Attachment 120645 Details for Bug 93467 – Move execlists to bottom-half

[patch] Move execlists to bottom-half

0001-drm-i915-Move-execlists-interrupt-based-submission-t.patch (text/plain), 12.57 KB, created by Chris Wilson on 2015-12-21 21:48:48 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Chris Wilson

Created: 2015-12-21 21:48:48 UTC

Size: 12.57 KB

patch

obsolete

>From fdcc983e084d4e4c3810db84815474a419e918e7 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Mon, 21 Dec 2015 16:55:43 +0000
>Subject: [PATCH] drm/i915: Move execlists interrupt based submission to a
> bottom-half
>
>[  196.988204] clocksource: timekeeping watchdog: Marking clocksource 'tsc' as unstable because the skew is too large:
>[  196.988512] clocksource:                       'refined-jiffies' wd_now: ffff9b48 wd_last: ffff9acb mask: ffffffff
>[  196.988559] clocksource:                       'tsc' cs_now: 4fcfa84354 cs_last: 4f95425e98 mask: ffffffffffffffff
>[  196.992115] clocksource: Switched to clocksource refined-jiffies
>
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> drivers/gpu/drm/i915/i915_debugfs.c     |   5 +-
> drivers/gpu/drm/i915/i915_gem.c         |  13 +--
> drivers/gpu/drm/i915/i915_irq.c         |   2 +-
> drivers/gpu/drm/i915/intel_lrc.c        | 147 +++++++++++++++++++-------------
> drivers/gpu/drm/i915/intel_lrc.h        |   1 -
> drivers/gpu/drm/i915/intel_ringbuffer.h |   1 +
> 6 files changed, 94 insertions(+), 75 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>index 137e6743ebbb..ac2c8dc0adcc 100644
>--- a/drivers/gpu/drm/i915/i915_debugfs.c
>+++ b/drivers/gpu/drm/i915/i915_debugfs.c
>@@ -2076,7 +2076,6 @@ static int i915_execlists(struct seq_file *m, void *data)
> 	for_each_ring(ring, dev_priv, ring_id) {
> 		struct drm_i915_gem_request *head_req = NULL;
> 		int count = 0;
>-		unsigned long flags;
> 
> 		seq_printf(m, "%s\n", ring->name);
> 
>@@ -2103,12 +2102,12 @@ static int i915_execlists(struct seq_file *m, void *data)
> 				   i, status, ctx_id);
> 		}
> 
>-		spin_lock_irqsave(&ring->execlist_lock, flags);
>+		spin_lock(&ring->execlist_lock);
> 		list_for_each(cursor, &ring->execlist_queue)
> 			count++;
> 		head_req = list_first_entry_or_null(&ring->execlist_queue,
> 				struct drm_i915_gem_request, execlist_link);
>-		spin_unlock_irqrestore(&ring->execlist_lock, flags);
>+		spin_unlock(&ring->execlist_lock);
> 
> 		seq_printf(m, "\t%d requests in queue\n", count);
> 		if (head_req) {
>diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>index 730a6d2f5163..d1ce86dbe5be 100644
>--- a/drivers/gpu/drm/i915/i915_gem.c
>+++ b/drivers/gpu/drm/i915/i915_gem.c
>@@ -2182,13 +2182,13 @@ static void i915_gem_reset_ring_cleanup(struct intel_engine_cs *engine)
> 	 */
> 
> 	if (i915.enable_execlists) {
>-		spin_lock_irq(&engine->execlist_lock);
>+		spin_lock(&engine->execlist_lock);
> 
> 		/* list_splice_tail_init checks for empty lists */
> 		list_splice_tail_init(&engine->execlist_queue,
> 				      &engine->execlist_retired_req_list);
> 
>-		spin_unlock_irq(&engine->execlist_lock);
>+		spin_unlock(&engine->execlist_lock);
> 		intel_execlists_retire_requests(engine);
> 	}
> 
>@@ -2282,15 +2282,8 @@ i915_gem_retire_requests(struct drm_device *dev)
> 	for_each_ring(ring, dev_priv, i) {
> 		i915_gem_retire_requests_ring(ring);
> 		idle &= list_empty(&ring->request_list);
>-		if (i915.enable_execlists) {
>-			unsigned long flags;
>-
>-			spin_lock_irqsave(&ring->execlist_lock, flags);
>-			idle &= list_empty(&ring->execlist_queue);
>-			spin_unlock_irqrestore(&ring->execlist_lock, flags);
>-
>+		if (i915.enable_execlists)
> 			intel_execlists_retire_requests(ring);
>-		}
> 	}
> 
> 	if (idle)
>diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>index 43f333851561..724478f005f9 100644
>--- a/drivers/gpu/drm/i915/i915_irq.c
>+++ b/drivers/gpu/drm/i915/i915_irq.c
>@@ -1314,7 +1314,7 @@ gen8_cs_irq_handler(struct intel_engine_cs *ring, u32 iir, int test_shift)
> 	if (iir & (GT_RENDER_USER_INTERRUPT << test_shift))
> 		notify_ring(ring);
> 	if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << test_shift))
>-		intel_lrc_irq_handler(ring);
>+		wake_up_process(ring->execlists_submit);
> }
> 
> static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
>diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
>index 690374379b7e..021afa6bbf0d 100644
>--- a/drivers/gpu/drm/i915/intel_lrc.c
>+++ b/drivers/gpu/drm/i915/intel_lrc.c
>@@ -132,6 +132,8 @@
>  *
>  */
> 
>+#include <linux/kthread.h>
>+
> #include <drm/drmP.h>
> #include <drm/i915_drm.h>
> #include "i915_drv.h"
>@@ -341,7 +343,7 @@ static void execlists_elsp_write(struct drm_i915_gem_request *rq0,
> 	rq0->elsp_submitted++;
> 
> 	/* You must always write both descriptors in the order below. */
>-	spin_lock(&dev_priv->uncore.lock);
>+	spin_lock_irq(&dev_priv->uncore.lock);
> 	intel_uncore_forcewake_get__locked(dev_priv, FORCEWAKE_ALL);
> 	I915_WRITE_FW(RING_ELSP(engine), upper_32_bits(desc[1]));
> 	I915_WRITE_FW(RING_ELSP(engine), lower_32_bits(desc[1]));
>@@ -353,7 +355,7 @@ static void execlists_elsp_write(struct drm_i915_gem_request *rq0,
> 	/* ELSP is a wo register, use another nearby reg for posting */
> 	POSTING_READ_FW(RING_EXECLIST_STATUS_LO(engine));
> 	intel_uncore_forcewake_put__locked(dev_priv, FORCEWAKE_ALL);
>-	spin_unlock(&dev_priv->uncore.lock);
>+	spin_unlock_irq(&dev_priv->uncore.lock);
> }
> 
> static int execlists_update_context(struct drm_i915_gem_request *rq)
>@@ -492,73 +494,84 @@ static bool execlists_check_remove_request(struct intel_engine_cs *ring,
> 	return false;
> }
> 
>-/**
>- * intel_lrc_irq_handler() - handle Context Switch interrupts
>- * @ring: Engine Command Streamer to handle.
>- *
>- * Check the unread Context Status Buffers and manage the submission of new
>- * contexts to the ELSP accordingly.
>- */
>-void intel_lrc_irq_handler(struct intel_engine_cs *ring)
>+static void set_rtpriority(void)
> {
>-	struct drm_i915_private *dev_priv = ring->dev->dev_private;
>-	u32 status_pointer;
>-	u8 read_pointer;
>-	u8 write_pointer;
>-	u32 status = 0;
>-	u32 status_id;
>-	u32 submit_contexts = 0;
>+	 struct sched_param param = { .sched_priority = 1 };
>+	 sched_setscheduler_nocheck(current, SCHED_FIFO, &param);
>+}
>+
>+static int intel_execlists_submit(void *arg)
>+{
>+	struct intel_engine_cs *ring = arg;
>+	struct drm_i915_private *dev_priv = ring->i915;
> 
>-	status_pointer = I915_READ(RING_CONTEXT_STATUS_PTR(ring));
>+	set_rtpriority();
> 
>-	read_pointer = ring->next_context_status_buffer;
>-	write_pointer = status_pointer & GEN8_CSB_PTR_MASK;
>-	if (read_pointer > write_pointer)
>-		write_pointer += GEN8_CSB_ENTRIES;
>+	do {
>+		u32 status;
>+		u32 status_id;
>+		u32 submit_contexts;
>+		u8 head, tail;
> 
>-	spin_lock(&ring->execlist_lock);
