leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drm/i915: Allow contexts to be unreferenced locklessly

Browse Source 
If we move the actual cleanup of the context to a worker, we can allow
the final free to be called from any context and avoid undue latency in
the caller.

v2: Negotiate handling the delayed contexts free by flushing the
workqueue before calling i915_gem_context_fini() and performing the final
free of the kernel context directly
v3: Flush deferred frees before new context allocations

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170620110547.15947-2-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2017-06-20 12:05:46 +01:00
parent 829a0af29f
commit 5f09a9c8ab
10 changed files with 88 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/i915/gvt/scheduler.c
View File

@ -620,7 +620,7 @@ err:
void intel_vgpu_clean_gvt_context(struct intel_vgpu *vgpu)
{
i915_gem_context_put_unlocked(vgpu->shadow_ctx);
i915_gem_context_put(vgpu->shadow_ctx);
}
int intel_vgpu_init_gvt_context(struct intel_vgpu *vgpu)

2
drivers/gpu/drm/i915/i915_drv.c
View File

@ -585,6 +585,8 @@ static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
static void i915_gem_fini(struct drm_i915_private *dev_priv)
{
flush_workqueue(dev_priv->wq);
mutex_lock(&dev_priv->drm.struct_mutex);
intel_uc_fini_hw(dev_priv);
i915_gem_cleanup_engines(dev_priv);

23
drivers/gpu/drm/i915/i915_drv.h
View File

@ -2315,6 +2315,8 @@ struct drm_i915_private {
struct {
struct list_head list;
struct llist_head free_list;
struct work_struct free_work;
/* The hw wants to have a stable context identifier for the
* lifetime of the context (for OA, PASID, faults, etc).
@ -3545,27 +3547,6 @@ i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id)
return ctx;
}
static inline struct i915_gem_context *
i915_gem_context_get(struct i915_gem_context *ctx)
{
kref_get(&ctx->ref);
return ctx;
}
static inline void i915_gem_context_put(struct i915_gem_context *ctx)
{
lockdep_assert_held(&ctx->i915->drm.struct_mutex);
kref_put(&ctx->ref, i915_gem_context_free);
}
static inline void i915_gem_context_put_unlocked(struct i915_gem_context *ctx)
{
struct mutex *lock = &ctx->i915->drm.struct_mutex;
if (kref_put_mutex(&ctx->ref, i915_gem_context_free, lock))
mutex_unlock(lock);
}
static inline struct intel_timeline *
i915_gem_context_lookup_timeline(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)

59
drivers/gpu/drm/i915/i915_gem_context.c
View File

@ -158,13 +158,11 @@ static void vma_lut_free(struct i915_gem_context *ctx)
kvfree(lut->ht);
}
void i915_gem_context_free(struct kref *ctx_ref)
static void i915_gem_context_free(struct i915_gem_context *ctx)
{
struct i915_gem_context *ctx = container_of(ctx_ref, typeof(*ctx), ref);
int i;
lockdep_assert_held(&ctx->i915->drm.struct_mutex);
trace_i915_context_free(ctx);
GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
vma_lut_free(ctx);
@ -192,6 +190,37 @@ void i915_gem_context_free(struct kref *ctx_ref)
kfree(ctx);
}
static void contexts_free(struct drm_i915_private *i915)
{
struct llist_node *freed = llist_del_all(&i915->contexts.free_list);
struct i915_gem_context *ctx;
lockdep_assert_held(&i915->drm.struct_mutex);
llist_for_each_entry(ctx, freed, free_link)
i915_gem_context_free(ctx);
}
static void contexts_free_worker(struct work_struct *work)
{
struct drm_i915_private *i915 =
container_of(work, typeof(*i915), contexts.free_work);
mutex_lock(&i915->drm.struct_mutex);
contexts_free(i915);
mutex_unlock(&i915->drm.struct_mutex);
}
void i915_gem_context_release(struct kref *ref)
{
struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
struct drm_i915_private *i915 = ctx->i915;
trace_i915_context_free(ctx);
if (llist_add(&ctx->free_link, &i915->contexts.free_list))
queue_work(i915->wq, &i915->contexts.free_work);
}
static void context_close(struct i915_gem_context *ctx)
{
i915_gem_context_set_closed(ctx);
@ -428,6 +457,8 @@ int i915_gem_contexts_init(struct drm_i915_private *dev_priv)
return 0;
INIT_LIST_HEAD(&dev_priv->contexts.list);
INIT_WORK(&dev_priv->contexts.free_work, contexts_free_worker);
init_llist_head(&dev_priv->contexts.free_list);
if (intel_vgpu_active(dev_priv) &&
HAS_LOGICAL_RING_CONTEXTS(dev_priv)) {
@ -505,18 +536,20 @@ void i915_gem_contexts_lost(struct drm_i915_private *dev_priv)
}
}
void i915_gem_contexts_fini(struct drm_i915_private *dev_priv)
void i915_gem_contexts_fini(struct drm_i915_private *i915)
{
struct i915_gem_context *dctx = dev_priv->kernel_context;
struct i915_gem_context *ctx;
lockdep_assert_held(&dev_priv->drm.struct_mutex);
lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(!i915_gem_context_is_kernel(dctx));
/* Keep the context so that we can free it immediately ourselves */
ctx = i915_gem_context_get(fetch_and_zero(&i915->kernel_context));
GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
context_close(ctx);
i915_gem_context_free(ctx);
context_close(dctx);
dev_priv->kernel_context = NULL;
ida_destroy(&dev_priv->contexts.hw_ida);
/* Must free all deferred contexts (via flush_workqueue) first */
ida_destroy(&i915->contexts.hw_ida);
}
static int context_idr_cleanup(int id, void *p, void *data)
@ -957,6 +990,10 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
if (ret)
return ret;
/* Reap stale contexts */
i915_gem_retire_requests(dev_priv);
contexts_free(dev_priv);
ctx = i915_gem_create_context(dev_priv, file_priv);
mutex_unlock(&dev->struct_mutex);
if (IS_ERR(ctx))

15
drivers/gpu/drm/i915/i915_gem_context.h
View File

@ -86,6 +86,7 @@ struct i915_gem_context {
/** link: place with &drm_i915_private.context_list */
struct list_head link;
struct llist_node free_link;
/**
* @ref: reference count
@ -284,7 +285,7 @@ void i915_gem_context_close(struct drm_file *file);
int i915_switch_context(struct drm_i915_gem_request *req);
int i915_gem_switch_to_kernel_context(struct drm_i915_private *dev_priv);
void i915_gem_context_free(struct kref *ctx_ref);
void i915_gem_context_release(struct kref *ctx_ref);
struct i915_gem_context *
i915_gem_context_create_gvt(struct drm_device *dev);
@ -299,4 +300,16 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
int i915_gem_context_reset_stats_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
static inline struct i915_gem_context *
i915_gem_context_get(struct i915_gem_context *ctx)
{
kref_get(&ctx->ref);
return ctx;
}
static inline void i915_gem_context_put(struct i915_gem_context *ctx)
{
kref_put(&ctx->ref, i915_gem_context_release);
}
#endif /* !__I915_GEM_CONTEXT_H__ */

4
drivers/gpu/drm/i915/i915_perf.c
View File

@ -2444,7 +2444,7 @@ static void i915_perf_destroy_locked(struct i915_perf_stream *stream)
list_del(&stream->link);
if (stream->ctx)
i915_gem_context_put_unlocked(stream->ctx);
i915_gem_context_put(stream->ctx);
kfree(stream);
}
@ -2633,7 +2633,7 @@ err_alloc:
kfree(stream);
err_ctx:
if (specific_ctx)
i915_gem_context_put_unlocked(specific_ctx);
i915_gem_context_put(specific_ctx);
err:
return ret;
}

8
drivers/gpu/drm/i915/selftests/i915_vma.c
View File

@ -186,16 +186,20 @@ static int igt_vma_create(void *arg)
goto end;
}
list_for_each_entry_safe(ctx, cn, &contexts, link)
list_for_each_entry_safe(ctx, cn, &contexts, link) {
list_del_init(&ctx->link);
mock_context_close(ctx);
}
}
end:
/* Final pass to lookup all created contexts */
err = create_vmas(i915, &objects, &contexts);
out:
list_for_each_entry_safe(ctx, cn, &contexts, link)
list_for_each_entry_safe(ctx, cn, &contexts, link) {
list_del_init(&ctx->link);
mock_context_close(ctx);
}
list_for_each_entry_safe(obj, on, &objects, st_link)
i915_gem_object_put(obj);

9
drivers/gpu/drm/i915/selftests/mock_context.c
View File

@ -86,3 +86,12 @@ void mock_context_close(struct i915_gem_context *ctx)
i915_gem_context_put(ctx);
}
void mock_init_contexts(struct drm_i915_private *i915)
{
INIT_LIST_HEAD(&i915->contexts.list);
ida_init(&i915->contexts.hw_ida);
INIT_WORK(&i915->contexts.free_work, contexts_free_worker);
init_llist_head(&i915->contexts.free_list);
}

2
drivers/gpu/drm/i915/selftests/mock_context.h
View File

@ -25,6 +25,8 @@
#ifndef __MOCK_CONTEXT_H
#define __MOCK_CONTEXT_H
void mock_init_contexts(struct drm_i915_private *i915);
struct i915_gem_context *
mock_context(struct drm_i915_private *i915,
const char *name);

3
drivers/gpu/drm/i915/selftests/mock_gem_device.c
View File

@ -57,6 +57,7 @@ static void mock_device_release(struct drm_device *dev)
cancel_delayed_work_sync(&i915->gt.retire_work);
cancel_delayed_work_sync(&i915->gt.idle_work);
flush_workqueue(i915->wq);
mutex_lock(&i915->drm.struct_mutex);
for_each_engine(engine, i915, id)
@ -160,7 +161,7 @@ struct drm_i915_private *mock_gem_device(void)
INIT_LIST_HEAD(&i915->mm.unbound_list);
INIT_LIST_HEAD(&i915->mm.bound_list);
ida_init(&i915->contexts.hw_ida);
mock_init_contexts(i915);
INIT_DELAYED_WORK(&i915->gt.retire_work, mock_retire_work_handler);
INIT_DELAYED_WORK(&i915->gt.idle_work, mock_idle_work_handler);