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=-14.4 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 ACB54C433DB for ; Tue, 2 Feb 2021 16:52:28 +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 3DC5164E3F for ; Tue, 2 Feb 2021 16:52:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3DC5164E3F 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 9C9DF6E1C0; Tue, 2 Feb 2021 16:52:27 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id DEC0B6E1C0 for ; Tue, 2 Feb 2021 16:52:26 +0000 (UTC) IronPort-SDR: Dk1V+L5gnImPcpl6pUQ50hxBRpoaCxPfCqDfidPgoWBKERXSTtyxvHGKeumAiJnqFEoOm+qbVf PN4coQx9TwGQ== X-IronPort-AV: E=McAfee;i="6000,8403,9883"; a="160054191" X-IronPort-AV: E=Sophos;i="5.79,395,1602572400"; d="scan'208";a="160054191" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2021 08:52:24 -0800 IronPort-SDR: LxM9bWH8QaBP/kU1HTO4Izp9BXHJ8+GTKicocIkQbzj0v6HCQuQ8ytbLzKACtpE7Llt97JZ7qF VfUdHQrK5QNA== X-IronPort-AV: E=Sophos;i="5.79,395,1602572400"; d="scan'208";a="433001875" Received: from irisshal-mobl1.ger.corp.intel.com (HELO [10.214.210.18]) ([10.214.210.18]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2021 08:52:22 -0800 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20210202151445.20002-1-chris@chris-wilson.co.uk> <20210202151445.20002-8-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <2097da50-efe4-1b23-67b5-9a43a70198c9@linux.intel.com> Date: Tue, 2 Feb 2021 16:52:18 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20210202151445.20002-8-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [CI 08/14] drm/i915/selftests: Force a rewind if at first we don't succeed 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 02/02/2021 15:14, Chris Wilson wrote: > live_timeslice_rewind assumes a particular traversal and reordering > after the first timeslice yield. However, the outcome can be either > (A1, A2, B1) or (A1, B2, A2) depending on the path taken through the > dependency graph. So if we do not get the outcome we need at first, give > it a priority kick to force a rewind. > > Signed-off-by: Chris Wilson > --- > drivers/gpu/drm/i915/gt/selftest_execlists.c | 21 +++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c > index 951e2bf867e1..68e1398704a4 100644 > --- a/drivers/gpu/drm/i915/gt/selftest_execlists.c > +++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c > @@ -1107,6 +1107,7 @@ static int live_timeslice_rewind(void *arg) > struct i915_request *rq[3] = {}; > struct intel_context *ce; > unsigned long timeslice; > + unsigned long timeout; > int i, err = 0; > u32 *slot; > > @@ -1173,11 +1174,29 @@ static int live_timeslice_rewind(void *arg) > > /* ELSP[] = { { A:rq1, A:rq2 }, { B:rq1 } } */ > ENGINE_TRACE(engine, "forcing tasklet for rewind\n"); > - while (i915_request_is_active(rq[A2])) { /* semaphore yield! */ > + i = 0; > + timeout = jiffies + HZ; > + while (i915_request_is_active(rq[A2]) && > + time_before(jiffies, timeout)) { /* semaphore yield! */ > /* Wait for the timeslice to kick in */ > del_timer(&engine->execlists.timer); > tasklet_hi_schedule(&engine->execlists.tasklet); > intel_engine_flush_submission(engine); > + > + /* > + * Unfortunately this assumes that during the > + * search of the wait tree it sees the requests > + * in a particular order. That order is not > + * strictly determined and it may pick either > + * A2 or B1 to immediately follow A1. > + * > + * Break the tie with a set-priority. This defeats > + * the goal of trying to cause a rewind with a > + * timeslice, but alas, a rewind is better than > + * none. > + */ > + if (i++) > + i915_request_set_priority(rq[B1], 1); > } > /* -> ELSP[] = { { A:rq1 }, { B:rq1 } } */ > GEM_BUG_ON(!i915_request_is_active(rq[A1])); > Didn't fully get the intricacies of the test, but, how about not messing with priorities but just kicking it for longer until it eventually re-orders to the desired sequence? Surely if it keeps insisting of the same order which is making no progress there is a flaw in timeslicing anyway? Or if it fails skip the test. Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx