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drm/amdkfd: add svm_bo eviction mechanism support

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svm_bo eviction mechanism is different from regular BOs.
Every SVM_BO created contains one eviction fence and one
worker item for eviction process.
SVM_BOs can be attached to one or more pranges.
For SVM_BO eviction mechanism, TTM will start to call
enable_signal callback for every SVM_BO until VRAM space
is available.
Here, all the ttm_evict calls are synchronous, this guarantees
that each eviction has completed and the fence has signaled before
it returns.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Felix Kuehling 2021-02-24 23:24:53 -05:00 committed by Alex Deucher
parent f04c79cfba
commit b41896e3ee
2 changed files with 168 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

201
drivers/gpu/drm/amd/amdkfd/kfd_svm.c
View File

@ -35,6 +35,7 @@
#define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
static void svm_range_evict_svm_bo_worker(struct work_struct *work);
static bool
svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range,
@ -320,7 +321,15 @@ static void svm_range_bo_release(struct kref *kref)
spin_lock(&svm_bo->list_lock);
}
spin_unlock(&svm_bo->list_lock);
if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
/* We're not in the eviction worker.
* Signal the fence and synchronize with any
* pending eviction work.
*/
dma_fence_signal(&svm_bo->eviction_fence->base);
cancel_work_sync(&svm_bo->eviction_work);
}
dma_fence_put(&svm_bo->eviction_fence->base);
amdgpu_bo_unref(&svm_bo->bo);
kfree(svm_bo);
}
@ -333,6 +342,61 @@ static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
kref_put(&svm_bo->kref, svm_range_bo_release);
}
static bool svm_range_validate_svm_bo(struct svm_range *prange)
{
mutex_lock(&prange->lock);
if (!prange->svm_bo) {
mutex_unlock(&prange->lock);
return false;
}
if (prange->ttm_res) {
/* We still have a reference, all is well */
mutex_unlock(&prange->lock);
return true;
}
if (svm_bo_ref_unless_zero(prange->svm_bo)) {
if (READ_ONCE(prange->svm_bo->evicting)) {
struct dma_fence *f;
struct svm_range_bo *svm_bo;
/* The BO is getting evicted,
* we need to get a new one
*/
mutex_unlock(&prange->lock);
svm_bo = prange->svm_bo;
f = dma_fence_get(&svm_bo->eviction_fence->base);
svm_range_bo_unref(prange->svm_bo);
/* wait for the fence to avoid long spin-loop
* at list_empty_careful
*/
dma_fence_wait(f, false);
dma_fence_put(f);
} else {
/* The BO was still around and we got
* a new reference to it
*/
mutex_unlock(&prange->lock);
pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
prange->svms, prange->start, prange->last);
prange->ttm_res = &prange->svm_bo->bo->tbo.mem;
return true;
}
} else {
mutex_unlock(&prange->lock);
}
/* We need a new svm_bo. Spin-loop to wait for concurrent
* svm_range_bo_release to finish removing this range from
* its range list. After this, it is safe to reuse the
* svm_bo pointer and svm_bo_list head.
*/
while (!list_empty_careful(&prange->svm_bo_list))
;
return false;
}
static struct svm_range_bo *svm_range_bo_new(void)
{
struct svm_range_bo *svm_bo;
@ -352,72 +416,56 @@ int
svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
bool clear)
{
struct amdkfd_process_info *process_info;
struct amdgpu_bo_param bp;
struct svm_range_bo *svm_bo;
struct amdgpu_bo_user *ubo;
struct amdgpu_bo *bo;
struct kfd_process *p;
struct mm_struct *mm;
int r;
pr_debug("[0x%lx 0x%lx]\n", prange->start, prange->last);
mutex_lock(&prange->lock);
if (prange->svm_bo) {
if (prange->ttm_res) {
/* We still have a reference, all is well */
mutex_unlock(&prange->lock);
return 0;
}
if (svm_bo_ref_unless_zero(prange->svm_bo)) {
/* The BO was still around and we got
* a new reference to it
*/
mutex_unlock(&prange->lock);
pr_debug("reuse old bo [0x%lx 0x%lx]\n",
prange->start, prange->last);
p = container_of(prange->svms, struct kfd_process, svms);
pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
prange->start, prange->last);
prange->ttm_res = &prange->svm_bo->bo->tbo.mem;
return 0;
}
mutex_unlock(&prange->lock);
/* We need a new svm_bo. Spin-loop to wait for concurrent
* svm_range_bo_release to finish removing this range from
* its range list. After this, it is safe to reuse the
* svm_bo pointer and svm_bo_list head.
*/
while (!list_empty_careful(&prange->svm_bo_list))
;
} else {
