[PATCH 3/6] drm/amdgpu: Flush VM updates for split bindings eagerly.
Lang Yu
Lang.Yu at amd.com
Thu Nov 2 02:36:26 UTC 2023
On 10/31/ , Christian König wrote:
> Am 31.10.23 um 14:59 schrieb Bas Nieuwenhuizen:
> >
> >
> > On Tue, Oct 31, 2023 at 2:57 PM Christian König
> > <christian.koenig at amd.com> wrote:
> >
> > Am 31.10.23 um 14:40 schrieb Tatsuyuki Ishi:
> > > The current amdgpu_gem_va_update_vm only tries to perform
> > updates for the
> > > BO specified in the GEM ioctl; however, when a binding is split, the
> > > adjacent bindings also need to be updated. Such updates
> > currently ends up
> > > getting deferred until next submission which causes stalls.
> >
> > Yeah, that is a necessity. The hardware simply doesn't support
> > what you
> > try to do here in all cases.
> >
> >
> > What can the hardware not do here? Is this just needing to wait for TLB
> > flushes before we can free pagetables, can we just delay that?
>
> On some hardware generations (especially Navi1x, but also everything older
> than Polaris) you can't invalidate the TLB while it is in use.
Hi Christian,
non-legacy invalidation can invalidate the TLB while it is in use.
Right? Thanks.
Regards,
Lang
> For Polaris and older it just means that you don't have a guarantee that the
> shader can't access the memory any more. So delaying the free operation
> helps here.
>
> But for Navi1x it's a workaround for a hardware bug. If you try to
> invalidate the TLB while it is in use you can potentially triggering memory
> accesses to random addresses.
>
> That's why we still delay TLB invalidation's to the next CS and use a new
> VMID for each submission instead of invalidating the old one.
>
> I'm currently working on changing that for Navi2x and newer (maybe Vega as
> well), but this is something you can really only do on some hw generations
> after validating that it works.
>
> Regards,
> Christian.
>
> >
> >
> > So this approach won't work in general.
> >
> > Regards,
> > Christian.
> >
> > >
> > > Introduce a new state "dirty", shared between per-VM BOs and
> > traditional
> > > BOs, containing all BOs that have pending updates in `invalids`.
> > > amdgpu_gem_va_update_vm will now simply flush any pending
> > updates for BOs
> > > in the dirty state.
> > >
> > > Signed-off-by: Tatsuyuki Ishi <ishitatsuyuki at gmail.com>
> > > ---
> > > drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 18 ++++---
> > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 66
> > ++++++++++++++++++-------
> > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 3 ++
> > > 3 files changed, 63 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> > > index a1b15d0d6c48..01d3a97248b0 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> > > @@ -604,10 +604,9 @@ int amdgpu_gem_metadata_ioctl(struct
> > drm_device *dev, void *data,
> > > * vital here, so they are not reported back to userspace.
> > > */
> > > static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
> > > - struct amdgpu_vm *vm,
> > > - struct amdgpu_bo_va *bo_va,
> > > - uint32_t operation)
> > > + struct amdgpu_vm *vm)
> > > {
> > > + struct amdgpu_bo_va *bo_va;
> > > int r;
> > >
> > > if (!amdgpu_vm_ready(vm))
> > > @@ -617,12 +616,18 @@ static void amdgpu_gem_va_update_vm(struct
> > amdgpu_device *adev,
> > > if (r)
> > > goto error;
> > >
> > > - if (operation == AMDGPU_VA_OP_MAP ||
> > > - operation == AMDGPU_VA_OP_REPLACE) {
> > > + spin_lock(&vm->status_lock);
> > > + while (!list_empty(&vm->dirty)) {
> > > + bo_va = list_first_entry(&vm->dirty, struct
> > amdgpu_bo_va,
> > > + base.vm_status);
> > > + spin_unlock(&vm->status_lock);
> > > +
> > > r = amdgpu_vm_bo_update(adev, bo_va, false);
> > > if (r)
> > > goto error;
> > > + spin_lock(&vm->status_lock);
> > > }
> > > + spin_unlock(&vm->status_lock);
> > >
> > > r = amdgpu_vm_update_pdes(adev, vm, false);
> > >
> > > @@ -792,8 +797,7 @@ int amdgpu_gem_va_ioctl(struct drm_device
> > *dev, void *data,
> > > break;
> > > }
> > > if (!r && !(args->flags & AMDGPU_VM_DELAY_UPDATE) &&
> > !amdgpu_vm_debug)
> > > - amdgpu_gem_va_update_vm(adev, &fpriv->vm, bo_va,
> > > - args->operation);
> > > + amdgpu_gem_va_update_vm(adev, &fpriv->vm);
> > >
> > > error:
> > > drm_exec_fini(&exec);
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > index dd6f72e2a1d6..01d31891cd05 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > @@ -191,6 +191,21 @@ static void amdgpu_vm_bo_set_evicted(struct
> > amdgpu_vm_bo_base *vm_bo, bool evict
> > > spin_unlock(&vm_bo->vm->status_lock);
> > > }
> > >
> > > +/**
> > > + * amdgpu_vm_bo_dirty - vm_bo is dirty
> > > + *
> > > + * @vm_bo: vm_bo which is dirty
> > > + *
> > > + * State for normal and per VM BOs that are not moved, but have
> > new entries in
> > > + * bo_va->invalids.
> > > + */
> > > +static void amdgpu_vm_bo_dirty(struct amdgpu_vm_bo_base *vm_bo)
> > > +{
> > > + spin_lock(&vm_bo->vm->status_lock);
> > > + list_move(&vm_bo->vm_status, &vm_bo->vm->dirty);
> > > + spin_unlock(&vm_bo->vm->status_lock);
> > > +}
> > > +
> > > /**
> > > * amdgpu_vm_bo_moved - vm_bo is moved
> > > *
> > > @@ -1042,6 +1057,9 @@ void amdgpu_vm_get_memory(struct amdgpu_vm
> > *vm,
> > > list_for_each_entry_safe(bo_va, tmp, &vm->evicted,
> > base.eviction_status)
> > > amdgpu_vm_bo_get_memory(bo_va, stats);
> > >
> > > + list_for_each_entry_safe(bo_va, tmp, &vm->dirty,
> > base.vm_status)
> > > + amdgpu_vm_bo_get_memory(bo_va, stats);
> > > +
> > > list_for_each_entry_safe(bo_va, tmp, &vm->relocated,
> > base.vm_status)
> > > amdgpu_vm_bo_get_memory(bo_va, stats);
> > >
> > > @@ -1411,6 +1429,17 @@ int amdgpu_vm_handle_moved(struct
> > amdgpu_device *adev,
> > > dma_resv_unlock(resv);
> > > spin_lock(&vm->status_lock);
> > > }
> > > +
> > > + while (!list_empty(&vm->dirty)) {
> > > + bo_va = list_first_entry(&vm->dirty, struct
> > amdgpu_bo_va,
> > > + base.vm_status);
> > > + spin_unlock(&vm->status_lock);
> > > +
> > > + r = amdgpu_vm_bo_update(adev, bo_va, false);
> > > + if (r)
> > > + return r;
> > > + spin_lock(&vm->status_lock);
> > > + }
> > > spin_unlock(&vm->status_lock);
> > >
> > > return 0;
> > > @@ -1476,19 +1505,16 @@ static void
> > amdgpu_vm_bo_insert_map(struct amdgpu_device *adev,
> > > struct amdgpu_bo_va_mapping
> > *mapping)
> > > {
> > > struct amdgpu_vm *vm = bo_va->base.vm;
> > > - struct amdgpu_bo *bo = bo_va->base.bo <http://base.bo>;
> > >
> > > mapping->bo_va = bo_va;
> > > list_add(&mapping->list, &bo_va->invalids);
> > > amdgpu_vm_it_insert(mapping, &vm->va);
> > > + if (!bo_va->base.moved)
> > > + amdgpu_vm_bo_dirty(&bo_va->base);
> > >
> > > if (mapping->flags & AMDGPU_PTE_PRT)
> > > amdgpu_vm_prt_get(adev);
> > >
> > > - if (bo && bo->tbo.base.resv == vm->root.bo->tbo.base.resv &&
> > > - !bo_va->base.moved) {
> > > - amdgpu_vm_bo_moved(&bo_va->base);
> > > - }
> > > trace_amdgpu_vm_bo_map(bo_va, mapping);
> > > }
> > >
> > > @@ -1725,6 +1751,8 @@ int amdgpu_vm_bo_clear_mappings(struct
> > amdgpu_device *adev,
> > > before->flags = tmp->flags;
> > > before->bo_va = tmp->bo_va;
> > > list_add(&before->list,
> > &tmp->bo_va->invalids);
> > > + if (!tmp->bo_va->base.moved)
> > > + amdgpu_vm_bo_dirty(&tmp->bo_va->base);
> > > }
> > >
> > > /* Remember mapping split at the end */
> > > @@ -1736,6 +1764,8 @@ int amdgpu_vm_bo_clear_mappings(struct
> > amdgpu_device *adev,
> > > after->flags = tmp->flags;
> > > after->bo_va = tmp->bo_va;
> > > list_add(&after->list, &tmp->bo_va->invalids);
> > > + if (!tmp->bo_va->base.moved)
> > > + amdgpu_vm_bo_dirty(&tmp->bo_va->base);
> > > }
> > >
> > > list_del(&tmp->list);
> > > @@ -1761,30 +1791,18 @@ int amdgpu_vm_bo_clear_mappings(struct
> > amdgpu_device *adev,
> > >
> > > /* Insert partial mapping before the range */
> > > if (!list_empty(&before->list)) {
> > > - struct amdgpu_bo *bo = before->bo_va->base.bo
> > <http://base.bo>;
> > > -
> > > amdgpu_vm_it_insert(before, &vm->va);
> > > if (before->flags & AMDGPU_PTE_PRT)
> > > amdgpu_vm_prt_get(adev);
> > > -
> > > - if (bo && bo->tbo.base.resv ==
> > vm->root.bo->tbo.base.resv &&
> > > - !before->bo_va->base.moved)
> > > - amdgpu_vm_bo_moved(&before->bo_va->base);
> > > } else {
> > > kfree(before);
> > > }
> > >
> > > /* Insert partial mapping after the range */
> > > if (!list_empty(&after->list)) {
> > > - struct amdgpu_bo *bo = after->bo_va->base.bo
> > <http://base.bo>;
> > > -
> > > amdgpu_vm_it_insert(after, &vm->va);
> > > if (after->flags & AMDGPU_PTE_PRT)
> > > amdgpu_vm_prt_get(adev);
> > > -
> > > - if (bo && bo->tbo.base.resv ==
> > vm->root.bo->tbo.base.resv &&
> > > - !after->bo_va->base.moved)
> > > - amdgpu_vm_bo_moved(&after->bo_va->base);
> > > } else {
> > > kfree(after);
> > > }
> > > @@ -2136,6 +2154,7 @@ int amdgpu_vm_init(struct amdgpu_device
> > *adev, struct amdgpu_vm *vm, int32_t xcp
> > > INIT_LIST_HEAD(&vm->evicted);
> > > INIT_LIST_HEAD(&vm->relocated);
> > > INIT_LIST_HEAD(&vm->moved);
> > > + INIT_LIST_HEAD(&vm->dirty);
> > > INIT_LIST_HEAD(&vm->idle);
> > > INIT_LIST_HEAD(&vm->invalidated);
> > > spin_lock_init(&vm->status_lock);
> > > @@ -2648,11 +2667,13 @@ void amdgpu_debugfs_vm_bo_info(struct
> > amdgpu_vm *vm, struct seq_file *m)
> > > {
> > > struct amdgpu_bo_va *bo_va, *tmp;
> > > u64 total_idle = 0;
> > > + u64 total_dirty = 0;
> > > u64 total_relocated = 0;
> > > u64 total_moved = 0;
> > > u64 total_invalidated = 0;
> > > u64 total_done = 0;
> > > unsigned int total_idle_objs = 0;
> > > + unsigned int total_dirty_objs = 0;
> > > unsigned int total_relocated_objs = 0;
> > > unsigned int total_moved_objs = 0;
> > > unsigned int total_invalidated_objs = 0;
> > > @@ -2669,6 +2690,15 @@ void amdgpu_debugfs_vm_bo_info(struct
> > amdgpu_vm *vm, struct seq_file *m)
> > > total_idle_objs = id;
> > > id = 0;
> > >
> > > + seq_puts(m, "\tDirty BOs:\n");
> > > + list_for_each_entry_safe(bo_va, tmp, &vm->dirty,
> > base.vm_status) {
> > > + if (!bo_va->base.bo <http://base.bo>)
> > > + continue;
> > > + total_dirty += amdgpu_bo_print_info(id++,
> > bo_va->base.bo <http://base.bo>, m);
> > > + }
> > > + total_dirty_objs = id;
> > > + id = 0;
> > > +
> > > seq_puts(m, "\tRelocated BOs:\n");
> > > list_for_each_entry_safe(bo_va, tmp, &vm->relocated,
> > base.vm_status) {
> > > if (!bo_va->base.bo <http://base.bo>)
> > > @@ -2707,6 +2737,8 @@ void amdgpu_debugfs_vm_bo_info(struct
> > amdgpu_vm *vm, struct seq_file *m)
> > >
> > > seq_printf(m, "\tTotal idle size: %12lld\tobjs:\t%d\n",
> > total_idle,
> > > total_idle_objs);
> > > + seq_printf(m, "\tTotal dirty size: %12lld\tobjs:\t%d\n",
> > total_dirty,
> > > + total_dirty_objs);
> > > seq_printf(m, "\tTotal relocated size:
> > %12lld\tobjs:\t%d\n", total_relocated,
> > > total_relocated_objs);
> > > seq_printf(m, "\tTotal moved size: %12lld\tobjs:\t%d\n",
> > total_moved,
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> > > index d9ab97eabda9..f91d4fcf80b8 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> > > @@ -276,6 +276,9 @@ struct amdgpu_vm {
> > > /* per VM BOs moved, but not yet updated in the PT */
> > > struct list_head moved;
> > >
> > > + /* normal and per VM BOs that are not moved, but have new
> > PT entries */
> > > + struct list_head dirty;
> > > +
> > > /* All BOs of this VM not currently in the state machine */
> > > struct list_head idle;
> > >
> >
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