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[2/4] drm/ttm: add bit flag TTM_OPT_FLAG_FORCE_ALLOC

Message ID 1518080761-12952-2-git-send-email-Hongbo.He@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

He, Hongbo Feb. 8, 2018, 9:05 a.m. UTC
set TTM_OPT_FLAG_FORCE_ALLOC when we are servicing for page
fault routine.

for ttm_mem_global_reserve if in page fault routine, allow the gtt
pages reservation always. because page fault routing already grabbed
system memory and the allowance of this exception is harmless.
Otherwise, it will trigger OOM killer.

the subsequent patche will use this.

v2: keep original behavior except ttm bo with flag no_retry

Signed-off-by: Roger He <Hongbo.He@amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c          | 6 ++++--
 drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 1 -
 include/drm/ttm/ttm_bo_api.h             | 4 +++-
 3 files changed, 7 insertions(+), 4 deletions(-)

Comments

Christian König Feb. 8, 2018, 12:57 p.m. UTC | #1
Am 08.02.2018 um 10:05 schrieb Roger He:
> set TTM_OPT_FLAG_FORCE_ALLOC when we are servicing for page
> fault routine.
>
> for ttm_mem_global_reserve if in page fault routine, allow the gtt
> pages reservation always. because page fault routing already grabbed
> system memory and the allowance of this exception is harmless.
> Otherwise, it will trigger OOM killer.
>
> the subsequent patche will use this.
>
> v2: keep original behavior except ttm bo with flag no_retry
>
> Signed-off-by: Roger He <Hongbo.He@amd.com>
> ---
>   drivers/gpu/drm/ttm/ttm_bo_vm.c          | 6 ++++--
>   drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 1 -
>   include/drm/ttm/ttm_bo_api.h             | 4 +++-
>   3 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index 716e724..f10b8a0 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -224,7 +224,7 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>   		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
>   						cvma.vm_page_prot);
>   	} else {
> -		struct ttm_operation_ctx ctx = {
> +		struct ttm_operation_ctx ttm_opt_ctx = {
>   			.interruptible = false,
>   			.no_wait_gpu = false
>   		};
> @@ -233,8 +233,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>   		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
>   						cvma.vm_page_prot);
>   
> +		if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
> +			ttm_opt_ctx.flags |= TTM_OPT_FLAG_FORCE_ALLOC;

Can't we always set the TTM_OPT_FLAG_FORCE_ALLOC flag here?

I don't see a reason why we should ever not set it.

Christian.

>   		/* Allocate all page at once, most common usage */
> -		if (ttm->bdev->driver->ttm_tt_populate(ttm, &ctx)) {
> +		if (ttm->bdev->driver->ttm_tt_populate(ttm, &ttm_opt_ctx)) {
>   			ret = VM_FAULT_OOM;
>   			goto out_io_unlock;
>   		}
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> index b122f6e..354e0e1 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> @@ -944,7 +944,6 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
>   	i = 0;
>   
>   	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
> -
>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>   	if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
>   		goto skip_huge;
> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
> index 872ff6c..2142639 100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -278,7 +278,9 @@ struct ttm_operation_ctx {
>   };
>   
>   /* Allow eviction of reserved BOs */
> -#define TTM_OPT_FLAG_ALLOW_RES_EVICT	0x1
> +#define TTM_OPT_FLAG_ALLOW_RES_EVICT		0x1
> +/* when serving page fault or suspend, allow alloc anyway */
> +#define TTM_OPT_FLAG_FORCE_ALLOC		0x2
>   
>   /**
>    * ttm_bo_reference - reference a struct ttm_buffer_object
diff mbox

Patch

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 716e724..f10b8a0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -224,7 +224,7 @@  static int ttm_bo_vm_fault(struct vm_fault *vmf)
 		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 						cvma.vm_page_prot);
 	} else {
-		struct ttm_operation_ctx ctx = {
+		struct ttm_operation_ctx ttm_opt_ctx = {
 			.interruptible = false,
 			.no_wait_gpu = false
 		};
@@ -233,8 +233,10 @@  static int ttm_bo_vm_fault(struct vm_fault *vmf)
 		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 						cvma.vm_page_prot);
 
+		if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
+			ttm_opt_ctx.flags |= TTM_OPT_FLAG_FORCE_ALLOC;
 		/* Allocate all page at once, most common usage */
-		if (ttm->bdev->driver->ttm_tt_populate(ttm, &ctx)) {
+		if (ttm->bdev->driver->ttm_tt_populate(ttm, &ttm_opt_ctx)) {
 			ret = VM_FAULT_OOM;
 			goto out_io_unlock;
 		}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index b122f6e..354e0e1 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -944,7 +944,6 @@  int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
 	i = 0;
 
 	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
-
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 		goto skip_huge;
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 872ff6c..2142639 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -278,7 +278,9 @@  struct ttm_operation_ctx {
 };
 
 /* Allow eviction of reserved BOs */
-#define TTM_OPT_FLAG_ALLOW_RES_EVICT	0x1
+#define TTM_OPT_FLAG_ALLOW_RES_EVICT		0x1
+/* when serving page fault or suspend, allow alloc anyway */
+#define TTM_OPT_FLAG_FORCE_ALLOC		0x2
 
 /**
  * ttm_bo_reference - reference a struct ttm_buffer_object