>+		set_current_state(TASK_INTERRUPTIBLE);
>+		head = ring->next_context_status_buffer;
>+		tail = I915_READ(RING_CONTEXT_STATUS_PTR(ring)) & GEN8_CSB_PTR_MASK;
> 
>-	while (read_pointer < write_pointer) {
>-		read_pointer++;
>-		status = I915_READ(RING_CONTEXT_STATUS_BUF_LO(ring, read_pointer % GEN8_CSB_ENTRIES));
>-		status_id = I915_READ(RING_CONTEXT_STATUS_BUF_HI(ring, read_pointer % GEN8_CSB_ENTRIES));
>+		if (head == tail) {
>+			if (kthread_should_stop())
>+				return 0;
> 
>-		if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
>+			schedule();
> 			continue;
>-
>-		if (status & GEN8_CTX_STATUS_PREEMPTED) {
>-			if (status & GEN8_CTX_STATUS_LITE_RESTORE) {
>-				if (execlists_check_remove_request(ring, status_id))
>-					WARN(1, "Lite Restored request removed from queue\n");
>-			} else
>-				WARN(1, "Preemption without Lite Restore\n");
> 		}
> 
>-		 if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) ||
>-		     (status & GEN8_CTX_STATUS_ELEMENT_SWITCH)) {
>-			if (execlists_check_remove_request(ring, status_id))
>-				submit_contexts++;
>+		if (head > tail)
>+			tail += GEN8_CSB_ENTRIES;
>+
>+		status = 0;
>+		submit_contexts = 0;
>+
>+		spin_lock(&ring->execlist_lock);
>+
>+		while (head++ < tail) {
>+			status = I915_READ(RING_CONTEXT_STATUS_BUF_LO(ring, head % GEN8_CSB_ENTRIES));
>+			status_id = I915_READ(RING_CONTEXT_STATUS_BUF_HI(ring, head % GEN8_CSB_ENTRIES));
>+
>+			if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
>+				continue;
>+
>+			if (status & GEN8_CTX_STATUS_PREEMPTED) {
>+				if (status & GEN8_CTX_STATUS_LITE_RESTORE) {
>+					if (execlists_check_remove_request(ring, status_id))
>+						WARN(1, "Lite Restored request removed from queue\n");
>+				} else
>+					WARN(1, "Preemption without Lite Restore\n");
>+			}
>+
>+			if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) ||
>+					(status & GEN8_CTX_STATUS_ELEMENT_SWITCH)) {
>+				if (execlists_check_remove_request(ring, status_id))
>+					submit_contexts++;
>+			}
> 		}
>-	}
> 
>-	if (disable_lite_restore_wa(ring)) {
>-		/* Prevent a ctx to preempt itself */
>-		if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) &&
>-		    (submit_contexts != 0))
>+		if (disable_lite_restore_wa(ring)) {
>+			/* Prevent a ctx to preempt itself */
>+			if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) &&
>+					(submit_contexts != 0))
>+				execlists_context_unqueue(ring);
>+		} else if (submit_contexts != 0) {
> 			execlists_context_unqueue(ring);
>-	} else if (submit_contexts != 0) {
>-		execlists_context_unqueue(ring);
>-	}
>-
>-	spin_unlock(&ring->execlist_lock);
>+		}
> 
>-	WARN(submit_contexts > 2, "More than two context complete events?\n");
>-	ring->next_context_status_buffer = write_pointer % GEN8_CSB_ENTRIES;
>+		spin_unlock(&ring->execlist_lock);
> 
>-	I915_WRITE(RING_CONTEXT_STATUS_PTR(ring),
>-		   _MASKED_FIELD(GEN8_CSB_PTR_MASK << 8,
>-				 ((u32)ring->next_context_status_buffer &
>-				  GEN8_CSB_PTR_MASK) << 8));
>+		WARN(submit_contexts > 2, "More than two context complete events?\n");
>+		ring->next_context_status_buffer = tail % GEN8_CSB_ENTRIES;
>+		I915_WRITE(RING_CONTEXT_STATUS_PTR(ring),
>+			   _MASKED_FIELD(GEN8_CSB_PTR_MASK << 8,
>+					 ring->next_context_status_buffer<<8));
>+	} while (1);
> }
> 
> static int execlists_context_queue(struct drm_i915_gem_request *request)
>@@ -569,7 +582,7 @@ static int execlists_context_queue(struct drm_i915_gem_request *request)
> 
> 	i915_gem_request_reference(request);
> 
>-	spin_lock_irq(&engine->execlist_lock);
>+	spin_lock(&engine->execlist_lock);
> 
> 	list_for_each_entry(cursor, &engine->execlist_queue, execlist_link)
> 		if (++num_elements > 2)
>@@ -595,7 +608,7 @@ static int execlists_context_queue(struct drm_i915_gem_request *request)
> 	if (num_elements == 0)
> 		execlists_context_unqueue(engine);
> 
>-	spin_unlock_irq(&engine->execlist_lock);
>+	spin_unlock(&engine->execlist_lock);
> 
> 	return 0;
> }
>@@ -648,9 +661,9 @@ void intel_execlists_retire_requests(struct intel_engine_cs *ring)
> 		return;
> 
> 	INIT_LIST_HEAD(&retired_list);
>-	spin_lock_irq(&ring->execlist_lock);
>+	spin_lock(&ring->execlist_lock);
> 	list_replace_init(&ring->execlist_retired_req_list, &retired_list);
>-	spin_unlock_irq(&ring->execlist_lock);
>+	spin_unlock(&ring->execlist_lock);
> 
> 	list_for_each_entry_safe(req, tmp, &retired_list, execlist_link) {
> 		struct intel_context *ctx = req->ctx;
>@@ -1494,6 +1507,9 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
> 	if (!intel_engine_initialized(ring))
> 		return;
> 
>+	if (ring->execlists_submit)
>+		kthread_stop(ring->execlists_submit);
>+
> 	if (ring->buffer) {
> 		struct drm_i915_private *dev_priv = ring->i915;
> 		intel_logical_ring_stop(ring);
>@@ -1519,13 +1535,15 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
> 
> static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *ring)
> {
>+	struct drm_i915_private *dev_priv = to_i915(dev);
>+	struct task_struct *task;
> 	int ret;
> 
> 	/* Intentionally left blank. */
> 	ring->buffer = NULL;
> 
> 	ring->dev = dev;
>-	ring->i915 = to_i915(dev);
>+	ring->i915 = dev_priv;
> 	ring->fence_context = fence_context_alloc(1);
> 	INIT_LIST_HEAD(&ring->request_list);
> 	i915_gem_batch_pool_init(dev, &ring->batch_pool);
>@@ -1556,6 +1574,15 @@ static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *rin
> 		goto error;
> 	}
> 
>+	ring->next_context_status_buffer =
>+			I915_READ(RING_CONTEXT_STATUS_PTR(ring)) & GEN8_CSB_PTR_MASK;
>+	task = kthread_run(intel_execlists_submit, ring,
>+			   "irq/i915:%de", ring->id);
>+	if (IS_ERR(task))
>+		goto error;
>+
>+	ring->execlists_submit = task;
>+
> 	return 0;
> 
> error:
>diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
>index fd88530ac540..635be05bd1e7 100644
>--- a/drivers/gpu/drm/i915/intel_lrc.h
>+++ b/drivers/gpu/drm/i915/intel_lrc.h
>@@ -70,7 +70,6 @@ int intel_execlists_submission(struct i915_execbuffer_params *params,
> 			       struct list_head *vmas);
> u32 intel_execlists_ctx_id(struct drm_i915_gem_object *ctx_obj);
> 
>-void intel_lrc_irq_handler(struct intel_engine_cs *ring);
> void intel_execlists_retire_requests(struct intel_engine_cs *ring);
> 
> #endif /* _INTEL_LRC_H_ */
>diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
>index 5b2cec3db78c..7a1940745880 100644
>--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
>+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
>@@ -283,6 +283,7 @@ struct intel_engine_cs {
> 	} semaphore;
> 
> 	/* Execlists */
>+	struct task_struct *execlists_submit;
> 	spinlock_t execlist_lock;
> 	struct list_head execlist_queue;
> 	struct list_head execlist_retired_req_list;
>-- 
>2.6.4
>

Actions: View | Splinter Review

Attachments on bug 93467: 120645

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.