From patchwork Thu May 6 19:13:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12243063 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,URIBL_BLOCKED,USER_AGENT_GIT 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 12171C43462 for ; Thu, 6 May 2021 18:58:59 +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 BF84561001 for ; Thu, 6 May 2021 18:58:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF84561001 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 8E1AB6EDCA; Thu, 6 May 2021 18:57:29 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2C8826ED06; Thu, 6 May 2021 18:57:13 +0000 (UTC) IronPort-SDR: VE2WcL2acwM0MwJqLdnecrJpzcUjt11pkAPbXrn6hvAD+y5SOmJjsYCYaelZeR9Rz+LFxQwfvq 73B9x4uEsGeQ== X-IronPort-AV: E=McAfee;i="6200,9189,9976"; a="196531007" X-IronPort-AV: E=Sophos;i="5.82,278,1613462400"; d="scan'208";a="196531007" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 May 2021 11:57:12 -0700 IronPort-SDR: jNfQ+lix+OmSqmQXTZFvHTIb+BstXea6NbwCUCQ4VZxgZp0ctz9BsndFReEaD6KR9G/tHNxDVO 9N6vea34es2w== X-IronPort-AV: E=Sophos;i="5.82,278,1613462400"; d="scan'208";a="469583478" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 May 2021 11:57:10 -0700 From: Matthew Brost To: , Subject: [RFC PATCH 39/97] drm/i915/guc: Increase size of CTB buffers Date: Thu, 6 May 2021 12:13:53 -0700 Message-Id: <20210506191451.77768-40-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210506191451.77768-1-matthew.brost@intel.com> References: <20210506191451.77768-1-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, tvrtko.ursulin@intel.com, daniele.ceraolospurio@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" With the introduction of non-blocking CTBs more than one CTB can be in flight at a time. Increasing the size of the CTBs should reduce how often software hits the case where no space is available in the CTB buffer. Cc: John Harrison Signed-off-by: Matthew Brost --- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index 77dfbc94dcc3..d6895d29ed2d 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -63,11 +63,16 @@ static inline struct drm_device *ct_to_drm(struct intel_guc_ct *ct) * +--------+-----------------------------------------------+------+ * * Size of each `CT Buffer`_ must be multiple of 4K. - * As we don't expect too many messages, for now use minimum sizes. + * We don't expect too many messages in flight at any time, unless we are + * using the GuC submission. In that case each request requires a minimum + * 16 bytes which gives us a maximum 256 queue'd requests. Hopefully this + * enough space to avoid backpressure on the driver. We increase the size + * of the receive buffer (relative to the send) to ensure a G2H response + * CTB has a landing spot. */ #define CTB_DESC_SIZE ALIGN(sizeof(struct guc_ct_buffer_desc), SZ_2K) #define CTB_H2G_BUFFER_SIZE (SZ_4K) -#define CTB_G2H_BUFFER_SIZE (SZ_4K) +#define CTB_G2H_BUFFER_SIZE (4 * CTB_H2G_BUFFER_SIZE) #define MAX_US_STALL_CTB 1000000 @@ -753,7 +758,7 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg) /* beware of buffer wrap case */ if (unlikely(available < 0)) available += size; - CT_DEBUG(ct, "available %d (%u:%u)\n", available, head, tail); + CT_DEBUG(ct, "available %d (%u:%u:%u)\n", available, head, tail, size); GEM_BUG_ON(available < 0); header = cmds[head];