mutex_unlock(&prange->lock);
}
if (svm_range_validate_svm_bo(prange))
return 0;
svm_bo = svm_range_bo_new();
if (!svm_bo) {
pr_debug("failed to alloc svm bo\n");
return -ENOMEM;
}
mm = get_task_mm(p->lead_thread);
if (!mm) {
pr_debug("failed to get mm\n");
kfree(svm_bo);
return -ESRCH;
}
svm_bo->svms = prange->svms;
svm_bo->eviction_fence =
amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
mm,
svm_bo);
mmput(mm);
INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
svm_bo->evicting = 0;
memset(&bp, 0, sizeof(bp));
bp.size = prange->npages * PAGE_SIZE;
bp.byte_align = PAGE_SIZE;
bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
bp.flags |= AMDGPU_AMDKFD_CREATE_SVM_BO;
bp.type = ttm_bo_type_device;
bp.resv = NULL;
r = amdgpu_bo_create_user(adev, &bp, &ubo);
if (r) {
pr_debug("failed %d to create bo\n", r);
kfree(svm_bo);
return r;
goto create_bo_failed;
}
bo = &ubo->bo;
p = container_of(prange->svms, struct kfd_process, svms);
r = amdgpu_bo_reserve(bo, true);
if (r) {
pr_debug("failed %d to reserve bo\n", r);
@ -430,8 +478,7 @@ svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
amdgpu_bo_unreserve(bo);
goto reserve_bo_failed;
}
process_info = p->kgd_process_info;
amdgpu_bo_fence(bo, &process_info->eviction_fence->base, true);
amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
amdgpu_bo_unreserve(bo);
@ -447,8 +494,10 @@ svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
return 0;
reserve_bo_failed:
kfree(svm_bo);
amdgpu_bo_unref(&bo);
create_bo_failed:
dma_fence_put(&svm_bo->eviction_fence->base);
kfree(svm_bo);
prange->ttm_res = NULL;
return r;
@ -2329,6 +2378,74 @@ svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
return r;
}
int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
{
if (!fence)
return -EINVAL;
if (dma_fence_is_signaled(&fence->base))
return 0;
if (fence->svm_bo) {
WRITE_ONCE(fence->svm_bo->evicting, 1);
schedule_work(&fence->svm_bo->eviction_work);
}
return 0;
}
static void svm_range_evict_svm_bo_worker(struct work_struct *work)
{
struct svm_range_bo *svm_bo;
struct kfd_process *p;
struct mm_struct *mm;
svm_bo = container_of(work, struct svm_range_bo, eviction_work);
if (!svm_bo_ref_unless_zero(svm_bo))
return; /* svm_bo was freed while eviction was pending */
/* svm_range_bo_release destroys this worker thread. So during
* the lifetime of this thread, kfd_process and mm will be valid.
*/
p = container_of(svm_bo->svms, struct kfd_process, svms);
mm = p->mm;
if (!mm)
return;
mmap_read_lock(mm);
spin_lock(&svm_bo->list_lock);
while (!list_empty(&svm_bo->range_list)) {
struct svm_range *prange =
list_first_entry(&svm_bo->range_list,
struct svm_range, svm_bo_list);
list_del_init(&prange->svm_bo_list);
spin_unlock(&svm_bo->list_lock);
pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
prange->start, prange->last);
mutex_lock(&prange->migrate_mutex);
svm_migrate_vram_to_ram(prange, svm_bo->eviction_fence->mm);
mutex_lock(&prange->lock);
prange->svm_bo = NULL;
mutex_unlock(&prange->lock);
mutex_unlock(&prange->migrate_mutex);
spin_lock(&svm_bo->list_lock);
}
spin_unlock(&svm_bo->list_lock);
mmap_read_unlock(mm);
dma_fence_signal(&svm_bo->eviction_fence->base);
/* This is the last reference to svm_bo, after svm_range_vram_node_free
* has been called in svm_migrate_vram_to_ram
*/
WARN_ONCE(kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
svm_range_bo_unref(svm_bo);
}
static int
svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)

13
drivers/gpu/drm/amd/amdkfd/kfd_svm.h
View File

@ -34,10 +34,14 @@
#include "kfd_priv.h"
struct svm_range_bo {
struct amdgpu_bo *bo;
struct kref kref;
struct list_head range_list; /* all svm ranges shared this bo */
spinlock_t list_lock;
struct amdgpu_bo *bo;
struct kref kref;
struct list_head range_list; /* all svm ranges shared this bo */
spinlock_t list_lock;
struct amdgpu_amdkfd_fence *eviction_fence;
struct work_struct eviction_work;
struct svm_range_list *svms;
uint32_t evicting;
};
enum svm_work_list_ops {
@ -157,6 +161,7 @@ int svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
struct svm_range *prange);
int svm_range_restore_pages(struct amdgpu_device *adev,
unsigned int pasid, uint64_t addr);
int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence);
void svm_range_add_list_work(struct svm_range_list *svms,
struct svm_range *prange, struct mm_struct *mm,
enum svm_work_list_ops op);