[PATCH v5 4/7] drm/xe: Convert multiple bind ops into single job

Matthew Brost matthew.brost at intel.com
Thu Jun 27 06:11:12 UTC 2024


On Wed, Jun 26, 2024 at 03:03:41PM +0100, Matthew Auld wrote:
> On 26/06/2024 01:39, Matthew Brost wrote:
> > This aligns with the uAPI of an array of binds or single bind that
> > results in multiple GPUVA ops to be considered a single atomic
> > operations.
> > 
> > The implemenation is roughly:
> > - xe_vma_ops is a list of xe_vma_op (GPUVA op)
> > - each xe_vma_op resolves to 0-3 PT ops
> > - xe_vma_ops creates a single job
> > - if at any point during binding a failure occurs, xe_vma_ops contains
> >    the information necessary unwind the PT and VMA (GPUVA) state
> > 
> > v2:
> >   - add missing dma-resv slot reservation (CI, testing)
> > v4:
> >   - Fix TLB invalidation (Paulo)
> >   - Add missing xe_sched_job_last_fence_add/test_dep check (Inspection)
> > v5:
> >   - Invert i, j usage (Matthew Auld)
> >   - Add helper to test and add job dep (Matthew Auld)
> >   - Return on anything but -ETIME for cpu bind (Matthew Auld)
> >   - Return -ENOBUFS if suballoc of BB fails due to size (Matthew Auld)
> >   - s/do/Do (Matthew Auld)
> >   - Add missing comma (Matthew Auld)
> >   - Do not assign return value to xe_range_fence_insert (Matthew Auld)
> > 
> > Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> >   drivers/gpu/drm/xe/xe_bo_types.h |    2 +
> >   drivers/gpu/drm/xe/xe_migrate.c  |  306 ++++-----
> >   drivers/gpu/drm/xe/xe_migrate.h  |   32 +-
> >   drivers/gpu/drm/xe/xe_pt.c       | 1102 +++++++++++++++++++-----------
> >   drivers/gpu/drm/xe/xe_pt.h       |   14 +-
> >   drivers/gpu/drm/xe/xe_pt_types.h |   36 +
> >   drivers/gpu/drm/xe/xe_vm.c       |  519 +++-----------
> >   drivers/gpu/drm/xe/xe_vm.h       |    2 +
> >   drivers/gpu/drm/xe/xe_vm_types.h |   45 +-
> >   9 files changed, 1036 insertions(+), 1022 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_bo_types.h b/drivers/gpu/drm/xe/xe_bo_types.h
> > index 86422e113d39..02d68873558a 100644
> > --- a/drivers/gpu/drm/xe/xe_bo_types.h
> > +++ b/drivers/gpu/drm/xe/xe_bo_types.h
> > @@ -58,6 +58,8 @@ struct xe_bo {
> >   #endif
> >   	/** @freed: List node for delayed put. */
> >   	struct llist_node freed;
> > +	/** @update_index: Update index if PT BO */
> > +	int update_index;
> >   	/** @created: Whether the bo has passed initial creation */
> >   	bool created;
> > diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
> > index af62783d34ac..160bfcd510ae 100644
> > --- a/drivers/gpu/drm/xe/xe_migrate.c
> > +++ b/drivers/gpu/drm/xe/xe_migrate.c
> > @@ -1125,6 +1125,7 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
> >   }
> >   static void write_pgtable(struct xe_tile *tile, struct xe_bb *bb, u64 ppgtt_ofs,
> > +			  const struct xe_vm_pgtable_update_op *pt_op,
> >   			  const struct xe_vm_pgtable_update *update,
> >   			  struct xe_migrate_pt_update *pt_update)
> >   {
> > @@ -1159,8 +1160,12 @@ static void write_pgtable(struct xe_tile *tile, struct xe_bb *bb, u64 ppgtt_ofs,
> >   		bb->cs[bb->len++] = MI_STORE_DATA_IMM | MI_SDI_NUM_QW(chunk);
> >   		bb->cs[bb->len++] = lower_32_bits(addr);
> >   		bb->cs[bb->len++] = upper_32_bits(addr);
> > -		ops->populate(pt_update, tile, NULL, bb->cs + bb->len, ofs, chunk,
> > -			      update);
> > +		if (pt_op->bind)
> > +			ops->populate(pt_update, tile, NULL, bb->cs + bb->len,
> > +				      ofs, chunk, update);
> > +		else
> > +			ops->clear(pt_update, tile, NULL, bb->cs + bb->len,
> > +				   ofs, chunk, update);
> >   		bb->len += chunk * 2;
> >   		ofs += chunk;
> > @@ -1185,114 +1190,58 @@ struct migrate_test_params {
> >   static struct dma_fence *
> >   xe_migrate_update_pgtables_cpu(struct xe_migrate *m,
> > -			       struct xe_vm *vm, struct xe_bo *bo,
> > -			       const struct  xe_vm_pgtable_update *updates,
> > -			       u32 num_updates, bool wait_vm,
> >   			       struct xe_migrate_pt_update *pt_update)
> >   {
> >   	XE_TEST_DECLARE(struct migrate_test_params *test =
> >   			to_migrate_test_params
> >   			(xe_cur_kunit_priv(XE_TEST_LIVE_MIGRATE));)
> >   	const struct xe_migrate_pt_update_ops *ops = pt_update->ops;
> > -	struct dma_fence *fence;
> > +	struct xe_vm *vm = pt_update->vops->vm;
> > +	struct xe_vm_pgtable_update_ops *pt_update_ops =
> > +		&pt_update->vops->pt_update_ops[pt_update->tile_id];
> >   	int err;
> > -	u32 i;
> > +	u32 i, j;
> >   	if (XE_TEST_ONLY(test && test->force_gpu))
> >   		return ERR_PTR(-ETIME);
> > -	if (bo && !dma_resv_test_signaled(bo->ttm.base.resv,
> > -					  DMA_RESV_USAGE_KERNEL))
> > -		return ERR_PTR(-ETIME);
> > -
> > -	if (wait_vm && !dma_resv_test_signaled(xe_vm_resv(vm),
> > -					       DMA_RESV_USAGE_BOOKKEEP))
> > -		return ERR_PTR(-ETIME);
> > -
> >   	if (ops->pre_commit) {
> >   		pt_update->job = NULL;
> >   		err = ops->pre_commit(pt_update);
> >   		if (err)
> >   			return ERR_PTR(err);
> >   	}
> > -	for (i = 0; i < num_updates; i++) {
> > -		const struct xe_vm_pgtable_update *update = &updates[i];
> > -
> > -		ops->populate(pt_update, m->tile, &update->pt_bo->vmap, NULL,
> > -			      update->ofs, update->qwords, update);
> > -	}
> > -
> > -	if (vm) {
> > -		trace_xe_vm_cpu_bind(vm);
> > -		xe_device_wmb(vm->xe);
> > -	}
> > -
> > -	fence = dma_fence_get_stub();
> > -
> > -	return fence;
> > -}
> > -
> > -static bool no_in_syncs(struct xe_vm *vm, struct xe_exec_queue *q,
> > -			struct xe_sync_entry *syncs, u32 num_syncs)
> > -{
> > -	struct dma_fence *fence;
> > -	int i;
> > -	for (i = 0; i < num_syncs; i++) {
> > -		fence = syncs[i].fence;
> > -
> > -		if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
> > -				       &fence->flags))
> > -			return false;
> > -	}
> > -	if (q) {
> > -		fence = xe_exec_queue_last_fence_get(q, vm);
> > -		if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
> > -			dma_fence_put(fence);
> > -			return false;
> > +	for (i = 0; i < pt_update_ops->num_ops; ++i) {
> > +		const struct xe_vm_pgtable_update_op *pt_op =
> > +			&pt_update_ops->ops[i];
> > +
> > +		for (j = 0; j < pt_op->num_entries; j++) {
> > +			const struct xe_vm_pgtable_update *update =
> > +				&pt_op->entries[j];
> > +
> > +			if (pt_op->bind)
> > +				ops->populate(pt_update, m->tile,
> > +					      &update->pt_bo->vmap, NULL,
> > +					      update->ofs, update->qwords,
> > +					      update);
> > +			else
> > +				ops->clear(pt_update, m->tile,
> > +					   &update->pt_bo->vmap, NULL,
> > +					   update->ofs, update->qwords, update);
> >   		}
> > -		dma_fence_put(fence);
> >   	}
> > -	return true;
> > +	trace_xe_vm_cpu_bind(vm);
> > +	xe_device_wmb(vm->xe);
> > +
> > +	return dma_fence_get_stub();
> >   }
> > -/**
> > - * xe_migrate_update_pgtables() - Pipelined page-table update
> > - * @m: The migrate context.
> > - * @vm: The vm we'll be updating.
> > - * @bo: The bo whose dma-resv we will await before updating, or NULL if userptr.
> > - * @q: The exec queue to be used for the update or NULL if the default
> > - * migration engine is to be used.
> > - * @updates: An array of update descriptors.
> > - * @num_updates: Number of descriptors in @updates.
> > - * @syncs: Array of xe_sync_entry to await before updating. Note that waits
> > - * will block the engine timeline.
> > - * @num_syncs: Number of entries in @syncs.
> > - * @pt_update: Pointer to a struct xe_migrate_pt_update, which contains
> > - * pointers to callback functions and, if subclassed, private arguments to
> > - * those.
> > - *
> > - * Perform a pipelined page-table update. The update descriptors are typically
> > - * built under the same lock critical section as a call to this function. If
> > - * using the default engine for the updates, they will be performed in the
> > - * order they grab the job_mutex. If different engines are used, external
> > - * synchronization is needed for overlapping updates to maintain page-table
> > - * consistency. Note that the meaing of "overlapping" is that the updates
> > - * touch the same page-table, which might be a higher-level page-directory.
> > - * If no pipelining is needed, then updates may be performed by the cpu.
> > - *
> > - * Return: A dma_fence that, when signaled, indicates the update completion.
> > - */
> > -struct dma_fence *
> > -xe_migrate_update_pgtables(struct xe_migrate *m,
> > -			   struct xe_vm *vm,
> > -			   struct xe_bo *bo,
> > -			   struct xe_exec_queue *q,
> > -			   const struct xe_vm_pgtable_update *updates,
> > -			   u32 num_updates,
> > -			   struct xe_sync_entry *syncs, u32 num_syncs,
> > -			   struct xe_migrate_pt_update *pt_update)
> > +static struct dma_fence *
> > +__xe_migrate_update_pgtables(struct xe_migrate *m,
> > +			     struct xe_migrate_pt_update *pt_update,
> > +			     struct xe_vm_pgtable_update_ops *pt_update_ops)
> >   {
> >   	const struct xe_migrate_pt_update_ops *ops = pt_update->ops;
> >   	struct xe_tile *tile = m->tile;
> > @@ -1301,59 +1250,53 @@ xe_migrate_update_pgtables(struct xe_migrate *m,
> >   	struct xe_sched_job *job;
> >   	struct dma_fence *fence;
> >   	struct drm_suballoc *sa_bo = NULL;
> > -	struct xe_vma *vma = pt_update->vma;
> >   	struct xe_bb *bb;
> > -	u32 i, batch_size, ppgtt_ofs, update_idx, page_ofs = 0;
> > +	u32 i, j, batch_size = 0, ppgtt_ofs, update_idx, page_ofs = 0;
> > +	u32 num_updates = 0, current_update = 0;
> >   	u64 addr;
> >   	int err = 0;
> > -	bool usm = !q && xe->info.has_usm;
> > -	bool first_munmap_rebind = vma &&
> > -		vma->gpuva.flags & XE_VMA_FIRST_REBIND;
> > -	struct xe_exec_queue *q_override = !q ? m->q : q;
> > -	u16 pat_index = xe->pat.idx[XE_CACHE_WB];
> > +	bool is_migrate = pt_update_ops->q == m->q;
> > +	bool usm = is_migrate && xe->info.has_usm;
> > +
> > +	for (i = 0; i < pt_update_ops->num_ops; ++i) {
> > +		struct xe_vm_pgtable_update_op *pt_op = &pt_update_ops->ops[i];
> > +		struct xe_vm_pgtable_update *updates = pt_op->entries;
> > -	/* Use the CPU if no in syncs and engine is idle */
> > -	if (no_in_syncs(vm, q, syncs, num_syncs) && xe_exec_queue_is_idle(q_override)) {
> > -		fence =  xe_migrate_update_pgtables_cpu(m, vm, bo, updates,
> > -							num_updates,
> > -							first_munmap_rebind,
> > -							pt_update);
> > -		if (!IS_ERR(fence) || fence == ERR_PTR(-EAGAIN))
> > -			return fence;
> > +		num_updates += pt_op->num_entries;
> > +		for (j = 0; j < pt_op->num_entries; ++j) {
> > +			u32 num_cmds = DIV_ROUND_UP(updates[j].qwords, 0x1ff);
> 
> Why 0x1ff here? Should it not be MAX_PTE_PER_SDI? There is a failure in CI
> here: https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-133034v5/shard-lnl-8/igt@xe_vm@mmap-style-bind-either-side-partial-split-page-hammer.html
> 
> Wondering if this is the cause? i.e we think we can fit more stores per
> MI_STORE_DATA_IMM, since write_pgtable() below is using MAX_PTE_PER_SDI and
> not 0x1ff?
> 

This indeed was the source of the CI failure, could easily create this
on TGL too. Thanks for catching this.

Matt

> > +
> > +			/* align noop + MI_STORE_DATA_IMM cmd prefix */
> > +			batch_size += 4 * num_cmds + updates[j].qwords * 2;
> > +		}
> >   	}
> >   	/* fixed + PTE entries */
> >   	if (IS_DGFX(xe))
> > -		batch_size = 2;
> > +		batch_size += 2;
> >   	else
> > -		batch_size = 6 + num_updates * 2;
> > -
> > -	for (i = 0; i < num_updates; i++) {
> > -		u32 num_cmds = DIV_ROUND_UP(updates[i].qwords, MAX_PTE_PER_SDI);
> > +		batch_size += 6 + num_updates * 2;
> > -		/* align noop + MI_STORE_DATA_IMM cmd prefix */
> > -		batch_size += 4 * num_cmds + updates[i].qwords * 2;
> > -	}
> > -
> > -	/*
> > -	 * XXX: Create temp bo to copy from, if batch_size becomes too big?
> > -	 *
> > -	 * Worst case: Sum(2 * (each lower level page size) + (top level page size))
> > -	 * Should be reasonably bound..
> > -	 */
> > -	xe_tile_assert(tile, batch_size < SZ_128K);
> > +	bb = xe_bb_new(gt, batch_size, usm);
> 
> So do we now validate that batch_size fits within the total pool size
> somewhere, to avoid triggering the warning in drm_suballoc_new? Did your igt
> not trigger the warning? Also the below check is not too late?
> 
> > +	if (IS_ERR(bb)) {
> > +		/*
> > +		 * BB to large, return -ENOBUFS indicating user should split
> > +		 * array of binds into smaller chunks.
> > +		 */
> > +		if (PTR_ERR(bb) == -EINVAL)
> > +			return ERR_PTR(-ENOBUFS);
> > -	bb = xe_bb_new(gt, batch_size, !q && xe->info.has_usm);
> > -	if (IS_ERR(bb))
> >   		return ERR_CAST(bb);
> > +	}
> >   	/* For sysmem PTE's, need to map them in our hole.. */
> >   	if (!IS_DGFX(xe)) {
> >   		ppgtt_ofs = NUM_KERNEL_PDE - 1;
> > -		if (q) {
> > -			xe_tile_assert(tile, num_updates <= NUM_VMUSA_WRITES_PER_UNIT);
> > +		if (!is_migrate) {
> > +			u32 num_units = DIV_ROUND_UP(num_updates,
> > +						     NUM_VMUSA_WRITES_PER_UNIT);
> > -			sa_bo = drm_suballoc_new(&m->vm_update_sa, 1,
> > +			sa_bo = drm_suballoc_new(&m->vm_update_sa, num_units,
> >   						 GFP_KERNEL, true, 0);
> 
> And maybe here also?
> 
> >   			if (IS_ERR(sa_bo)) {
> >   				err = PTR_ERR(sa_bo);
> > @@ -1373,14 +1316,26 @@ xe_migrate_update_pgtables(struct xe_migrate *m,
> >   		bb->cs[bb->len++] = ppgtt_ofs * XE_PAGE_SIZE + page_ofs;
> >   		bb->cs[bb->len++] = 0; /* upper_32_bits */
> 
> Off camera this is doing:
> 
> b->cs[bb->len++] = MI_STORE_DATA_IMM | MI_SDI_NUM_QW(num_updates);
> 
> What are certain that num_updates still can be done with single command
> here?  Do we not need to break it up like we do with write_pgtable? If it's
> not an issue I think would be good to add an assert to ensure it fits?
> 
> <snip>


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