From 3edd52bead30879644bb69fe4aafde67d2cd8512 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= Date: Wed, 27 Mar 2024 10:11:36 +0100 Subject: drm/xe: Move vma rebinding to the drm_exec locking loop MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rebinding might allocate page-table bos, causing evictions. To support blocking locking during these evictions, perform the rebinding in the drm_exec locking loop. Also Reserve fence slots where actually needed rather than trying to predict how many fence slots will be needed over a complete wound-wait transaction. v2: - Remove a leftover call to xe_vm_rebind() (Matt Brost) - Add a helper function xe_vm_validate_rebind() (Matt Brost) v3: - Add comments and squash with previous patch (Matt Brost) Fixes: 24f947d58fe5 ("drm/xe: Use DRM GPUVM helpers for external- and evicted objects") Fixes: 29f424eb8702 ("drm/xe/exec: move fence reservation") Cc: Matthew Auld Signed-off-by: Thomas Hellström Reviewed-by: Matthew Brost Link: https://patchwork.freedesktop.org/patch/msgid/20240327091136.3271-5-thomas.hellstrom@linux.intel.com (cherry picked from commit 7ee7dd6f301341d5b1204fc19fa620d7f7f7e90d) Signed-off-by: Lucas De Marchi --- drivers/gpu/drm/xe/xe_exec.c | 52 +++------------------- drivers/gpu/drm/xe/xe_gt_pagefault.c | 3 +- drivers/gpu/drm/xe/xe_pt.c | 14 ++++++ drivers/gpu/drm/xe/xe_vm.c | 83 +++++++++++++++++++++++++----------- drivers/gpu/drm/xe/xe_vm.h | 6 ++- 5 files changed, 83 insertions(+), 75 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_exec.c b/drivers/gpu/drm/xe/xe_exec.c index 79469b76a8be..cc5e0f75de3c 100644 --- a/drivers/gpu/drm/xe/xe_exec.c +++ b/drivers/gpu/drm/xe/xe_exec.c @@ -94,48 +94,16 @@ * Unlock all */ +/* + * Add validation and rebinding to the drm_exec locking loop, since both can + * trigger eviction which may require sleeping dma_resv locks. + */ static int xe_exec_fn(struct drm_gpuvm_exec *vm_exec) { struct xe_vm *vm = container_of(vm_exec->vm, struct xe_vm, gpuvm); - struct drm_gem_object *obj; - unsigned long index; - int num_fences; - int ret; - - ret = drm_gpuvm_validate(vm_exec->vm, &vm_exec->exec); - if (ret) - return ret; - - /* - * 1 fence slot for the final submit, and 1 more for every per-tile for - * GPU bind and 1 extra for CPU bind. Note that there are potentially - * many vma per object/dma-resv, however the fence slot will just be - * re-used, since they are largely the same timeline and the seqno - * should be in order. In the case of CPU bind there is dummy fence used - * for all CPU binds, so no need to have a per-tile slot for that. - */ - num_fences = 1 + 1 + vm->xe->info.tile_count; - /* - * We don't know upfront exactly how many fence slots we will need at - * the start of the exec, since the TTM bo_validate above can consume - * numerous fence slots. Also due to how the dma_resv_reserve_fences() - * works it only ensures that at least that many fence slots are - * available i.e if there are already 10 slots available and we reserve - * two more, it can just noop without reserving anything. With this it - * is quite possible that TTM steals some of the fence slots and then - * when it comes time to do the vma binding and final exec stage we are - * lacking enough fence slots, leading to some nasty BUG_ON() when - * adding the fences. Hence just add our own fences here, after the - * validate stage. - */ - drm_exec_for_each_locked_object(&vm_exec->exec, index, obj) { - ret = dma_resv_reserve_fences(obj->resv, num_fences); - if (ret) - return ret; - } - - return 0; + /* The fence slot added here is intended for the exec sched job. */ + return xe_vm_validate_rebind(vm, &vm_exec->exec, 1); } int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file) @@ -289,14 +257,6 @@ retry: goto err_exec; } - /* - * Rebind any invalidated userptr or evicted BOs in the VM, non-compute - * VM mode only. - */ - err = xe_vm_rebind(vm, false); - if (err) - goto err_put_job; - /* Wait behind rebinds */ if (!xe_vm_in_lr_mode(vm)) { err = drm_sched_job_add_resv_dependencies(&job->drm, diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c index 241c294270d9..fa9e9853c53b 100644 --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c @@ -100,10 +100,9 @@ static int xe_pf_begin(struct drm_exec *exec, struct xe_vma *vma, { struct xe_bo *bo = xe_vma_bo(vma); struct xe_vm *vm = xe_vma_vm(vma); - unsigned int num_shared = 2; /* slots for bind + move */ int err; - err = xe_vm_prepare_vma(exec, vma, num_shared); + err = xe_vm_lock_vma(exec, vma); if (err) return err; diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c index 29d1a31f9804..4efc8c1a3d7a 100644 --- a/drivers/gpu/drm/xe/xe_pt.c +++ b/drivers/gpu/drm/xe/xe_pt.c @@ -1235,6 +1235,13 @@ __xe_pt_bind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queue err = xe_pt_prepare_bind(tile, vma, entries, &num_entries); if (err) goto err; + + err = dma_resv_reserve_fences(xe_vm_resv(vm), 1); + if (!err && !xe_vma_has_no_bo(vma) && !xe_vma_bo(vma)->vm) + err = dma_resv_reserve_fences(xe_vma_bo(vma)->ttm.base.resv, 1); + if (err) + goto err; + xe_tile_assert(tile, num_entries <= ARRAY_SIZE(entries)); xe_vm_dbg_print_entries(tile_to_xe(tile), entries, num_entries); @@ -1577,6 +1584,7 @@ __xe_pt_unbind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queu struct dma_fence *fence = NULL; struct invalidation_fence *ifence; struct xe_range_fence *rfence; + int err; LLIST_HEAD(deferred); @@ -1594,6 +1602,12 @@ __xe_pt_unbind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queu xe_pt_calc_rfence_interval(vma, &unbind_pt_update, entries, num_entries); + err = dma_resv_reserve_fences(xe_vm_resv(vm), 1); + if (!err && !xe_vma_has_no_bo(vma) && !xe_vma_bo(vma)->vm) + err = dma_resv_reserve_fences(xe_vma_bo(vma)->ttm.base.resv, 1); + if (err) + return ERR_PTR(err); + ifence = kzalloc(sizeof(*ifence), GFP_KERNEL); if (!ifence) return ERR_PTR(-ENOMEM); diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c index 3b97e9c92609..62d1ef8867a8 100644 --- a/drivers/gpu/drm/xe/xe_vm.c +++ b/drivers/gpu/drm/xe/xe_vm.c @@ -482,17 +482,53 @@ static int xe_gpuvm_validate(struct drm_gpuvm_bo *vm_bo, struct drm_exec *exec) return 0; } +/** + * xe_vm_validate_rebind() - Validate buffer objects and rebind vmas + * @vm: The vm for which we are rebinding. + * @exec: The struct drm_exec with the locked GEM objects. + * @num_fences: The number of fences to reserve for the operation, not + * including rebinds and validations. + * + * Validates all evicted gem objects and rebinds their vmas. Note that + * rebindings may cause evictions and hence the validation-rebind + * sequence is rerun until there are no more objects to validate. + * + * Return: 0 on success, negative error code on error. In particular, + * may return -EINTR or -ERESTARTSYS if interrupted, and -EDEADLK if + * the drm_exec transaction needs to be restarted. + */ +int xe_vm_validate_rebind(struct xe_vm *vm, struct drm_exec *exec, + unsigned int num_fences) +{ + struct drm_gem_object *obj; + unsigned long index; + int ret; + + do { + ret = drm_gpuvm_validate(&vm->gpuvm, exec); + if (ret) + return ret; + + ret = xe_vm_rebind(vm, false); + if (ret) + return ret; + } while (!list_empty(&vm->gpuvm.evict.list)); + + drm_exec_for_each_locked_object(exec, index, obj) { + ret = dma_resv_reserve_fences(obj->resv, num_fences); + if (ret) + return ret; + } + + return 0; +} + static int xe_preempt_work_begin(struct drm_exec *exec, struct xe_vm *vm, bool *done) { int err; - /* - * 1 fence for each preempt fence plus a fence for each tile from a - * possible rebind - */ - err = drm_gpuvm_prepare_vm(&vm->gpuvm, exec, vm->preempt.num_exec_queues + - vm->xe->info.tile_count); + err = drm_gpuvm_prepare_vm(&vm->gpuvm, exec, 0); if (err) return err; @@ -507,7 +543,7 @@ static int xe_preempt_work_begin(struct drm_exec *exec, struct xe_vm *vm, return 0; } - err = drm_gpuvm_prepare_objects(&vm->gpuvm, exec, vm->preempt.num_exec_queues); + err = drm_gpuvm_prepare_objects(&vm->gpuvm, exec, 0); if (err) return err; @@ -515,7 +551,13 @@ static int xe_preempt_work_begin(struct drm_exec *exec, struct xe_vm *vm, if (err) return err; - return drm_gpuvm_validate(&vm->gpuvm, exec); + /* + * Add validation and rebinding to the locking loop since both can + * cause evictions which may require blocing dma_resv locks. + * The fence reservation here is intended for the new preempt fences + * we attach at the end of the rebind work. + */ + return xe_vm_validate_rebind(vm, exec, vm->preempt.num_exec_queues); } static void preempt_rebind_work_func(struct work_struct *w) @@ -996,35 +1038,26 @@ static void xe_vma_destroy(struct xe_vma *vma, struct dma_fence *fence) } /** - * xe_vm_prepare_vma() - drm_exec utility to lock a vma + * xe_vm_lock_vma() - drm_exec utility to lock a vma * @exec: The drm_exec object we're currently locking for. * @vma: The vma for witch we want to lock the vm resv and any attached * object's resv. - * @num_shared: The number of dma-fence slots to pre-allocate in the - * objects' reservation objects. * * Return: 0 on success, negative error code on error. In particular * may return -EDEADLK on WW transaction contention and -EINTR if * an interruptible wait is terminated by a signal. */ -int xe_vm_prepare_vma(struct drm_exec *exec, struct xe_vma *vma, - unsigned int num_shared) +int xe_vm_lock_vma(struct drm_exec *exec, struct xe_vma *vma) { struct xe_vm *vm = xe_vma_vm(vma); struct xe_bo *bo = xe_vma_bo(vma); int err; XE_WARN_ON(!vm); - if (num_shared) - err = drm_exec_prepare_obj(exec, xe_vm_obj(vm), num_shared); - else - err = drm_exec_lock_obj(exec, xe_vm_obj(vm)); - if (!err && bo && !bo->vm) { - if (num_shared) - err = drm_exec_prepare_obj(exec, &bo->ttm.base, num_shared); - else - err = drm_exec_lock_obj(exec, &bo->ttm.base); - } + + err = drm_exec_lock_obj(exec, xe_vm_obj(vm)); + if (!err && bo && !bo->vm) + err = drm_exec_lock_obj(exec, &bo->ttm.base); return err; } @@ -1036,7 +1069,7 @@ static void xe_vma_destroy_unlocked(struct xe_vma *vma) drm_exec_init(&exec, 0, 0); drm_exec_until_all_locked(&exec) { - err = xe_vm_prepare_vma(&exec, vma, 0); + err = xe_vm_lock_vma(&exec, vma); drm_exec_retry_on_contention(&exec); if (XE_WARN_ON(err)) break; @@ -2503,7 +2536,7 @@ static int op_execute(struct drm_exec *exec, struct xe_vm *vm, lockdep_assert_held_write(&vm->lock); - err = xe_vm_prepare_vma(exec, vma, 1); + err = xe_vm_lock_vma(exec, vma); if (err) return err; diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h index 4853354336f2..306cd0934a19 100644 --- a/drivers/gpu/drm/xe/xe_vm.h +++ b/drivers/gpu/drm/xe/xe_vm.h @@ -242,8 +242,10 @@ bool xe_vm_validate_should_retry(struct drm_exec *exec, int err, ktime_t *end); int xe_analyze_vm(struct drm_printer *p, struct xe_vm *vm, int gt_id); -int xe_vm_prepare_vma(struct drm_exec *exec, struct xe_vma *vma, - unsigned int num_shared); +int xe_vm_lock_vma(struct drm_exec *exec, struct xe_vma *vma); + +int xe_vm_validate_rebind(struct xe_vm *vm, struct drm_exec *exec, + unsigned int num_fences); /** * xe_vm_resv() - Return's the vm's reservation object -- cgit v1.2.3