From patchwork Fri Nov 17 13:29:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Kuoppala X-Patchwork-Id: 10062717 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A9B0A601D3 for ; Fri, 17 Nov 2017 13:29:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 99C882ACBA for ; Fri, 17 Nov 2017 13:29:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8EA912ACBC; Fri, 17 Nov 2017 13:29:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 27B002ACBA for ; Fri, 17 Nov 2017 13:29:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7F3416EA29; Fri, 17 Nov 2017 13:29:36 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id E0B8D6EA29 for ; Fri, 17 Nov 2017 13:29:35 +0000 (UTC) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Nov 2017 05:29:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,409,1505804400"; d="scan'208";a="6100021" Received: from gaia.fi.intel.com ([10.237.72.169]) by orsmga001.jf.intel.com with ESMTP; 17 Nov 2017 05:29:34 -0800 Received: by gaia.fi.intel.com (Postfix, from userid 1000) id 3B4ED5C0425; Fri, 17 Nov 2017 15:29:23 +0200 (EET) From: Mika Kuoppala To: Chris Wilson , intel-gfx@lists.freedesktop.org In-Reply-To: <20171114213023.11605-5-chris@chris-wilson.co.uk> References: <20171114213023.11605-1-chris@chris-wilson.co.uk> <20171114213023.11605-5-chris@chris-wilson.co.uk> Date: Fri, 17 Nov 2017 15:29:23 +0200 Message-ID: <87h8ttowy4.fsf@gaia.fi.intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [PATCH 5/8] drm/i915: Remove obsolete ringbuffer emission for gen8+ X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Chris Wilson writes: > Since removing the module parameter to force selection of ringbuffer > emission for gen8, the code is defunct. Remove it. > > To put the difference into perspective, a couple of microbenchmarks > (bdw i7-5557u, 20170324): > ring execlists > exec continuous nops on all rings: 1.491us 2.223us > exec sequential nops on each ring: 12.508us 53.682us > single nop + sync: 9.272us 30.291us > > vblank_mode=0 glxgears: ~11000fps ~9000fps > > Since the earlier submission, gen8 ringbuffer submission has fallen > further and further behind in features. So while ringbuffer may hold the > throughput crown, in terms of interactive latency, execlists is much > better. Alas, we have no convenient metrics for such, other than > demonstrating things we can do with execlists but can not using > legacy ringbuffer submission. > > We have made a few improvements to lowlevel execlists throughput, > and ringbuffer currently panics on boot! (bdw i7-5557u, 20171026): > > ring execlists > exec continuous nops on all rings: n/a 1.921us > exec sequential nops on each ring: n/a 44.621us > single nop + sync: n/a 21.953us > > vblank_mode=0 glxgears: n/a ~18500fps > > References: https://bugs.freedesktop.org/show_bug.cgi?id=87725 > Signed-off-by: Chris Wilson > Once-upon-a-time-Reviewed-by: Joonas Lahtinen lgtm but found one thing more we can throw out: Reviewed-by: Mika Kuoppala diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 45835d83dfbf..873439abc415 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -37,8 +37,6 @@ * Resource Streamer, is 66944 bytes, which rounds to 17 pages. */ #define HSW_CXT_TOTAL_SIZE (17 * PAGE_SIZE) -/* Same as Haswell, but 72064 bytes now. */ -#define GEN8_CXT_TOTAL_SIZE (18 * PAGE_SIZE) #define GEN8_LR_CONTEXT_RENDER_SIZE (20 * PAGE_SIZE) #define GEN9_LR_CONTEXT_RENDER_SIZE (22 * PAGE_SIZE) @@ -164,9 +162,7 @@ __intel_engine_context_size(struct drm_i915_private *dev_priv, u8 class) case 9: return GEN9_LR_CONTEXT_RENDER_SIZE; case 8: - return i915_modparams.enable_execlists ? - GEN8_LR_CONTEXT_RENDER_SIZE : - GEN8_CXT_TOTAL_SIZE; + return GEN8_LR_CONTEXT_RENDER_SIZE; case 7: With that included,