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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 31097C433FE for ; Wed, 9 Dec 2020 15:23:22 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E14F223AA8 for ; Wed, 9 Dec 2020 15:23:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E14F223AA8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6112F6EA83; Wed, 9 Dec 2020 15:23:21 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id B9FDA6EA83 for ; Wed, 9 Dec 2020 15:23:19 +0000 (UTC) IronPort-SDR: MSgLydGINz4+JqBal1u8yiW3sZs9BhkmpYOsnqegx6cGqdKgyOk41EBnGlcyydX4ESe0HebxKk Gz9bzFAruyhA== X-IronPort-AV: E=McAfee;i="6000,8403,9829"; a="174237034" X-IronPort-AV: E=Sophos;i="5.78,405,1599548400"; d="scan'208";a="174237034" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2020 07:23:18 -0800 IronPort-SDR: 1S1huRtCFlmDa6GeDquoK2EQIhcRktyUWEegVBDfLwWBrlyt9f/MjyJlv4IeWzrccI2ZpZnL+r cHj41CAbv8zA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,405,1599548400"; d="scan'208";a="318813010" Received: from gaia.fi.intel.com ([10.237.72.192]) by fmsmga007.fm.intel.com with ESMTP; 09 Dec 2020 07:23:17 -0800 Received: by gaia.fi.intel.com (Postfix, from userid 1000) id 7A4E25C2003; Wed, 9 Dec 2020 17:21:02 +0200 (EET) From: Mika Kuoppala To: Chris Wilson , intel-gfx@lists.freedesktop.org In-Reply-To: <20201208231834.24812-1-chris@chris-wilson.co.uk> References: <20201208231834.24812-1-chris@chris-wilson.co.uk> Date: Wed, 09 Dec 2020 17:21:02 +0200 Message-ID: <87zh2nkntt.fsf@gaia.fi.intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [PATCH 1/3] drm/i915: Remove livelock from "do_idle_maps" vtd w/a X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chris Wilson Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Chris Wilson writes: > A call to wait for the GT to idle from inside the put_pages fallback is > prone to cause an uninterruptible livelock. As it does not provide > adequate serialisation with new requests, simply fallback to a trial s/trial/trivial > sleep. > > Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala > --- > drivers/gpu/drm/i915/i915_gem_gtt.c | 25 ++++++++++--------------- > 1 file changed, 10 insertions(+), 15 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c > index c5ee1567f3d1..d2350a4c6606 100644 > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c > @@ -55,22 +55,17 @@ int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj, > void i915_gem_gtt_finish_pages(struct drm_i915_gem_object *obj, > struct sg_table *pages) > { > - struct drm_i915_private *dev_priv = to_i915(obj->base.dev); > - struct device *kdev = &dev_priv->drm.pdev->dev; > - struct i915_ggtt *ggtt = &dev_priv->ggtt; > - > - if (unlikely(ggtt->do_idle_maps)) { > - /* XXX This does not prevent more requests being submitted! */ > - if (intel_gt_retire_requests_timeout(ggtt->vm.gt, > - -MAX_SCHEDULE_TIMEOUT)) { > - drm_err(&dev_priv->drm, > - "Failed to wait for idle; VT'd may hang.\n"); > - /* Wait a bit, in hopes it avoids the hang */ > - udelay(10); > - } > - } > + struct drm_i915_private *i915 = to_i915(obj->base.dev); > + struct i915_ggtt *ggtt = &i915->ggtt; > + > + /* XXX This does not prevent more requests being submitted! */ > + if (unlikely(ggtt->do_idle_maps)) > + /* Wait a bit, in hope it avoids the hang */ > + usleep_range(100, 250); > > - dma_unmap_sg(kdev, pages->sgl, pages->nents, PCI_DMA_BIDIRECTIONAL); > + dma_unmap_sg(&i915->drm.pdev->dev, > + pages->sgl, pages->nents, > + PCI_DMA_BIDIRECTIONAL); > } > > /** > -- > 2.20.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx