From patchwork Mon Feb 27 21:08:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Shyti X-Patchwork-Id: 13154189 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id F2243C64ED6 for ; Mon, 27 Feb 2023 21:09:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6DB6510E43B; Mon, 27 Feb 2023 21:08:51 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 85D3B10E40F; Mon, 27 Feb 2023 21:08:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677532129; x=1709068129; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=RQP1V7phNoi9kxLvQc7zfV7/kBtqWl1sfDhMmrTbiNM=; b=VWZV40S4zPRzmQKcvdVYGmVu9e6ewTUZS2eB+RXFIjG6cMX7/llCkhkm 7Ec1KRWad1qJM4Kpe1ljsWpqEhhuJHjTzPP+i1OzWFxpU6/mLOhtrZVau CH8IFZfYHpTjn07CaUudHmbt8uTwMV9cKdrq5eSobaFb5dNg/d6bV6/8j 3mRbnV5e0GSovnDAGjwG8Qd6QG37BNUAusjzxAWZzOQnc7PW74fIJ7da2 OyojLyy2aQzFMBrXog47TUHtRjgPdUEBpynrGk1ogIflB9ARL4Ln7/V5J kaNzpbtuHnS4YgXcUXih0ngls3fm2Yxt38zKr5r9TK4caKrBLpqO0GVcL A==; X-IronPort-AV: E=McAfee;i="6500,9779,10634"; a="317767925" X-IronPort-AV: E=Sophos;i="5.98,220,1673942400"; d="scan'208";a="317767925" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Feb 2023 13:08:49 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10634"; a="623761625" X-IronPort-AV: E=Sophos;i="5.98,220,1673942400"; d="scan'208";a="623761625" Received: from jrissane-mobl2.ger.corp.intel.com (HELO intel.com) ([10.249.41.42]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Feb 2023 13:08:34 -0800 From: Andi Shyti To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, stable@vger.kernel.org Subject: [PATCH v2 1/2] drm/i915: Throttle for ringspace prior to taking the timeline mutex Date: Mon, 27 Feb 2023 22:08:17 +0100 Message-Id: <20230227210818.1731172-2-andi.shyti@linux.intel.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230227210818.1731172-1-andi.shyti@linux.intel.com> References: <20230227210818.1731172-1-andi.shyti@linux.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: Andi Shyti , Chris Wilson , Matthew Auld , Andi Shyti , Chris Wilson , Maciej Patelczyk Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Chris Wilson Before taking exclusive ownership of the ring for emitting the request, wait for space in the ring to become available. This allows others to take the timeline->mutex to make forward progresses while userspace is blocked. In particular, this allows regular clients to issue requests on the kernel context, potentially filling the ring, but allow the higher priority heartbeats and pulses to still be submitted without being blocked by the less critical work. Fixes: cf586021642d80 ("drm/i915/gt: Pipelined page migration") Signed-off-by: Chris Wilson Cc: Maciej Patelczyk Cc: stable@vger.kernel.org Signed-off-by: Andi Shyti --- Hi, I'm not sure I need to add the Fixes tag here as this is more preparatory for the next patch. Together, though, patch 1 and 2 make the fix with proper locking mechanism. Andi drivers/gpu/drm/i915/gt/intel_context.c | 41 +++++++++++++++++++++++++ drivers/gpu/drm/i915/gt/intel_context.h | 2 ++ drivers/gpu/drm/i915/i915_request.c | 3 ++ 3 files changed, 46 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index 2aa63ec521b89..59cd612a23561 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -626,6 +626,47 @@ bool intel_context_revoke(struct intel_context *ce) return ret; } +int intel_context_throttle(const struct intel_context *ce) +{ + const struct intel_ring *ring = ce->ring; + const struct intel_timeline *tl = ce->timeline; + struct i915_request *rq; + int err = 0; + + if (READ_ONCE(ring->space) >= SZ_1K) + return 0; + + rcu_read_lock(); + list_for_each_entry_reverse(rq, &tl->requests, link) { + if (__i915_request_is_complete(rq)) + break; + + if (rq->ring != ring) + continue; + + /* Wait until there will be enough space following that rq */ + if (__intel_ring_space(rq->postfix, + ring->emit, + ring->size) < ring->size / 2) { + if (i915_request_get_rcu(rq)) { + rcu_read_unlock(); + + if (i915_request_wait(rq, + I915_WAIT_INTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT) < 0) + err = -EINTR; + + rcu_read_lock(); + i915_request_put(rq); + } + break; + } + } + rcu_read_unlock(); + + return err; +} + #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) #include "selftest_context.c" #endif diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index 0a8d553da3f43..f919a66cebf5b 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -226,6 +226,8 @@ static inline void intel_context_exit(struct intel_context *ce) ce->ops->exit(ce); } +int intel_context_throttle(const struct intel_context *ce); + static inline struct intel_context *intel_context_get(struct intel_context *ce) { kref_get(&ce->ref); diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 7503dcb9043bb..a1741c4a8cffd 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1035,6 +1035,9 @@ i915_request_create(struct intel_context *ce) struct i915_request *rq; struct intel_timeline *tl; + if (intel_context_throttle(ce)) + return ERR_PTR(-EINTR); + tl = intel_context_timeline_lock(ce); if (IS_ERR(tl)) return ERR_CAST(tl);