2017-03-01 15:05:52

by Gerd Hoffmann

Subject: [PATCH] drm: virtio: use kmem_cache

Just use kmem_cache instead of rolling
our own, limited implementation.

Signed-off-by: Gerd Hoffmann <[email protected]>
---
drivers/gpu/drm/virtio/virtgpu_drv.h | 4 +--
drivers/gpu/drm/virtio/virtgpu_vq.c | 57 +++++++-----------------------------
2 files changed, 11 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 2f76673..4e66e35 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -178,9 +178,7 @@ struct virtio_gpu_device {

struct virtio_gpu_queue ctrlq;
struct virtio_gpu_queue cursorq;
- struct list_head free_vbufs;
- spinlock_t free_vbufs_lock;
- void *vbufs;
+ struct kmem_cache *vbufs;
bool vqs_ready;

struct idr resource_idr;
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 43ea0dc..472e349 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -74,51 +74,19 @@ void virtio_gpu_cursor_ack(struct virtqueue *vq)

int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev)
{
- struct virtio_gpu_vbuffer *vbuf;
- int i, size, count = 16;
- void *ptr;
-
- INIT_LIST_HEAD(&vgdev->free_vbufs);
- spin_lock_init(&vgdev->free_vbufs_lock);
- count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
- count += virtqueue_get_vring_size(vgdev->cursorq.vq);
- size = count * VBUFFER_SIZE;
- DRM_INFO("virtio vbuffers: %d bufs, %zdB each, %dkB total.\n",
- count, VBUFFER_SIZE, size / 1024);
-
- vgdev->vbufs = kzalloc(size, GFP_KERNEL);
+ vgdev->vbufs = kmem_cache_create("virtio-gpu-vbufs",
+ VBUFFER_SIZE,
+ __alignof__(struct virtio_gpu_vbuffer),
+ 0, NULL);
if (!vgdev->vbufs)
return -ENOMEM;
-
- for (i = 0, ptr = vgdev->vbufs;
- i < count;
- i++, ptr += VBUFFER_SIZE) {
- vbuf = ptr;
- list_add(&vbuf->list, &vgdev->free_vbufs);
- }
return 0;
}

void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
{
- struct virtio_gpu_vbuffer *vbuf;
- int i, count = 0;
-
- count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
- count += virtqueue_get_vring_size(vgdev->cursorq.vq);
-
- spin_lock(&vgdev->free_vbufs_lock);
- for (i = 0; i < count; i++) {
- if (WARN_ON(list_empty(&vgdev->free_vbufs))) {
- spin_unlock(&vgdev->free_vbufs_lock);
- return;
- }
- vbuf = list_first_entry(&vgdev->free_vbufs,
- struct virtio_gpu_vbuffer, list);
- list_del(&vbuf->list);
- }
- spin_unlock(&vgdev->free_vbufs_lock);
- kfree(vgdev->vbufs);
+ kmem_cache_destroy(vgdev->vbufs);
+ vgdev->vbufs = NULL;
}

static struct virtio_gpu_vbuffer*
@@ -128,12 +96,9 @@ void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
{
struct virtio_gpu_vbuffer *vbuf;

- spin_lock(&vgdev->free_vbufs_lock);
- BUG_ON(list_empty(&vgdev->free_vbufs));
- vbuf = list_first_entry(&vgdev->free_vbufs,
- struct virtio_gpu_vbuffer, list);
- list_del(&vbuf->list);
- spin_unlock(&vgdev->free_vbufs_lock);
+ vbuf = kmem_cache_alloc(vgdev->vbufs, GFP_KERNEL);
+ if (IS_ERR(vbuf))
+ return ERR_CAST(vbuf);
memset(vbuf, 0, VBUFFER_SIZE);

BUG_ON(size > MAX_INLINE_CMD_SIZE);
@@ -208,9 +173,7 @@ static void free_vbuf(struct virtio_gpu_device *vgdev,
if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
kfree(vbuf->resp_buf);
kfree(vbuf->data_buf);
- spin_lock(&vgdev->free_vbufs_lock);
- list_add(&vbuf->list, &vgdev->free_vbufs);
- spin_unlock(&vgdev->free_vbufs_lock);
+ kmem_cache_free(vgdev->vbufs, vbuf);
}

static void reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)
--
1.8.3.1

2017-03-01 15:10:00

by Daniel Vetter

Subject: Re: [PATCH] drm: virtio: use kmem_cache

On Wed, Mar 01, 2017 at 03:09:08PM +0100, Gerd Hoffmann wrote:
> Just use kmem_cache instead of rolling
> our own, limited implementation.
>
> Signed-off-by: Gerd Hoffmann <[email protected]>

Looks very reasonable.

