aliyun.com (out30-99.freemail.mail.aliyun.com [115.124.30.99]) (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 982B68F72; Mon, 3 Jun 2024 03:00:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.99 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717383632; cv=none; b=hzSXt9UhyCpzldcF5UOZeImYequO+niw2criMeoG3lufUWwZjdw9pwTQV71WibcmCywA2mKSXLsNLcv8C8XTE7grlYFJE287+6HddD3cxsvnkAwPWdeCxhUDuedsJn4D9kle112iLATtmK8kQ9I6Ln4qskyqewF1SdMinJP6f38= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717383632; c=relaxed/simple; bh=lugJqSJ1/XUwiPdotA8v7i7A6PAzS0bTvnu+1nr0uCk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TBKhjQbCPA6kKHagELsYfe1/tk4UOgyO7c64tajZr4NPmdL3F7V6o/YzfkNu997UU2EAHj9XSpg1Ld50nCJ2Hg68/VdrwxrELxL27t88uiJ6XRRHR8XiY7W4H8IOhrw6n6iy4SxW3/ELWjlKB74vAWWRaU1ljJuIeohiy12ACMs= 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=d6kT8xAZ; arc=none smtp.client-ip=115.124.30.99 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="d6kT8xAZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1717383628; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=c8Qrefu5m5AiWDhNk1XblbhGEG6YihUTmhwULb3d7Ck=; b=d6kT8xAZmdam3huNTuqTvHIkBxpS+8xxIZgSt8fL1br02/0QFmiZd5rX0b00CXkX9BHsy/C/uLd/Muz/bVsSx5ZZjJbTi9IN2ZZxgJkYIDyz0vKU3vOIismp53PPbKDE8HhnlIYiohJ96WKuG0RqIssYDv8f+bttpqzOq2Evxk4= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R761e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033022160150;MF=guangguan.wang@linux.alibaba.com;NM=1;PH=DS;RN=13;SR=0;TI=SMTPD_---0W7gQbUV_1717383627; Received: from localhost.localdomain(mailfrom:guangguan.wang@linux.alibaba.com fp:SMTPD_---0W7gQbUV_1717383627) by smtp.aliyun-inc.com; Mon, 03 Jun 2024 11:00:27 +0800 From: Guangguan Wang To: wenjia@linux.ibm.com, jaka@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: kgraul@linux.ibm.com, alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v2 2/2] net/smc: change SMCR_RMBE_SIZES from 5 to 15 Date: Mon, 3 Jun 2024 11:00:19 +0800 Message-Id: <20240603030019.91346-3-guangguan.wang@linux.alibaba.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20240603030019.91346-1-guangguan.wang@linux.alibaba.com> References: <20240603030019.91346-1-guangguan.wang@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 SMCR_RMBE_SIZES is the upper boundary of SMC-R's snd_buf and rcv_buf. The maximum bytes of snd_buf and rcv_buf can be calculated by 2^SMCR_ RMBE_SIZES * 16KB. SMCR_RMBE_SIZES = 5 means the upper boundary is 512KB. TCP's snd_buf and rcv_buf max size is configured by net.ipv4.tcp_w/rmem[2] whose default value is 4MB or 6MB, is much larger than SMC-R's upper boundary. In some scenarios, such as Recommendation System, the communication pattern is mainly large size send/recv, where the size of snd_buf and rcv_buf greatly affects performance. Due to the upper boundary disadvantage, SMC-R performs poor than TCP in those scenarios. So it is time to enlarge the upper boundary size of SMC-R's snd_buf and rcv_buf, so that the SMC-R's snd_buf and rcv_buf can be configured to larger size for performance gain in such scenarios. The SMC-R rcv_buf's size will be transferred to peer by the field rmbe_size in clc accept and confirm message. The length of the field rmbe_size is four bits, which means the maximum value of SMCR_RMBE_SIZES is 15. In case of frequently adjusting the value of SMCR_RMBE_SIZES in different scenarios, set the value of SMCR_RMBE_SIZES to the maximum value 15, which means the upper boundary of SMC-R's snd_buf and rcv_buf is 512MB. As the real memory usage is determined by the value of net.smc.w/rmem, not by the upper boundary, set the value of SMCR_RMBE_SIZES to the maximum value has no side affects. Signed-off-by: Guangguan Wang Co-developed-by: Wen Gu Signed-off-by: Wen Gu --- net/smc/smc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index acca3b1a068f..3b95828d9976 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -2006,7 +2006,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) } #define SMCD_DMBE_SIZES 6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */ -#define SMCR_RMBE_SIZES 5 /* 0 -> 16KB, 1 -> 32KB, .. 5 -> 512KB */ +#define SMCR_RMBE_SIZES 15 /* 0 -> 16KB, 1 -> 32KB, .. 15 -> 512MB */ /* convert the RMB size into the compressed notation (minimum 16K, see * SMCD/R_DMBE_SIZES.