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=BAYES_00,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 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 98CD8C433E1 for ; Thu, 20 Aug 2020 08:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65B8C207FB for ; Thu, 20 Aug 2020 08:32:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597912345; bh=4GQ1kegTsCwm6W7wqEajIc4JzVWkP9hyrXR8P+b3qTs=; h=Subject:To:Cc:From:Date:List-ID:From; b=euXAj7kX/YHOQfyFtoMmm3cGXWdz4tIv99M5WCTrf/cBoU/jEOwKG0DU3160EUocg gNniOHl0htbKuLiXmMKiI/WVyVL9OeVuzWw47x4X8VJdim4ITrUPpkwVCSHLTOgvSW dtTfD/mbJ/VwS/VKHGSlhvPb2zcfL8jaJ6Cw89JE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726772AbgHTIcX (ORCPT ); Thu, 20 Aug 2020 04:32:23 -0400 Received: from forward2-smtp.messagingengine.com ([66.111.4.226]:53371 "EHLO forward2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726781AbgHTIcI (ORCPT ); Thu, 20 Aug 2020 04:32:08 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailforward.nyi.internal (Postfix) with ESMTP id 49D691941F75; Thu, 20 Aug 2020 04:31:04 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Thu, 20 Aug 2020 04:31:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=lb+LHR OSS9D1Xr0GFYi3tFEvDuMRLOz9Sfwe/7XoVFA=; b=aULWrlf6z+e01oAT8HpL43 8UQD3uX7spXRr6wBh5L18W5DYoyg7w8INz63JJco5TxTcs9iaEa5wqyevIPQvNvH ZzJhl6JruF7NRl1LUsCKPSw6iAVEEw8cdJNd/g2ZfrRPWN94igT8DtQ9PbFbeU0e S3+LOl1Fu6SRpYQMo1lgorChNOSMLflOJX80oUHeYhHKOhegdZz3KJqPHoQn+GkS CAQ8NzFbaB5NnMisMzBn9b/qa+MYIEHj3xl1SsbJNgpqExaq4ggf1Pk4cmqKmRne ZpBZ132zfV6es6PPvSGKYazeptt9Ofz1B+9K/jGqLwqJidqVtPPztSzwyJW2Jbsg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduiedruddutddgtddvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepkefhhfefgfefheeffedugeeuvddvvefggffftdduue ejhffhgfevuedtvddtjefgnecuffhomhgrihhnpehfrhgvvgguvghskhhtohhprdhorhhg necukfhppeekfedrkeeirdekledruddtjeenucevlhhushhtvghrufhiiigvpedvnecurf grrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomh X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id C3DAD30600B1; Thu, 20 Aug 2020 04:31:03 -0400 (EDT) Subject: FAILED: patch "[PATCH] drm/i915: Skip signaling a signaled request" failed to apply to 5.4-stable tree To: chris@chris-wilson.co.uk, stable@vger.kernel.org, tvrtko.ursulin@intel.com, venkata.ramana.nayana@intel.com Cc: From: Date: Thu, 20 Aug 2020 10:31:24 +0200 Message-ID: <159791228474200@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1d9221e9d395c8c80d99d002bea3c9b6dd192d6a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 13 Jul 2020 15:16:36 +0100 Subject: [PATCH] drm/i915: Skip signaling a signaled request Preempt-to-busy introduces various fascinating complications in that the requests may complete as we are unsubmitting them from HW. As they may then signal after unsubmission, we may find ourselves having to cleanup the signaling request from within the signaling callback. This causes us to recurse onto the same i915_request.lock. However, if the request is already signaled (as it will be before we enter the signal callbacks), we know we can skip the signaling of that request during submission, neatly evading the spinlock recursion. unsubmit(ve.rq0) # timeslice expiration or other preemption -> virtual_submit_request(ve.rq0) dma_fence_signal(ve.rq0) # request completed before preemption ack -> submit_notify(ve.rq1) -> virtual_submit_request(ve.rq1) # sees that we have completed ve.rq0 -> __i915_request_submit(ve.rq0) [ 264.210142] BUG: spinlock recursion on CPU#2, sample_multi_tr/2093 [ 264.210150] lock: 0xffff9efd6ac55080, .magic: dead4ead, .owner: sample_multi_tr/2093, .owner_cpu: 2 [ 264.210155] CPU: 2 PID: 2093 Comm: sample_multi_tr Tainted: G U [ 264.210158] Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWR1.R00.X212.B01.1909060036 09/06/2019 [ 264.210160] Call Trace: [ 264.210167] dump_stack+0x98/0xda [ 264.210174] spin_dump.cold+0x24/0x3c [ 264.210178] do_raw_spin_lock+0x9a/0xd0 [ 264.210184] _raw_spin_lock_nested+0x6a/0x70 [ 264.210314] __i915_request_submit+0x10a/0x3c0 [i915] [ 264.210415] virtual_submit_request+0x9b/0x380 [i915] [ 264.210516] submit_notify+0xaf/0x14c [i915] [ 264.210602] __i915_sw_fence_complete+0x8a/0x230 [i915] [ 264.210692] i915_sw_fence_complete+0x2d/0x40 [i915] [ 264.210762] __dma_i915_sw_fence_wake+0x19/0x30 [i915] [ 264.210767] dma_fence_signal_locked+0xb1/0x1c0 [ 264.210772] dma_fence_signal+0x29/0x50 [ 264.210871] i915_request_wait+0x5cb/0x830 [i915] [ 264.210876] ? dma_resv_get_fences_rcu+0x294/0x5d0 [ 264.210974] i915_gem_object_wait_fence+0x2f/0x40 [i915] [ 264.211084] i915_gem_object_wait+0xce/0x400 [i915] [ 264.211178] i915_gem_wait_ioctl+0xff/0x290 [i915] Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") References: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: "Nayana, Venkata Ramana" Cc: # v5.4+ Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20200713141636.29326-1-chris@chris-wilson.co.uk diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index d907d538176e..91786310c114 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -314,13 +314,18 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) { lockdep_assert_held(&rq->lock); + if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags)) + return true; + if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags)) { struct intel_breadcrumbs *b = &rq->engine->breadcrumbs; struct intel_context *ce = rq->context; struct list_head *pos; spin_lock(&b->irq_lock); - GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)); + + if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) + goto unlock; if (!__intel_breadcrumbs_arm_irq(b)) goto unlock; diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 3bb7320249ae..0b2fe55e6194 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -560,22 +560,25 @@ bool __i915_request_submit(struct i915_request *request) engine->serial++; result = true; -xfer: /* We may be recursing from the signal callback of another i915 fence */ - spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING); - +xfer: if (!test_and_set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags)) { list_move_tail(&request->sched.link, &engine->active.requests); clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); - __notify_execute_cb(request); } - GEM_BUG_ON(!llist_empty(&request->execute_cb)); - if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags) && - !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &request->fence.flags) && - !i915_request_enable_breadcrumb(request)) - intel_engine_signal_breadcrumbs(engine); + /* We may be recursing from the signal callback of another i915 fence */ + if (!i915_request_signaled(request)) { + spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING); + + __notify_execute_cb(request); + if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, + &request->fence.flags) && + !i915_request_enable_breadcrumb(request)) + intel_engine_signal_breadcrumbs(engine); - spin_unlock(&request->lock); + spin_unlock(&request->lock); + GEM_BUG_ON(!llist_empty(&request->execute_cb)); + } return result; }