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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4CB6BC2BA83 for ; Fri, 14 Feb 2020 18:44:53 +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 1F7A720848 for ; Fri, 14 Feb 2020 18:44:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F7A720848 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk 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 95C4D6FB86; Fri, 14 Feb 2020 18:44:52 +0000 (UTC) Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id BABFA6FB86; Fri, 14 Feb 2020 18:44:50 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 20230044-1500050 for multiple; Fri, 14 Feb 2020 18:44:43 +0000 MIME-Version: 1.0 To: Antonio Argenziano , Dale B Stimson , igt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org From: Chris Wilson In-Reply-To: <9d522af3-470d-52f2-51e1-fef2ffdcfaa8@intel.com> References: <20200213192606.63025-1-dale.b.stimson@intel.com> <9d522af3-470d-52f2-51e1-fef2ffdcfaa8@intel.com> Message-ID: <158170587922.15393.4799274587942949539@skylake-alporthouse-com> User-Agent: alot/0.6 Date: Fri, 14 Feb 2020 18:44:39 +0000 Subject: Re: [Intel-gfx] [PATCH i-g-t] lib/i915/gem_engine_topology.c - intel_get_current_engine invalid result 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Quoting Antonio Argenziano (2020-02-14 18:43:01) > > > On 13/02/20 11:26, Dale B Stimson wrote: > > Function intel_get_current_engine() should return NULL (instead of > > engine 0) if there are no engines. > > > > Function intel_init_engine_list() should not store potential engine > > data in the output structure unless the engine is present. > > > > Function intel_init_engine_list() should arguably not filter the static > > engine list with gem_has_ring if fd == -1, so that subtests can still > > be individually invoked to show subtest FAIL instead of test notrun. > > > > Symptom: A device open failure in gem_ctx_isolation resulted in > > an endless __for_each_physical_engine "per-engine" loop with the > > purported last potential engine being processed every time. > > > > Diagnosis: device open (or debugfs open) failed, leaving fd == -1. > > Control skipped the rest of the initial igt_fixture block, after > > which an attempt was made to iterate through engines using macro > > __for_each_physical_engine. > > > > Macro __for_each_physical_engine called intel_init_engine_list() > > to initialize the loop control data. Because fd == -1, > > intel_init_engine_list() fell back to using __for_each_static_engine(). > > All of the engines in the static engine list are rejected due to > > gem_has_ring returning false (because of fd == -1), leaving 0 engines. > > That resulted in loop control data with engine_data.nengines == 0 > > and the data for the last engine considered stored at index 0. > > > > Still in macro __for_each_physical_engine, intel_get_current_engine() > > was called to get the engine to process. It should have returned NULL, > > but instead returned the engine entry at index 0, which > > had received information describing the last potential engine. > > This happened without end. > > > > Signed-off-by: Dale B Stimson > > --- > > lib/i915/gem_engine_topology.c | 29 ++++++++++++++++------------- > > 1 file changed, 16 insertions(+), 13 deletions(-) > > > > diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c > > index 9daa03df4..b8ed49bc9 100644 > > --- a/lib/i915/gem_engine_topology.c > > +++ b/lib/i915/gem_engine_topology.c > > @@ -156,10 +156,10 @@ static void query_engine_list(int fd, struct intel_engine_data *ed) > > struct intel_execution_engine2 * > > intel_get_current_engine(struct intel_engine_data *ed) > > { > > - if (!ed->n) > > - ed->current_engine = &ed->engines[0]; > > - else if (ed->n >= ed->nengines) > > + if (ed->n >= ed->nengines) > > ed->current_engine = NULL; > > + else if (!ed->n) > > + ed->current_engine = &ed->engines[0]; > > > > return ed->current_engine; > > } > > @@ -222,18 +222,21 @@ struct intel_engine_data intel_init_engine_list(int fd, uint32_t ctx_id) > > igt_debug("using pre-allocated engine list\n"); > > > > __for_each_static_engine(e2) { > > - struct intel_execution_engine2 *__e2 = > > - &engine_data.engines[engine_data.nengines]; > > - > > - strcpy(__e2->name, e2->name); > > - __e2->instance = e2->instance; > > - __e2->class = e2->class; > > - __e2->flags = e2->flags; > > - __e2->is_virtual = false; > > - > > if (igt_only_list_subtests() || > > - gem_has_ring(fd, e2->flags)) > > + (fd < 0) || > > Patch LGTM, Chris do you have any issues merging this before someone > implements some tests for the infrastructure? It seems like a really trivial one to write a test for. 3 minutes tops... Just do it. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx