From patchwork Mon Jun 24 20:17:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Marciniszyn, Mike" X-Patchwork-Id: 11014059 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 C10211398 for ; Mon, 24 Jun 2019 20:17:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B049C28A3F for ; Mon, 24 Jun 2019 20:17:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A4E4828A56; Mon, 24 Jun 2019 20:17:50 +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=-7.9 required=2.0 tests=BAYES_00,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 9057128A3F for ; Mon, 24 Jun 2019 20:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729656AbfFXURt (ORCPT ); Mon, 24 Jun 2019 16:17:49 -0400 Received: from mga06.intel.com ([134.134.136.31]:55101 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727089AbfFXURs (ORCPT ); Mon, 24 Jun 2019 16:17:48 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jun 2019 13:17:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,413,1557212400"; d="scan'208";a="166438674" Received: from sedona.ch.intel.com ([10.2.136.157]) by orsmga006.jf.intel.com with ESMTP; 24 Jun 2019 13:17:47 -0700 Received: from awfm-01.aw.intel.com (awfm-01.aw.intel.com [10.228.212.213]) by sedona.ch.intel.com (8.14.3/8.14.3/Standard MailSET/Hub) with ESMTP id x5OKHlR1023322; Mon, 24 Jun 2019 13:17:47 -0700 Received: from awfm-01.aw.intel.com (localhost [127.0.0.1]) by awfm-01.aw.intel.com (8.14.7/8.14.7) with ESMTP id x5OKHaIt170385; Mon, 24 Jun 2019 16:17:36 -0400 Subject: [PATCH] IB/hfi1: Close PSM sdma_progress sleep window To: stable@vger.kernel.org From: Mike Marciniszyn Cc: linux-rdma@vger.kernel.org, stable-commits@vger.kernel.org Date: Mon, 24 Jun 2019 16:17:36 -0400 Message-ID: <20190624201735.170363.43524.stgit@awfm-01.aw.intel.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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") Ported to linux-4.14.y. 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 --- drivers/infiniband/hw/hfi1/user_sdma.c | 12 ++++-------- drivers/infiniband/hw/hfi1/user_sdma.h | 1 - 2 files changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c index cbe5ab2..75275f9 100644 --- a/drivers/infiniband/hw/hfi1/user_sdma.c +++ b/drivers/infiniband/hw/hfi1/user_sdma.c @@ -132,25 +132,22 @@ 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)) iowait_queue(pkts_sent, &pq->busy, &sde->dmawait); write_sequnlock(&dev->iowait_lock); return -EBUSY; eagain: + write_sequnlock(&dev->iowait_lock); return -EAGAIN; } @@ -803,7 +800,6 @@ static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts) tx->flags = 0; tx->req = req; - tx->busycount = 0; INIT_LIST_HEAD(&tx->list); /* diff --git a/drivers/infiniband/hw/hfi1/user_sdma.h b/drivers/infiniband/hw/hfi1/user_sdma.h index 2b5326d..87b0c56 100644 --- a/drivers/infiniband/hw/hfi1/user_sdma.h +++ b/drivers/infiniband/hw/hfi1/user_sdma.h @@ -236,7 +236,6 @@ struct user_sdma_txreq { struct list_head list; struct user_sdma_request *req; u16 flags; - unsigned int busycount; u64 seqnum; };