From patchwork Tue Jul 6 22:20:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12361199 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=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 38C81C07E96 for ; Tue, 6 Jul 2021 22:02:43 +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 F34356140F for ; Tue, 6 Jul 2021 22:02:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F34356140F 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 20AE46E7D0; Tue, 6 Jul 2021 22:02:29 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0C2476E5C5; Tue, 6 Jul 2021 22:02:23 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="206190487" X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="206190487" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 15:02:19 -0700 X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="410367912" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 15:02:18 -0700 From: Matthew Brost To: , Subject: [PATCH 3/7] drm/i915/guc: Increase size of CTB buffers Date: Tue, 6 Jul 2021 15:20:06 -0700 Message-Id: <20210706222010.101522-4-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210706222010.101522-1-matthew.brost@intel.com> References: <20210706222010.101522-1-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: john.c.harrison@intel.com, Michal.Wajdeczko@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 Reviewed-by: Michal Wajdeczko --- 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 80db59b45c45..43e03aa2dde8 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -58,11 +58,16 @@ 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 + * 2 dwords 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) struct ct_request { struct list_head link; @@ -643,7 +648,7 @@ 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];