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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,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 86D08C2D0E4 for ; Tue, 24 Nov 2020 17:13:09 +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 1E325206E5 for ; Tue, 24 Nov 2020 17:13:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E325206E5 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 61BFA6E4C5; Tue, 24 Nov 2020 17:13:08 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 48F0B6E4C5 for ; Tue, 24 Nov 2020 17:13:07 +0000 (UTC) IronPort-SDR: NivaqmbGES643rO7tgb7H0m9jTK8BwyLRp1u2RdGPO7zInjDknHWZaxifx07TrPEUtbfdp/B+9 2Q9jti/MaxkA== X-IronPort-AV: E=McAfee;i="6000,8403,9815"; a="169419721" X-IronPort-AV: E=Sophos;i="5.78,366,1599548400"; d="scan'208";a="169419721" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Nov 2020 09:13:06 -0800 IronPort-SDR: ff+5NRp5iYsWZa0SfZLkaj4R5mYInNwwiaVDspIKQ42s5rzXbm+rtzuErW03bB3YxU2L6rsLH2 3E1XRQAkGlnw== X-IronPort-AV: E=Sophos;i="5.78,366,1599548400"; d="scan'208";a="546909528" Received: from ipilchin-mobl1.ger.corp.intel.com (HELO [10.254.159.60]) ([10.254.159.60]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Nov 2020 09:13:05 -0800 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20201124114219.29020-1-chris@chris-wilson.co.uk> <20201124114219.29020-6-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: Date: Tue, 24 Nov 2020 17:13:02 +0000 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: <20201124114219.29020-6-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 06/16] drm/i915/gt: Decouple completed requests on unwind 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 24/11/2020 11:42, Chris Wilson wrote: > Since the introduction of preempt-to-busy, requests can complete in the > background, even while they are not on the engine->active.requests list. > As such, the engine->active.request list itself is not in strict > retirement order, and we have to scan the entire list while unwinding to > not miss any. However, if the request is completed we currently leave it > on the list [until retirement], but we could just as simply remove it > and stop treating it as active. We would only have to then traverse it > once while unwinding in quick succession. > > Signed-off-by: Chris Wilson > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 6 ++++-- > drivers/gpu/drm/i915/i915_request.c | 3 ++- > 2 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 30aa59fb7271..cf11cbac241b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -1116,8 +1116,10 @@ __unwind_incomplete_requests(struct intel_engine_cs *engine) > list_for_each_entry_safe_reverse(rq, rn, > &engine->active.requests, > sched.link) { > - if (i915_request_completed(rq)) > - continue; /* XXX */ > + if (i915_request_completed(rq)) { > + list_del_init(&rq->sched.link); > + continue; > + } > > __i915_request_unsubmit(rq); > > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c > index 8d7d29c9e375..a9db1376b996 100644 > --- a/drivers/gpu/drm/i915/i915_request.c > +++ b/drivers/gpu/drm/i915/i915_request.c > @@ -321,7 +321,8 @@ bool i915_request_retire(struct i915_request *rq) > * after removing the breadcrumb and signaling it, so that we do not > * inadvertently attach the breadcrumb to a completed request. > */ > - remove_from_engine(rq); > + if (!list_empty(&rq->sched.link)) > + remove_from_engine(rq); The list_empty check is unlocked so is list_del_init in remove_from_engine safe on potentially already unlinked request or it needs to re-check under the lock? Regards, Tvrtko > GEM_BUG_ON(!llist_empty(&rq->execute_cb)); > > __list_del_entry(&rq->link); /* poison neither prev/next (RCU walks) */ > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx