From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C508C43603 for ; Mon, 16 Dec 2019 18:37:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5AD921582 for ; Mon, 16 Dec 2019 18:37:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576521463; bh=Fuzx3MD10UTEWpoIo+tb/rfAjkPW5zaJnqeC+50ff3g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1ze7yFnmc/It6u2cHNiRBBaO9qNr4xpPDNkBlL+VsV6aBndNxuZVKEEPw7yuYbuGq BROETeXMKZoXQ/+/ZwireYZaYAbjxRuKeSW9Mn5UGw7fL6/IzZimxjNRThwyZLCf03 luw8ICBi+Dw4VaPPBIyjMuunu7G+iLkHRNFcJOMs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730034AbfLPShm (ORCPT ); Mon, 16 Dec 2019 13:37:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:45320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728182AbfLPSGB (ORCPT ); Mon, 16 Dec 2019 13:06:01 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02FCC20700; Mon, 16 Dec 2019 18:05:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576519560; bh=Fuzx3MD10UTEWpoIo+tb/rfAjkPW5zaJnqeC+50ff3g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gk3dYV/kob478HhQqg0KBZUOoIux1OtmLuKRyVuV7qxvy1QZoLTTxTHcG8Ks4Q0fa J1+uKoAredTbnRVVnYuDAabz0TfAAP4f4oJCuynbQHtQGOIfqAv2JauZ7E7UQGyiWJ wsw3GU99sHn/8t1cSbvJln1QayZcziS53r/6E8oE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Karsten Graul , Ursula Braun , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 116/140] net/smc: do not wait under send_lock Date: Mon, 16 Dec 2019 18:49:44 +0100 Message-Id: <20191216174819.039049758@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174747.111154704@linuxfoundation.org> References: <20191216174747.111154704@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Karsten Graul [ Upstream commit 33f3fcc290671590821ff3c0c9396db1ec9b7d4c ] smc_cdc_get_free_slot() might wait for free transfer buffers when using SMC-R. This wait should not be done under the send_lock, which is a spin_lock. This fixes a cpu loop in parallel threads waiting for the send_lock. Signed-off-by: Karsten Graul Signed-off-by: Ursula Braun Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_tx.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 0ecbbdc337b82..62885a2781c9a 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -486,25 +486,23 @@ static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) struct smc_wr_buf *wr_buf; int rc; - spin_lock_bh(&conn->send_lock); rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend); if (rc < 0) { if (rc == -EBUSY) { struct smc_sock *smc = container_of(conn, struct smc_sock, conn); - if (smc->sk.sk_err == ECONNABORTED) { - rc = sock_error(&smc->sk); - goto out_unlock; - } + if (smc->sk.sk_err == ECONNABORTED) + return sock_error(&smc->sk); rc = 0; if (conn->alert_token_local) /* connection healthy */ mod_delayed_work(system_wq, &conn->tx_work, SMC_TX_WORK_DELAY); } - goto out_unlock; + return rc; } + spin_lock_bh(&conn->send_lock); if (!conn->local_tx_ctrl.prod_flags.urg_data_present) { rc = smc_tx_rdma_writes(conn); if (rc) { -- 2.20.1