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=-10.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 CC4FAC433E1 for ; Wed, 5 Aug 2020 15:05:38 +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 AE0F02312E for ; Wed, 5 Aug 2020 15:05:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE0F02312E 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 3B6718902B; Wed, 5 Aug 2020 15:05:38 +0000 (UTC) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id 92F196E7EC for ; Wed, 5 Aug 2020 15:05:36 +0000 (UTC) IronPort-SDR: pDFvvHREVchLJCCKhAgW11GmOKiA4sC5EXfk3IPynG85Z2FdGJABiipPCnum9LEi3tZJzOuNLn JoIOQY3Bw4Ug== X-IronPort-AV: E=McAfee;i="6000,8403,9703"; a="140453772" X-IronPort-AV: E=Sophos;i="5.75,438,1589266800"; d="scan'208";a="140453772" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2020 08:05:32 -0700 IronPort-SDR: /0fvqCCw2zWAW2ZZYPKcBmmXuUDnbU6bQu2dYwx3IIx812nBJtqixeN9dACBkKBGfM3BpVyVBW ohbKSLQNIxGA== X-IronPort-AV: E=Sophos;i="5.75,438,1589266800"; d="scan'208";a="467495699" Received: from tlevis-mobl1.ger.corp.intel.com (HELO [10.251.167.151]) ([10.251.167.151]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2020 08:05:31 -0700 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20200805122231.23313-1-chris@chris-wilson.co.uk> <20200805122231.23313-4-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <9d313c82-2ee4-6edf-d734-79aac95a7697@linux.intel.com> Date: Wed, 5 Aug 2020 16:05:28 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200805122231.23313-4-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 03/37] drm/i915/gt: Free stale request on destroying the virtual engine 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 05/08/2020 13:21, Chris Wilson wrote: > Since preempt-to-busy, we may unsubmit a request while it is still on > the HW and completes asynchronously. That means it may be retired and in > the process destroy the virtual engine (as the user has closed their > context), but that engine may still be holding onto the unsubmitted > compelted request. Therefore we need to potentially cleanup the old > request on destroying the virtual engine. We also have to keep the > virtual_engine alive until after the sibling's execlists_dequeue() have > finished peeking into the virtual engines, for which we serialise with > RCU. > > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 417f6b0c6c61..cb04bc5474be 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -180,6 +180,7 @@ > #define EXECLISTS_REQUEST_SIZE 64 /* bytes */ > > struct virtual_engine { > + struct rcu_head rcu; > struct intel_engine_cs base; > struct intel_context context; > > @@ -5393,10 +5394,25 @@ static void virtual_context_destroy(struct kref *kref) > container_of(kref, typeof(*ve), context.ref); > unsigned int n; > > - GEM_BUG_ON(!list_empty(virtual_queue(ve))); > - GEM_BUG_ON(ve->request); > GEM_BUG_ON(ve->context.inflight); > > + if (unlikely(ve->request)) { > + struct i915_request *old; > + unsigned long flags; > + > + spin_lock_irqsave(&ve->base.active.lock, flags); > + > + old = fetch_and_zero(&ve->request); > + if (old) { > + GEM_BUG_ON(!i915_request_completed(old)); > + __i915_request_submit(old); > + i915_request_put(old); > + } > + > + spin_unlock_irqrestore(&ve->base.active.lock, flags); > + } > + GEM_BUG_ON(!list_empty(virtual_queue(ve))); > + > for (n = 0; n < ve->num_siblings; n++) { > struct intel_engine_cs *sibling = ve->siblings[n]; > struct rb_node *node = &ve->nodes[sibling->id].rb; > @@ -5422,7 +5438,7 @@ static void virtual_context_destroy(struct kref *kref) > intel_engine_free_request_pool(&ve->base); > > kfree(ve->bonds); > - kfree(ve); > + kfree_rcu(ve, rcu); > } > > static void virtual_engine_initial_hint(struct virtual_engine *ve) > If it would go without the previous patch I think it would simply mean a normal kfree here. In both cases it looks okay to me. Reviewed-by: Tvrtko Ursulin Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx