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,URIBL_BLOCKED,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 33D53C43603 for ; Wed, 11 Dec 2019 15:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 093B521556 for ; Wed, 11 Dec 2019 15:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576079407; bh=98Jbf77nAwt1fSG0qBVGdDEDkG9mLiiWzrCEKzaMeNg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UXVY5i1cBjnAqJBETbd+QtgOJr+4GcUd0zkbSJ9fFrj0qsjYpcZSI3QoKzRZO5N6D zw438hOvcYfYaIneR5ZA4LZCZVuHzmqfOzMN+rFtGtYn9q5xxsCJeKEQ80x2ntQC+c wfxm5MeBNPdwulKrmotgy9iGE7HSIueHuZkuzxy4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732780AbfLKPX7 (ORCPT ); Wed, 11 Dec 2019 10:23:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:55066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732620AbfLKPXy (ORCPT ); Wed, 11 Dec 2019 10:23:54 -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 64DCD2173E; Wed, 11 Dec 2019 15:23:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077833; bh=98Jbf77nAwt1fSG0qBVGdDEDkG9mLiiWzrCEKzaMeNg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0kAs7iDx+3D8fXHsVaNtp4+GIsWjHP1RRFOyPgwQxRZkwKNlAzxcwL9zFvKCa2CmJ 9zgFSc1OZ2azKb4/NryBDE//DYUkJYAsW6FH0pAcCQ5xK18iAmBtbOB/E1HjIaRcgO 11+zmwi/4vC1GKqJefARFBTcifx02ClibB1KbAf8= 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 , Sasha Levin Subject: [PATCH 4.19 187/243] IB/hfi1: Close VNIC sdma_progress sleep window Date: Wed, 11 Dec 2019 16:05:49 +0100 Message-Id: <20191211150351.796033556@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191211150339.185439726@linuxfoundation.org> References: <20191211150339.185439726@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: Mike Marciniszyn [ Upstream commit 18912c4524385dd6532c682cb9d4f6aa39ba8d47 ] 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 vnic_sdma xmit will hang. Fix by moving the lock to enclose the sdma_progress() call. Also, delete the tx_retry. The need for this was removed by: commit bcad29137a97 ("IB/hfi1: Serve the most starved iowait entry first") Fixes: 64551ede6cd1 ("IB/hfi1: VNIC SDMA support") Reviewed-by: Gary Leshner Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/hw/hfi1/vnic_sdma.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/vnic_sdma.c b/drivers/infiniband/hw/hfi1/vnic_sdma.c index c3c96c5869ed4..718dcdef946ee 100644 --- a/drivers/infiniband/hw/hfi1/vnic_sdma.c +++ b/drivers/infiniband/hw/hfi1/vnic_sdma.c @@ -57,7 +57,6 @@ #define HFI1_VNIC_TXREQ_NAME_LEN 32 #define HFI1_VNIC_SDMA_DESC_WTRMRK 64 -#define HFI1_VNIC_SDMA_RETRY_COUNT 1 /* * struct vnic_txreq - VNIC transmit descriptor @@ -67,7 +66,6 @@ * @pad: pad buffer * @plen: pad length * @pbc_val: pbc value - * @retry_count: tx retry count */ struct vnic_txreq { struct sdma_txreq txreq; @@ -77,8 +75,6 @@ struct vnic_txreq { unsigned char pad[HFI1_VNIC_MAX_PAD]; u16 plen; __le64 pbc_val; - - u32 retry_count; }; static void vnic_sdma_complete(struct sdma_txreq *txreq, @@ -196,7 +192,6 @@ int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx, ret = build_vnic_tx_desc(sde, tx, pbc); if (unlikely(ret)) goto free_desc; - tx->retry_count = 0; ret = sdma_send_txreq(sde, &vnic_sdma->wait, &tx->txreq, vnic_sdma->pkts_sent); @@ -238,14 +233,14 @@ static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde, struct hfi1_vnic_sdma *vnic_sdma = container_of(wait, struct hfi1_vnic_sdma, wait); struct hfi1_ibdev *dev = &vnic_sdma->dd->verbs_dev; - struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq); - if (sdma_progress(sde, seq, txreq)) - if (tx->retry_count++ < HFI1_VNIC_SDMA_RETRY_COUNT) - return -EAGAIN; + write_seqlock(&dev->iowait_lock); + if (sdma_progress(sde, seq, txreq)) { + write_sequnlock(&dev->iowait_lock); + return -EAGAIN; + } vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED; - write_seqlock(&dev->iowait_lock); if (list_empty(&vnic_sdma->wait.list)) iowait_queue(pkts_sent, wait, &sde->dmawait); write_sequnlock(&dev->iowait_lock); -- 2.20.1