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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 4044CC606C1 for ; Mon, 8 Jul 2019 15:45:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19E18216E3 for ; Mon, 8 Jul 2019 15:45:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562600700; bh=FG0Fd4yCVaRhYLAoDH+EcpNxQWOhdpbmj1xXw0TZ748=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jkdO0PftgXDB94Af4SeeREDouJ4v6RH+g2uqTxtMglxBJfrFBgXYNjefBZxXCIiz4 21Jv7cAiEp2TZU9a8nchWXihk3dw0D6MTqTb9xica8Z1JB73N6fhSSTWK1Ek94mhp8 g+SkyulXzRYwZDQ2uQS9Uls+Ey9sj7dMB/KiaBX8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729493AbfGHPXA (ORCPT ); Mon, 8 Jul 2019 11:23:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:49764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388096AbfGHPW7 (ORCPT ); Mon, 8 Jul 2019 11:22:59 -0400 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 36B662166E; Mon, 8 Jul 2019 15:22:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599378; bh=FG0Fd4yCVaRhYLAoDH+EcpNxQWOhdpbmj1xXw0TZ748=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XGKRJEEO2lvY81DeFLprtjV6EdeLZa/GfRq5jtnDRmgYgHcFOSG83DgX5V690y+lz Sbgj/ve2f39TQ7f2os0vZ68y91KZj2jFKK6Tz6/ExxQrJLnlPxAHlPOuQE/Wg310bU r8JWKIFSkP6o6w8ufSMighsfImSE6cv+nMFOq9uA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gary Leshner , Mike Marciniszyn , Dennis Dalessandro , Jason Gunthorpe Subject: [PATCH 4.9 099/102] IB/hfi1: Close PSM sdma_progress sleep window Date: Mon, 8 Jul 2019 17:13:32 +0200 Message-Id: <20190708150531.607648948@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150525.973820964@linuxfoundation.org> References: <20190708150525.973820964@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mike Marciniszyn commit da9de5f8527f4b9efc82f967d29a583318c034c7 upstream. The call to sdma_progress() is called outside the wait lock. In this case, there is a race condition where sdma_progress() can return false and the sdma_engine can idle. If that happens, there will be no more sdma interrupts to cause the wakeup and the user_sdma xmit will hang. Fix by moving the lock to enclose the sdma_progress() call. Also, delete busycount. The need for this was removed by: commit bcad29137a97 ("IB/hfi1: Serve the most starved iowait entry first") Cc: Fixes: 7724105686e7 ("IB/hfi1: add driver files") Reviewed-by: Gary Leshner Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/hfi1/user_sdma.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) --- a/drivers/infiniband/hw/hfi1/user_sdma.c +++ b/drivers/infiniband/hw/hfi1/user_sdma.c @@ -260,7 +260,6 @@ struct user_sdma_txreq { struct list_head list; struct user_sdma_request *req; u16 flags; - unsigned busycount; u64 seqnum; }; @@ -323,25 +322,22 @@ static int defer_packet_queue( struct hfi1_user_sdma_pkt_q *pq = container_of(wait, struct hfi1_user_sdma_pkt_q, busy); struct hfi1_ibdev *dev = &pq->dd->verbs_dev; - struct user_sdma_txreq *tx = - container_of(txreq, struct user_sdma_txreq, txreq); - if (sdma_progress(sde, seq, txreq)) { - if (tx->busycount++ < MAX_DEFER_RETRY_COUNT) - goto eagain; - } + write_seqlock(&dev->iowait_lock); + if (sdma_progress(sde, seq, txreq)) + goto eagain; /* * We are assuming that if the list is enqueued somewhere, it * is to the dmawait list since that is the only place where * it is supposed to be enqueued. */ xchg(&pq->state, SDMA_PKT_Q_DEFERRED); - write_seqlock(&dev->iowait_lock); if (list_empty(&pq->busy.list)) list_add_tail(&pq->busy.list, &sde->dmawait); write_sequnlock(&dev->iowait_lock); return -EBUSY; eagain: + write_sequnlock(&dev->iowait_lock); return -EAGAIN; } @@ -925,7 +921,6 @@ static int user_sdma_send_pkts(struct us tx->flags = 0; tx->req = req; - tx->busycount = 0; INIT_LIST_HEAD(&tx->list); if (req->seqnum == req->info.npkts - 1)