Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will
use indirect descriptors and allocate them using a simple
kmalloc().
This patch adds a cache which will allow indirect buffers under
a configurable size to be allocated from that cache instead.
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
Changes in v2:
- Free correctly indirect buffers.
drivers/block/virtio_blk.c | 4 ++++
drivers/char/hw_random/virtio-rng.c | 4 ++++
drivers/char/virtio_console.c | 4 ++++
drivers/net/virtio_net.c | 4 ++++
drivers/virtio/virtio_balloon.c | 4 ++++
drivers/virtio/virtio_ring.c | 28 ++++++++++++++++++++++++----
include/linux/virtio.h | 1 +
net/9p/trans_virtio.c | 5 +++++
8 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 13b8ae9..7f670af 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -25,6 +25,9 @@ struct workqueue_struct *virtblk_wq;
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_blk
{
struct virtio_device *vdev;
@@ -739,6 +742,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
vblk->config_enable = true;
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
err = init_vq(vblk);
if (err)
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 02d8421..8475ece 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -28,6 +28,9 @@
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
static struct virtqueue *vq;
static unsigned int data_avail;
static DECLARE_COMPLETION(have_data);
@@ -97,6 +100,7 @@ static int probe_common(struct virtio_device *vdev)
/* We expect a single virtqueue. */
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
vq = virtio_find_single_vq(vdev, random_recv_done, "input");
if (IS_ERR(vq))
return PTR_ERR(vq);
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index fc14e7f..c6f24a7 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -42,6 +42,9 @@
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
@@ -1891,6 +1894,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
&portdev->config.max_nr_ports) == 0)
multiport = true;
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
err = init_vqs(portdev);
if (err < 0) {
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 64a8321..c091efd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -37,6 +37,9 @@ module_param(gso, bool, 0444);
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128
@@ -1132,6 +1135,7 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
err = init_vqs(vi);
if (err)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index fce7347..ccf87db 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -38,6 +38,9 @@
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_balloon
{
struct virtio_device *vdev;
@@ -360,6 +363,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
vb->vdev = vdev;
vb->need_stats_update = 0;
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
err = init_vqs(vb);
if (err)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 99a64a7..e8b9c54 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -93,6 +93,10 @@ struct vring_virtqueue
*/
unsigned int indirect_thresh;
+ /* Buffers below this size will be allocated from cache */
+ unsigned int indirect_alloc_thresh;
+ struct kmem_cache *indirect_cache;
+
/* Host publishes avail event idx */
bool event;
@@ -135,7 +139,10 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
unsigned head;
int i;
- desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp);
+ if ((out + in) <= vq->indirect_alloc_thresh)
+ desc = kmem_cache_alloc(vq->indirect_cache, gfp);
+ else
+ desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp);
if (!desc)
return -ENOMEM;
@@ -384,8 +391,13 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
i = head;
/* Free the indirect table */
- if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT)
- kfree(phys_to_virt(vq->vring.desc[i].addr));
+ if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT) {
+ if (vq->vring.desc[i].len > vq->indirect_alloc_thresh)
+ kfree(phys_to_virt(vq->vring.desc[i].addr));
+ else
+ kmem_cache_free(vq->indirect_cache,
+ phys_to_virt(vq->vring.desc[i].addr));
+ }
while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
i = vq->vring.desc[i].next;
@@ -654,14 +666,20 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
vq->last_used_idx = 0;
vq->num_added = 0;
vq->indirect_thresh = 0;
+ vq->indirect_alloc_thresh = 0;
+ vq->indirect_cache = NULL;
list_add_tail(&vq->vq.list, &vdev->vqs);
#ifdef DEBUG
vq->in_use = false;
vq->last_add_time_valid = false;
#endif
- if (virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
+ if (virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
vq->indirect_thresh = vdev->indirect_thresh;
+ vq->indirect_alloc_thresh = vdev->indirect_alloc_thresh;
+ if (vq->indirect_alloc_thresh)
+ vq->indirect_cache = KMEM_CACHE(vring_desc[vq->indirect_alloc_thresh], 0);
+ }
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
@@ -685,6 +703,8 @@ EXPORT_SYMBOL_GPL(vring_new_virtqueue);
void vring_del_virtqueue(struct virtqueue *vq)
{
list_del(&vq->list);
+ if (to_vvq(vq)->indirect_cache)
+ kmem_cache_destroy(to_vvq(vq)->indirect_cache);
kfree(to_vvq(vq));
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 48bc457..3261c02 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -70,6 +70,7 @@ struct virtio_device {
unsigned long features[1];
void *priv;
unsigned int indirect_thresh;
+ unsigned int indirect_alloc_thresh;
};
#define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index fc93962..3044c86 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -55,6 +55,9 @@
static unsigned int indirect_thresh;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
/* a single mutex to manage channel initialization and attachment */
static DEFINE_MUTEX(virtio_9p_lock);
static DECLARE_WAIT_QUEUE_HEAD(vp_wq);
@@ -505,6 +508,8 @@ static int p9_virtio_probe(struct virtio_device *vdev)
/* We expect one virtqueue, for requests. */
vdev->indirect_thresh = indirect_thresh;
+ vdev->indirect_alloc_thresh = indirect_alloc_thresh;
+
chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
if (IS_ERR(chan->vq)) {
err = PTR_ERR(chan->vq);
--
1.7.12
--
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