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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 81D78C4332B for ; Mon, 23 Mar 2020 10:09:30 +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 5E8E420769 for ; Mon, 23 Mar 2020 10:09:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E8E420769 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 E25FF89E47; Mon, 23 Mar 2020 10:09:29 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9486789E47 for ; Mon, 23 Mar 2020 10:09:28 +0000 (UTC) IronPort-SDR: k4Y+hjCscvb5i0M9sv24Jm4Vk7PKCL6LsEtiyE0jZFU1juUgiu4BHPtX6btGZ7MgrRiYMa7dHu OrFZrm6FRADw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2020 03:09:27 -0700 IronPort-SDR: imaaSIobRfap00Q6nnB73cjivlNc6QZZOUp5o7nroDSxJHTaYCdstPNHpX+SyDNupDVI4i6QxD vCjZzbhAQ89Q== X-IronPort-AV: E=Sophos;i="5.72,296,1580803200"; d="scan'208";a="419451347" Received: from unknown (HELO [10.252.47.179]) ([10.252.47.179]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2020 03:09:27 -0700 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20200323092841.22240-1-chris@chris-wilson.co.uk> <20200323092841.22240-2-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <06af04fa-80b8-abdb-4736-ed6e58ede79a@linux.intel.com> Date: Mon, 23 Mar 2020 10:09:24 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200323092841.22240-2-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 2/8] drm/i915: Avoid live-lock with i915_vma_parked() 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 23/03/2020 09:28, Chris Wilson wrote: > Abuse^W Take advantage that we know we are inside the GT wakeref and > that prevents any client execbuf from reopening the i915_vma in order to > claim all the vma to close without having to drop the spinlock to free > each one individually. By keeping the spinlock, we do not have to > restart if we run concurrently with i915_gem_free_objects -- which > causes them both to restart continually and make very very slow > progress. > > Closes: https://gitlab.freedesktop.org/drm/intel/issues/1361 > Fixes: 77853186e547 ("drm/i915: Claim vma while under closed_lock in i915_vma_parked()") > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/i915_vma.c | 29 ++++++++++++++--------------- > 1 file changed, 14 insertions(+), 15 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c > index 5b3efb43a8ef..08699fa069aa 100644 > --- a/drivers/gpu/drm/i915/i915_vma.c > +++ b/drivers/gpu/drm/i915/i915_vma.c > @@ -1097,6 +1097,7 @@ void i915_vma_release(struct kref *ref) > void i915_vma_parked(struct intel_gt *gt) > { > struct i915_vma *vma, *next; > + LIST_HEAD(closed); > > spin_lock_irq(>->closed_lock); > list_for_each_entry_safe(vma, next, >->closed_vma, closed_link) { > @@ -1108,28 +1109,26 @@ void i915_vma_parked(struct intel_gt *gt) > if (!kref_get_unless_zero(&obj->base.refcount)) > continue; > > - if (i915_vm_tryopen(vm)) { > - list_del_init(&vma->closed_link); > - } else { > + if (!i915_vm_tryopen(vm)) { > i915_gem_object_put(obj); > - obj = NULL; > + continue; > } > > - spin_unlock_irq(>->closed_lock); > + list_move(&vma->closed_link, &closed); > + } > + spin_unlock_irq(>->closed_lock); > > - if (obj) { > - __i915_vma_put(vma); > - i915_gem_object_put(obj); > - } > + /* As the GT is held idle, no vma can be reopened as we destroy them */ > + list_for_each_entry_safe(vma, next, &closed, closed_link) { > + struct drm_i915_gem_object *obj = vma->obj; > + struct i915_address_space *vm = vma->vm; > > - i915_vm_close(vm); > + INIT_LIST_HEAD(&vma->closed_link); > + __i915_vma_put(vma); > > - /* Restart after dropping lock */ > - spin_lock_irq(>->closed_lock); > - next = list_first_entry(>->closed_vma, > - typeof(*next), closed_link); > + i915_gem_object_put(obj); > + i915_vm_close(vm); > } > - spin_unlock_irq(>->closed_lock); > } > > static void __i915_vma_iounmap(struct i915_vma *vma) > Reviewed-by: Tvrtko Ursulin Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx