[Intel-gfx] [PATCH 2/2] drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutex
Chris Wilson
chris at chris-wilson.co.uk
Thu Jan 30 09:22:39 UTC 2020
On Braswell and Broxton (also known as Valleyview and Apollolake), we
need to serialise updates of the GGTT using the big stop_machine()
hammer. This has the side effect of appearing to lockdep as a possible
reclaim (since it uses the cpuhp mutex and that is tainted by per-cpu
allocations). However, we want to use vm->mutex (including ggtt->mutex)
from wthin the shrinker and so must avoid such possible taints. For this
purpose, we introduced the asynchronous vma binding and we can apply it
to the PIN_GLOBAL so long as take care to add the necessary waits for
the worker afterwards.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/211
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 7 ++---
drivers/gpu/drm/i915/gt/intel_ggtt.c | 1 +
drivers/gpu/drm/i915/gt/intel_gt.c | 2 +-
drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +-
drivers/gpu/drm/i915/gt/intel_ring.c | 6 ++--
drivers/gpu/drm/i915/gt/intel_timeline.c | 4 +--
drivers/gpu/drm/i915/gt/uc/intel_guc.c | 4 +--
drivers/gpu/drm/i915/i915_active.c | 10 ++++--
drivers/gpu/drm/i915/i915_active.h | 3 +-
drivers/gpu/drm/i915/i915_gem.c | 6 ++++
drivers/gpu/drm/i915/i915_vma.c | 38 +++++++++++++++++++++--
drivers/gpu/drm/i915/i915_vma.h | 2 ++
12 files changed, 65 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 8707d7264490..449bf7770300 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -527,7 +527,6 @@ static int pin_ggtt_status_page(struct intel_engine_cs *engine,
{
unsigned int flags;
- flags = PIN_GLOBAL;
if (!HAS_LLC(engine->i915) && i915_ggtt_has_aperture(engine->gt->ggtt))
/*
* On g33, we cannot place HWS above 256MiB, so
@@ -540,11 +539,11 @@ static int pin_ggtt_status_page(struct intel_engine_cs *engine,
* above the mappable region (even though we never
* actually map it).
*/
- flags |= PIN_MAPPABLE;
+ flags = PIN_MAPPABLE;
else
- flags |= PIN_HIGH;
+ flags = PIN_HIGH;
- return i915_vma_pin(vma, 0, 0, flags);
+ return i915_ggtt_pin(vma, 0, flags);
}
static int init_status_page(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index 81a63f7bc6c4..34211ca85531 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -854,6 +854,7 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt)
IS_CHERRYVIEW(i915) /* fails with concurrent use/update */) {
ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
ggtt->vm.insert_page = bxt_vtd_ggtt_insert_page__BKL;
+ ggtt->vm.bind_async_flags = I915_VMA_GLOBAL_BIND;
}
ggtt->invalidate = gen8_ggtt_invalidate;
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index 143268083135..bf6c0f949e35 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -345,7 +345,7 @@ static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
goto err_unref;
}
- ret = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+ ret = i915_ggtt_pin(vma, 0, PIN_HIGH);
if (ret)
goto err_unref;
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 9a0d0282f3ca..5906fc7df2a4 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3263,7 +3263,7 @@ static int lrc_setup_wa_ctx(struct intel_engine_cs *engine)
goto err;
}
- err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+ err = i915_ggtt_pin(vma, 0, PIN_HIGH);
if (err)
goto err;
diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c
index 374b28f13ca0..366013367526 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring.c
@@ -31,17 +31,15 @@ int intel_ring_pin(struct intel_ring *ring)
if (atomic_fetch_inc(&ring->pin_count))
return 0;
- flags = PIN_GLOBAL;
-
/* Ring wraparound at offset 0 sometimes hangs. No idea why. */
- flags |= PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
+ flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
if (vma->obj->stolen)
flags |= PIN_MAPPABLE;
else
flags |= PIN_HIGH;
- ret = i915_vma_pin(vma, 0, 0, flags);
+ ret = i915_ggtt_pin(vma, 0, flags);
if (unlikely(ret))
goto err_unpin;
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 87716529cd2f..465f87b65901 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -308,7 +308,7 @@ int intel_timeline_pin(struct intel_timeline *tl)
if (atomic_add_unless(&tl->pin_count, 1, 0))
return 0;
- err = i915_vma_pin(tl->hwsp_ggtt, 0, 0, PIN_GLOBAL | PIN_HIGH);
+ err = i915_ggtt_pin(tl->hwsp_ggtt, 0, PIN_HIGH);
if (err)
return err;
@@ -431,7 +431,7 @@ __intel_timeline_get_seqno(struct intel_timeline *tl,
goto err_rollback;
}
- err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+ err = i915_ggtt_pin(vma, 0, PIN_HIGH);
if (err) {
__idle_hwsp_free(vma->private, cacheline);
goto err_rollback;
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
index 5d00a3b2d914..c4c1523da7a6 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
@@ -678,8 +678,8 @@ struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
if (IS_ERR(vma))
goto err;
- flags = PIN_GLOBAL | PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
- ret = i915_vma_pin(vma, 0, 0, flags);
+ flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
+ ret = i915_ggtt_pin(vma, 0, flags);
if (ret) {
vma = ERR_PTR(ret);
goto err;
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 3d2e7cf55e52..da58e5d084f4 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -390,13 +390,19 @@ int i915_active_ref(struct i915_active *ref,
return err;
}
-void i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
+struct dma_fence *
+i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
{
+ struct dma_fence *prev;
+
/* We expect the caller to manage the exclusive timeline ordering */
GEM_BUG_ON(i915_active_is_idle(ref));
- if (!__i915_active_fence_set(&ref->excl, f))
+ prev = __i915_active_fence_set(&ref->excl, f);
+ if (!prev)
atomic_inc(&ref->count);
+
+ return prev;
}
bool i915_active_acquire_if_busy(struct i915_active *ref)
diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
index 51e1e854ca55..973ff0447c6c 100644
--- a/drivers/gpu/drm/i915/i915_active.h
+++ b/drivers/gpu/drm/i915/i915_active.h
@@ -173,7 +173,8 @@ i915_active_add_request(struct i915_active *ref, struct i915_request *rq)
return i915_active_ref(ref, i915_request_timeline(rq), &rq->fence);
}
-void i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f);
+struct dma_fence *
+i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f);
static inline bool i915_active_has_exclusive(struct i915_active *ref)
{
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ff79da5657f8..dda1a0365f39 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1009,6 +1009,12 @@ i915_gem_object_ggtt_pin(struct drm_i915_gem_object *obj,
if (ret)
return ERR_PTR(ret);
+ ret = i915_vma_wait_for_bind(vma);
+ if (ret) {
+ i915_vma_unpin(vma);
+ return ERR_PTR(ret);
+ }
+
return vma;
}
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 84e03da0d5f9..f5dc84e3fef8 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -294,6 +294,7 @@ struct i915_vma_work {
struct dma_fence_work base;
struct i915_vma *vma;
struct drm_i915_gem_object *pinned;
+ struct i915_sw_dma_fence_cb cb;
enum i915_cache_level cache_level;
unsigned int flags;
};
@@ -339,6 +340,25 @@ struct i915_vma_work *i915_vma_work(void)
return vw;
}
+int i915_vma_wait_for_bind(struct i915_vma *vma)
+{
+ int err = 0;
+
+ if (rcu_access_pointer(vma->active.excl.fence)) {
+ struct dma_fence *fence;
+
+ rcu_read_lock();
+ fence = dma_fence_get_rcu_safe(&vma->active.excl.fence);
+ rcu_read_unlock();
+ if (fence) {
+ err = dma_fence_wait(fence, MAX_SCHEDULE_TIMEOUT);
+ dma_fence_put(fence);
+ }
+ }
+
+ return err;
+}
+
/**
* i915_vma_bind - Sets up PTEs for an VMA in it's corresponding address space.
* @vma: VMA to map
@@ -386,6 +406,8 @@ int i915_vma_bind(struct i915_vma *vma,
trace_i915_vma_bind(vma, bind_flags);
if (work && (bind_flags & ~vma_flags) & vma->vm->bind_async_flags) {
+ struct dma_fence *prev;
+
work->vma = vma;
work->cache_level = cache_level;
work->flags = bind_flags | I915_VMA_ALLOC;
@@ -399,8 +421,12 @@ int i915_vma_bind(struct i915_vma *vma,
* part of the obj->resv->excl_fence as it only affects
* execution and not content or object's backing store lifetime.
*/
- GEM_BUG_ON(i915_active_has_exclusive(&vma->active));
- i915_active_set_exclusive(&vma->active, &work->base.dma);
+ prev = i915_active_set_exclusive(&vma->active, &work->base.dma);
+ if (prev)
+ __i915_sw_fence_await_dma_fence(&work->base.chain,
+ prev,
+ &work->cb);
+
work->base.dma.error = 0; /* enable the queue_work() */
if (vma->obj) {
@@ -977,8 +1003,14 @@ int i915_ggtt_pin(struct i915_vma *vma, u32 align, unsigned int flags)
do {
err = i915_vma_pin(vma, 0, align, flags | PIN_GLOBAL);
- if (err != -ENOSPC)
+ if (err != -ENOSPC) {
+ if (!err) {
+ err = i915_vma_wait_for_bind(vma);
+ if (err)
+ i915_vma_unpin(vma);
+ }
return err;
+ }
/* Unlike i915_vma_pin, we don't take no for an answer! */
flush_idle_contexts(vm->gt);
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 02b31a62951e..e1ced1df13e1 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -375,6 +375,8 @@ struct i915_vma *i915_vma_make_unshrinkable(struct i915_vma *vma);
void i915_vma_make_shrinkable(struct i915_vma *vma);
void i915_vma_make_purgeable(struct i915_vma *vma);
+int i915_vma_wait_for_bind(struct i915_vma *vma);
+
static inline int i915_vma_sync(struct i915_vma *vma)
{
/* Wait for the asynchronous bindings and pending GPU reads */
--
2.25.0
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