Reviewed-by: Daniel Vetter <[email protected]>

> ---
> drivers/gpu/drm/virtio/virtgpu_drv.h | 4 +--
> drivers/gpu/drm/virtio/virtgpu_vq.c | 57 +++++++-----------------------------
> 2 files changed, 11 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
> index 2f76673..4e66e35 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> @@ -178,9 +178,7 @@ struct virtio_gpu_device {
>
> struct virtio_gpu_queue ctrlq;
> struct virtio_gpu_queue cursorq;
> - struct list_head free_vbufs;
> - spinlock_t free_vbufs_lock;
> - void *vbufs;
> + struct kmem_cache *vbufs;
> bool vqs_ready;
>
> struct idr resource_idr;
> diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
> index 43ea0dc..472e349 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_vq.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
> @@ -74,51 +74,19 @@ void virtio_gpu_cursor_ack(struct virtqueue *vq)
>
> int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev)
> {
> - struct virtio_gpu_vbuffer *vbuf;
> - int i, size, count = 16;
> - void *ptr;
> -
> - INIT_LIST_HEAD(&vgdev->free_vbufs);
> - spin_lock_init(&vgdev->free_vbufs_lock);
> - count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
> - count += virtqueue_get_vring_size(vgdev->cursorq.vq);
> - size = count * VBUFFER_SIZE;
> - DRM_INFO("virtio vbuffers: %d bufs, %zdB each, %dkB total.\n",
> - count, VBUFFER_SIZE, size / 1024);
> -
> - vgdev->vbufs = kzalloc(size, GFP_KERNEL);
> + vgdev->vbufs = kmem_cache_create("virtio-gpu-vbufs",
> + VBUFFER_SIZE,
> + __alignof__(struct virtio_gpu_vbuffer),
> + 0, NULL);
> if (!vgdev->vbufs)
> return -ENOMEM;
> -
> - for (i = 0, ptr = vgdev->vbufs;
> - i < count;
> - i++, ptr += VBUFFER_SIZE) {
> - vbuf = ptr;
> - list_add(&vbuf->list, &vgdev->free_vbufs);
> - }
> return 0;
> }
>
> void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
> {
> - struct virtio_gpu_vbuffer *vbuf;
> - int i, count = 0;
> -
> - count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
> - count += virtqueue_get_vring_size(vgdev->cursorq.vq);
> -
> - spin_lock(&vgdev->free_vbufs_lock);
> - for (i = 0; i < count; i++) {
> - if (WARN_ON(list_empty(&vgdev->free_vbufs))) {
> - spin_unlock(&vgdev->free_vbufs_lock);
> - return;
> - }
> - vbuf = list_first_entry(&vgdev->free_vbufs,
> - struct virtio_gpu_vbuffer, list);
> - list_del(&vbuf->list);
> - }
> - spin_unlock(&vgdev->free_vbufs_lock);
> - kfree(vgdev->vbufs);
> + kmem_cache_destroy(vgdev->vbufs);
> + vgdev->vbufs = NULL;
> }
>
> static struct virtio_gpu_vbuffer*
> @@ -128,12 +96,9 @@ void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
> {
> struct virtio_gpu_vbuffer *vbuf;
>
> - spin_lock(&vgdev->free_vbufs_lock);
> - BUG_ON(list_empty(&vgdev->free_vbufs));
> - vbuf = list_first_entry(&vgdev->free_vbufs,
> - struct virtio_gpu_vbuffer, list);
> - list_del(&vbuf->list);
> - spin_unlock(&vgdev->free_vbufs_lock);
> + vbuf = kmem_cache_alloc(vgdev->vbufs, GFP_KERNEL);
> + if (IS_ERR(vbuf))
> + return ERR_CAST(vbuf);
> memset(vbuf, 0, VBUFFER_SIZE);
>
> BUG_ON(size > MAX_INLINE_CMD_SIZE);
> @@ -208,9 +173,7 @@ static void free_vbuf(struct virtio_gpu_device *vgdev,
> if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
> kfree(vbuf->resp_buf);
> kfree(vbuf->data_buf);
> - spin_lock(&vgdev->free_vbufs_lock);
> - list_add(&vbuf->list, &vgdev->free_vbufs);
> - spin_unlock(&vgdev->free_vbufs_lock);
> + kmem_cache_free(vgdev->vbufs, vbuf);
> }
>
> static void reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)
> --
> 1.8.3.1
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2017-03-10 18:12:39

by Jiri Slaby

Subject: Re: [PATCH] drm: virtio: use kmem_cache

On 03/01/2017, 03:09 PM, Gerd Hoffmann wrote:
> @@ -128,12 +96,9 @@ void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
> {
> struct virtio_gpu_vbuffer *vbuf;
>
> - spin_lock(&vgdev->free_vbufs_lock);
> - BUG_ON(list_empty(&vgdev->free_vbufs));
> - vbuf = list_first_entry(&vgdev->free_vbufs,
> - struct virtio_gpu_vbuffer, list);
> - list_del(&vbuf->list);
> - spin_unlock(&vgdev->free_vbufs_lock);
> + vbuf = kmem_cache_alloc(vgdev->vbufs, GFP_KERNEL);
> + if (IS_ERR(vbuf))
> + return ERR_CAST(vbuf);

AFAICS kmem_cache_alloc returns NULL on error.

> memset(vbuf, 0, VBUFFER_SIZE);
>
> BUG_ON(size > MAX_INLINE_CMD_SIZE);
> @@ -208,9 +173,7 @@ static void free_vbuf(struct virtio_gpu_device *vgdev,
> if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
> kfree(vbuf->resp_buf);
> kfree(vbuf->data_buf);
> - spin_lock(&vgdev->free_vbufs_lock);
> - list_add(&vbuf->list, &vgdev->free_vbufs);
> - spin_unlock(&vgdev->free_vbufs_lock);
> + kmem_cache_free(vgdev->vbufs, vbuf);
> }
>
> static void reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)
>

regards,
--
js
suse labs