From patchwork Thu May 6 17:30:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12242827 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BC77AC433B4 for ; Thu, 6 May 2021 17:13:20 +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 69D3960FF3 for ; Thu, 6 May 2021 17:13:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 69D3960FF3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 787176ECDD; Thu, 6 May 2021 17:13:08 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1FE776ECC0; Thu, 6 May 2021 17:13:06 +0000 (UTC) IronPort-SDR: ATD1KuMwL9Mebz0fGuPtxc7g0MSnsBQjrkrWwEQxr2Gv/Ghd1HKobkUHY7DI2bbbrdTPi792fQ bszcD4hUIZbA== X-IronPort-AV: E=McAfee;i="6200,9189,9976"; a="198613103" X-IronPort-AV: E=Sophos;i="5.82,278,1613462400"; d="scan'208";a="198613103" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 May 2021 10:13:04 -0700 IronPort-SDR: 9rfXXkPDbQq7RU0fixbnkqVwzWDyAIfQFPb7JVHKksFrdIL3Fpx8L4DSerMGZFhhcYATqzItYo Tdg/p5+a1EOg== X-IronPort-AV: E=Sophos;i="5.82,278,1613462400"; d="scan'208";a="622533950" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 May 2021 10:13:03 -0700 From: Matthew Brost To: , Subject: [RFC PATCH 1/5] drm/doc/rfc: i915 GuC submission / DRM scheduler integration plan Date: Thu, 6 May 2021 10:30:45 -0700 Message-Id: <20210506173049.72503-2-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210506173049.72503-1-matthew.brost@intel.com> References: <20210506173049.72503-1-matthew.brost@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: matthew.brost@intel.com, tony.ye@intel.com, tvrtko.ursulin@intel.com, daniele.ceraolospurio@intel.com, carl.zhang@intel.com, jason.ekstrand@intel.com, jon.bloomfield@intel.com, daniel.vetter@intel.com, john.c.harrison@intel.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add entry for i915 GuC submission / DRM scheduler integration plan. Follow up patch with details of new parallel submission uAPI to come. Cc: Jon Bloomfield Cc: Jason Ekstrand Cc: Dave Airlie Cc: Daniel Vetter Cc: Jason Ekstrand Cc: dri-devel@lists.freedesktop.org Signed-off-by: Matthew Brost --- Documentation/gpu/rfc/i915_scheduler.rst | 70 ++++++++++++++++++++++++ Documentation/gpu/rfc/index.rst | 4 ++ 2 files changed, 74 insertions(+) create mode 100644 Documentation/gpu/rfc/i915_scheduler.rst diff --git a/Documentation/gpu/rfc/i915_scheduler.rst b/Documentation/gpu/rfc/i915_scheduler.rst new file mode 100644 index 000000000000..fa6780a11c86 --- /dev/null +++ b/Documentation/gpu/rfc/i915_scheduler.rst @@ -0,0 +1,70 @@ +========================================= +I915 GuC Submission/DRM Scheduler Section +========================================= + +Upstream plan +============= +For upstream the overall plan for landing GuC submission and integrating the +i915 with the DRM scheduler is: + +* Merge basic GuC submission + * Basic submission support for all gen11+ platforms + * Not enabled by default on any current platforms but can be enabled via + modparam enable_guc + * Lots of rework will need to be done to integrate with DRM scheduler so + no need to nit pick everything in the code, it just should be + functional and not regress execlists + * Update IGTs / selftests as needed to work with GuC submission + * Enable CI on supported platforms for a baseline + * Rework / get CI heathly for GuC submission in place as needed +* Merge new parallel submission uAPI + * Bonding uAPI completely incompatible with GuC submission + * New uAPI adds I915_CONTEXT_ENGINES_EXT_PARALLEL context setup step + which configures contexts N wide + * After I915_CONTEXT_ENGINES_EXT_PARALLEL a user can submit N batches to + a context in a single execbuf IOCTL and the batches run on the GPU in + paralllel + * Initially only for GuC submission but execlists can be supported if + needed +* Convert the i915 to use the DRM scheduler + * GuC submission backend fully integrated with DRM scheduler + * All request queues removed from backend (e.g. all backpressure + handled in DRM scheduler) + * Resets / cancels hook in DRM scheduler + * Watchdog hooks into DRM scheduler + * Lots of complexity of the GuC backend can be pulled out once + integrated with DRM scheduler (e.g. state machine gets + simplier, locking gets simplier, etc...) + * Execlist backend will do the minimum required to hook in the DRM + scheduler so it can live next to the fully integrated GuC backend + * Legacy interface + * Features like timeslicing / preemption / virtual engines would + be difficult to integrate with the DRM scheduler and these + features are not required for GuC submission as the GuC does + these things for us + * ROI low on fully integrating into DRM scheduler + * Fully integrating would add lots of complexity to DRM + scheduler + * Port i915 priority inheritance / boosting feature in DRM scheduler + * Remove in-order completion assumptions from DRM scheduler + * Pull out i915 priority levels and use DRM priority levels + * Optimize DRM scheduler as needed + +New uAPI for basic GuC submission +================================= +No major changes are required to the uAPI for basic GuC submission. The only +change is a new scheduler attribute: I915_SCHEDULER_CAP_STATIC_PRIORITY_MAP. +This attribute indicates the 2k i915 user priority levels are statically mapped +into 3 levels as follows: + +* -1k to -1 Low priority +* 0 Medium priority +* 1 to 1k High priority + +This is needed because the GuC only has 4 priority bands. The highest priority +band is reserved with the kernel. This aligns with the DRM scheduler priority +levels too. + +New parallel submission uAPI +============================ +Details to come in a following patch. diff --git a/Documentation/gpu/rfc/index.rst b/Documentation/gpu/rfc/index.rst index a8621f7dab8b..018a8bf317a6 100644 --- a/Documentation/gpu/rfc/index.rst +++ b/Documentation/gpu/rfc/index.rst @@ -15,3 +15,7 @@ host such documentation: * Once the code has landed move all the documentation to the right places in the main core, helper or driver sections. + +.. toctree:: + + i915_scheduler.rst