From patchwork Mon Feb 11 16:23:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 10806211 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C8A2913B5 for ; Mon, 11 Feb 2019 16:23:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B2B5228111 for ; Mon, 11 Feb 2019 16:23:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A626328538; Mon, 11 Feb 2019 16:23:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C39920246 for ; Mon, 11 Feb 2019 16:23:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726941AbfBKQX5 (ORCPT ); Mon, 11 Feb 2019 11:23:57 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:50993 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726892AbfBKQX5 (ORCPT ); Mon, 11 Feb 2019 11:23:57 -0500 Received: by mail-it1-f195.google.com with SMTP id z7so27806292iti.0; Mon, 11 Feb 2019 08:23:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=th1O/wngdFHrunVx5REJASdpDp11bszNdXSRvbqxJFo=; b=P0MEPWSc7/Ux/owdLMthOmTwoAhjyBZy1ESm91k9wanj30NspTeDmD2tSbJGh5SCpb tFhvd1JI2JPc7QmkUIhqZ91EiQ9mhzZSac03UcWE6i5y89K6GzlNHt/BCjGZ7didMKaB 1K0/ML7SJC2gnIlI3lPvuEaAmWne6JR/NCjAdVP96tKSO8XbJ6er1xIgUuvm6S8hjIWv nVQz3WmthC14mjHJ9e9ZzOytpTt5zmULubUNEn0y1izYrMzFTngM0fxUlIkE0uBEXkFi LwnSsyJ1L19itA/wPF94ViTjnOf4eOCg/CjN5L1uSdkDQUvZRcFcjcozeiR6ZinQi73x xItg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:from:to:cc:date:message-id :in-reply-to:references:user-agent:mime-version :content-transfer-encoding; bh=th1O/wngdFHrunVx5REJASdpDp11bszNdXSRvbqxJFo=; b=BePkmil7jCE7jghlzeC29OTGRjD/I+GGkkGuyTcRPj1N4wukeC22myJYyszkgJL438 OKO+NQiCT97STcG5tkW8SZon4EJh2zsqYaKvB1mpjsBLRKm1/yLyPQqaALaWaWX54xQ3 qoWgb3fVfP373DJb+N51HEr8upt1/792jwNN9ls2RrIBdflg08hPXYQPkZpU7nbDjemN rreoJhh3f7PMH84xvJqHISFs0PTejcvls2Mc+unbobuyjgIXWnj0bseY9UBDu9QDLcYK pJXTJzMsTDnmU/5fiLUlf47ZpF0tDtAPkFY14yAscA8O+5dYFCQuABuDAVoWfPUhwe3e +DBA== X-Gm-Message-State: AHQUAuaM93wJxgf5/EgTREM3cumTT4EnNbglPyLCQfvQ1Bo3MSeME8JD UI/3ER1CZV/9fq4WEYO5N+8= X-Google-Smtp-Source: AHgI3IYinLotN5mo1DmV1c4QoD530pgtRvAEqi6bB4szK3CZQ8xFFEgwbtTGYd2PDlmLpEjvkPowUA== X-Received: by 2002:a6b:ef0b:: with SMTP id k11mr20718390ioh.186.1549902236296; Mon, 11 Feb 2019 08:23:56 -0800 (PST) Received: from gateway.1015granger.net (c-68-61-232-219.hsd1.mi.comcast.net. [68.61.232.219]) by smtp.gmail.com with ESMTPSA id s4sm4505684iom.83.2019.02.11.08.23.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 08:23:55 -0800 (PST) Received: from manet.1015granger.net (manet.1015granger.net [192.168.1.51]) by gateway.1015granger.net (8.14.7/8.14.7) with ESMTP id x1BGNsXt029961; Mon, 11 Feb 2019 16:23:54 GMT Subject: [PATCH v1 03/23] xprtrdma: Reduce the doorbell rate (Receive) From: Chuck Lever To: anna.schumaker@netapp.com Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 11 Feb 2019 11:23:54 -0500 Message-ID: <20190211162354.2817.81043.stgit@manet.1015granger.net> In-Reply-To: <20190211161920.2817.20881.stgit@manet.1015granger.net> References: <20190211161920.2817.20881.stgit@manet.1015granger.net> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Post RECV WRs in batches to reduce the hardware doorbell rate per transport. This helps the RPC-over-RDMA client scale better in number of transports. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 2 ++ net/sunrpc/xprtrdma/xprt_rdma.h | 10 ++++++++++ 2 files changed, 12 insertions(+) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 4994e75..b4e997d 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1480,6 +1480,8 @@ struct rpcrdma_regbuf * if (ep->rep_receive_count > needed) goto out; needed -= ep->rep_receive_count; + if (!temp) + needed += RPCRDMA_MAX_RECV_BATCH; count = 0; wr = NULL; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 33db208..10f6593 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -205,6 +205,16 @@ struct rpcrdma_rep { struct ib_recv_wr rr_recv_wr; }; +/* To reduce the rate at which a transport invokes ib_post_recv + * (and thus the hardware doorbell rate), xprtrdma posts Receive + * WRs in batches. + * + * Setting this to zero disables Receive post batching. + */ +enum { + RPCRDMA_MAX_RECV_BATCH = 7, +}; + /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes */ struct rpcrdma_req;