From: Daniel Phillips <Daniel.Phillips@xxxxxxx> Add a new KFD ioctl to return the largest possible memory size that can be allocated as a buffer object using kfd_ioctl_alloc_memory_of_gpu. It attempts to use exactly the same accept/reject criteria as that function so that allocating a new buffer object of the size returned by this new ioctl is guaranteed to succeed, barring races with other allocating tasks. This IOCTL will be used by libhsakmt: https://www.mail-archive.com/amd-gfx@xxxxxxxxxxxxxxxxxxxxx/msg75743.html Signed-off-by: Daniel Phillips <Daniel.Phillips@xxxxxxx> Signed-off-by: David Yat Sin <david.yatsin@xxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 + .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 37 +++++++++++++++++-- drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 34 +++++++++++++++++ include/uapi/linux/kfd_ioctl.h | 14 ++++++- 4 files changed, 80 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index f8b9f27adcf5..0b0ab1de76ca 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -266,6 +266,7 @@ int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct amdgpu_device *adev, void amdgpu_amdkfd_gpuvm_release_process_vm(struct amdgpu_device *adev, void *drm_priv); uint64_t amdgpu_amdkfd_gpuvm_get_process_page_dir(void *drm_priv); +size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev); int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu( struct amdgpu_device *adev, uint64_t va, uint64_t size, void *drm_priv, struct kgd_mem **mem, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 34ba9e776521..105af82d41a4 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -38,6 +38,12 @@ */ #define AMDGPU_USERPTR_RESTORE_DELAY_MS 1 +/* + * Align VRAM allocations to 2MB to avoid fragmentation caused by 4K allocations in the tail 2MB + * BO chunk + */ +#define VRAM_ALLOCATION_ALIGN (1 << 21) + /* Impose limit on how much memory KFD can use */ static struct { uint64_t max_system_mem_limit; @@ -108,7 +114,7 @@ void amdgpu_amdkfd_reserve_system_mem(uint64_t size) * compromise that should work in most cases without reserving too * much memory for page tables unnecessarily (factor 16K, >> 14). */ -#define ESTIMATE_PT_SIZE(mem_size) ((mem_size) >> 14) +#define ESTIMATE_PT_SIZE(mem_size) max(((mem_size) >> 14), AMDGPU_VM_RESERVED_VRAM) static size_t amdgpu_amdkfd_acc_size(uint64_t size) { @@ -148,7 +154,12 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev, } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) { system_mem_needed = acc_size; ttm_mem_needed = acc_size; - vram_needed = size; + + /* + * Conservatively round up the allocation requirement to 2 MB to avoid fragmentation + * caused by 4K allocations in the tail 2M BO chunk + */ + vram_needed = ALIGN(size, VRAM_ALLOCATION_ALIGN); } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) { system_mem_needed = acc_size + size; ttm_mem_needed = acc_size; @@ -173,7 +184,9 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev, (kfd_mem_limit.ttm_mem_used + ttm_mem_needed > kfd_mem_limit.max_ttm_mem_limit) || (adev->kfd.vram_used + vram_needed > - adev->gmc.real_vram_size - reserved_for_pt)) { + adev->gmc.real_vram_size - + atomic64_read(&adev->vram_pin_size) - + reserved_for_pt)) { ret = -ENOMEM; goto release; } @@ -205,7 +218,7 @@ static void unreserve_mem_limit(struct amdgpu_device *adev, } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) { kfd_mem_limit.system_mem_used -= acc_size; kfd_mem_limit.ttm_mem_used -= acc_size; - adev->kfd.vram_used -= size; + adev->kfd.vram_used -= ALIGN(size, VRAM_ALLOCATION_ALIGN); } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) { kfd_mem_limit.system_mem_used -= (acc_size + size); kfd_mem_limit.ttm_mem_used -= acc_size; @@ -1492,6 +1505,22 @@ int amdgpu_amdkfd_criu_resume(void *p) return ret; } +size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev) +{ + uint64_t reserved_for_pt = + ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size); + size_t available; + + spin_lock(&kfd_mem_limit.mem_limit_lock); + available = adev->gmc.real_vram_size + - adev->kfd.vram_used + - atomic64_read(&adev->vram_pin_size) + - reserved_for_pt; + spin_unlock(&kfd_mem_limit.mem_limit_lock); + + return ALIGN_DOWN(available, VRAM_ALLOCATION_ALIGN); +} + int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu( struct amdgpu_device *adev, uint64_t va, uint64_t size, void *drm_priv, struct kgd_mem **mem, diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 95fa7a9718bb..625e837f0119 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -65,6 +65,25 @@ static int kfd_char_dev_major = -1; static struct class *kfd_class; struct device *kfd_device; +static inline struct kfd_process_device *kfd_lock_pdd_by_id(struct kfd_process *p, __u32 gpu_id) +{ + struct kfd_process_device *pdd; + + mutex_lock(&p->mutex); + pdd = kfd_process_device_data_by_id(p, gpu_id); + + if (pdd) + return pdd; + + mutex_unlock(&p->mutex); + return NULL; +} + +static inline void kfd_unlock_pdd(struct kfd_process_device *pdd) +{ + mutex_unlock(&pdd->process->mutex); +} + int kfd_chardev_init(void) { int err = 0; @@ -958,6 +977,19 @@ bool kfd_dev_is_large_bar(struct kfd_dev *dev) return false; } +static int kfd_ioctl_get_available_memory(struct file *filep, + struct kfd_process *p, void *data) +{ + struct kfd_ioctl_get_available_memory_args *args = data; + struct kfd_process_device *pdd = kfd_lock_pdd_by_id(p, args->gpu_id); + + if (!pdd) + return -EINVAL; + args->available = amdgpu_amdkfd_get_available_memory(pdd->dev->adev); + kfd_unlock_pdd(pdd); + return 0; +} + static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep, struct kfd_process *p, void *data) { @@ -2642,6 +2674,8 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = { AMDKFD_IOCTL_DEF(AMDKFD_IOC_CRIU_OP, kfd_ioctl_criu, KFD_IOC_FLAG_CHECKPOINT_RESTORE), + AMDKFD_IOCTL_DEF(AMDKFD_IOC_AVAILABLE_MEMORY, + kfd_ioctl_get_available_memory, 0), }; #define AMDKFD_CORE_IOCTL_COUNT ARRAY_SIZE(amdkfd_ioctls) diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h index eb9ff85f8556..c648ed7c5ff1 100644 --- a/include/uapi/linux/kfd_ioctl.h +++ b/include/uapi/linux/kfd_ioctl.h @@ -34,9 +34,10 @@ * - 1.6 - Query clear flags in SVM get_attr API * - 1.7 - Checkpoint Restore (CRIU) API * - 1.8 - CRIU - Support for SDMA transfers with GTT BOs + * - 1.9 - Add available memory ioctl */ #define KFD_IOCTL_MAJOR_VERSION 1 -#define KFD_IOCTL_MINOR_VERSION 8 +#define KFD_IOCTL_MINOR_VERSION 9 struct kfd_ioctl_get_version_args { __u32 major_version; /* from KFD */ @@ -100,6 +101,12 @@ struct kfd_ioctl_get_queue_wave_state_args { __u32 pad; }; +struct kfd_ioctl_get_available_memory_args { + __u64 available; /* from KFD */ + __u32 gpu_id; /* to KFD */ + __u32 pad; +}; + /* For kfd_ioctl_set_memory_policy_args.default_policy and alternate_policy */ #define KFD_IOC_CACHE_POLICY_COHERENT 0 #define KFD_IOC_CACHE_POLICY_NONCOHERENT 1 @@ -824,7 +831,10 @@ struct kfd_ioctl_set_xnack_mode_args { #define AMDKFD_IOC_CRIU_OP \ AMDKFD_IOWR(0x22, struct kfd_ioctl_criu_args) +#define AMDKFD_IOC_AVAILABLE_MEMORY \ + AMDKFD_IOWR(0x23, struct kfd_ioctl_get_available_memory_args) + #define AMDKFD_COMMAND_START 0x01 -#define AMDKFD_COMMAND_END 0x23 +#define AMDKFD_COMMAND_END 0x24 #endif -- 2.30.2
