* [RFC 1/2] virtio-ring: Use threshold for switching to indirect descriptors
@ 2012-06-18 14:09 Sasha Levin
2012-06-18 14:09 ` [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible Sasha Levin
2012-06-18 14:09 ` Sasha Levin
0 siblings, 2 replies; 6+ messages in thread
From: Sasha Levin @ 2012-06-18 14:09 UTC (permalink / raw)
To: mst, asias, stefanha; +Cc: virtualization, kvm, Sasha Levin
Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect
descriptors even if we have plenty of space in the ring. This means that
we take a performance hit at all times due to the overhead of creating
indirect descriptors.
Instead, use it only after we're below a configurable offset.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
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 | 21 +++++++++++++++------
include/linux/virtio.h | 1 +
net/9p/trans_virtio.c | 4 ++++
8 files changed, 40 insertions(+), 6 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 693187d..a2c8d97 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -19,6 +19,9 @@ static DEFINE_IDA(vd_index_ida);
struct workqueue_struct *virtblk_wq;
+static unsigned int indirect_thresh = 0;
+module_param(indirect_thresh, uint, S_IRUGO);
+
struct virtio_blk
{
spinlock_t lock;
@@ -438,6 +441,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
mutex_init(&vblk->config_lock);
INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
vblk->config_enable = true;
+ vdev->indirect_thresh = indirect_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 723725b..bcaddb9 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -25,6 +25,9 @@
#include <linux/virtio_rng.h>
#include <linux/module.h>
+static unsigned int indirect_thresh = 0;
+module_param(indirect_thresh, uint, S_IRUGO);
+
static struct virtqueue *vq;
static unsigned int data_avail;
static DECLARE_COMPLETION(have_data);
@@ -90,6 +93,7 @@ static int virtrng_probe(struct virtio_device *vdev)
int err;
/* We expect a single virtqueue. */
+ vdev->indirect_thresh = indirect_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 cdf2f54..60397a4 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -37,6 +37,9 @@
#include <linux/module.h>
#include "../tty/hvc/hvc_console.h"
+static unsigned int indirect_thresh = 0;
+module_param(indirect_thresh, uint, S_IRUGO);
+
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
@@ -1729,6 +1732,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
max_nr_ports),
&portdev->config.max_nr_ports) == 0)
multiport = true;
+ vdev->indirect_thresh = indirect_thresh;
err = init_vqs(portdev);
if (err < 0) {
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f18149a..5c1be92 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -34,6 +34,9 @@ static bool csum = true, gso = true;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);
+static unsigned int indirect_thresh = 0;
+module_param(indirect_thresh, uint, S_IRUGO);
+
/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128
@@ -1128,6 +1131,7 @@ 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;
err = init_vqs(vi);
if (err)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index bfbc15c..4fc11ba 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -35,6 +35,9 @@
*/
#define VIRTIO_BALLOON_PAGES_PER_PAGE (PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT)
+static unsigned int indirect_thresh = 0;
+module_param(indirect_thresh, uint, S_IRUGO);
+
struct virtio_balloon
{
struct virtio_device *vdev;
@@ -360,6 +363,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
init_waitqueue_head(&vb->config_change);
vb->vdev = vdev;
vb->need_stats_update = 0;
+ vdev->indirect_thresh = indirect_thresh;
err = init_vqs(vb);
if (err)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5aa43c3..99a64a7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -87,8 +87,11 @@ struct vring_virtqueue
/* Other side has made a mess, don't try any more. */
bool broken;
- /* Host supports indirect buffers */
- bool indirect;
+ /*
+ * Min. number of free space in the ring to trigger direct
+ * descriptor use
+ */
+ unsigned int indirect_thresh;
/* Host publishes avail event idx */
bool event;
@@ -216,9 +219,12 @@ int virtqueue_add_buf(struct virtqueue *_vq,
}
#endif
- /* If the host supports indirect descriptor tables, and we have multiple
- * buffers, then go indirect. FIXME: tune this threshold */
- if (vq->indirect && (out + in) > 1 && vq->num_free) {
+ /*
+ * If the host supports indirect descriptor tables, and we have multiple
+ * buffers, then go indirect.
+ */
+ if ((out + in) > 1 && vq->num_free &&
+ (vq->num_free < vq->indirect_thresh)) {
head = vring_add_indirect(vq, sg, out, in, gfp);
if (likely(head >= 0))
goto add_head;
@@ -647,13 +653,16 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
vq->broken = false;
vq->last_used_idx = 0;
vq->num_added = 0;
+ vq->indirect_thresh = 0;
list_add_tail(&vq->vq.list, &vdev->vqs);
#ifdef DEBUG
vq->in_use = false;
vq->last_add_time_valid = false;
#endif
- vq->indirect = 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->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
/* No callback? Tell other side not to bother us. */
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 8efd28a..36019ec 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -69,6 +69,7 @@ struct virtio_device {
/* Note that this is a Linux set_bit-style bitmap. */
unsigned long features[1];
void *priv;
+ unsigned int indirect_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 5af18d1..357bfba 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -52,6 +52,9 @@
#define VIRTQUEUE_NUM 128
+static unsigned int indirect_thresh = 0;
+module_param(indirect_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);
@@ -501,6 +504,7 @@ static int p9_virtio_probe(struct virtio_device *vdev)
chan->vdev = vdev;
/* We expect one virtqueue, for requests. */
+ vdev->indirect_thresh = indirect_thresh;
chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
if (IS_ERR(chan->vq)) {
err = PTR_ERR(chan->vq);
--
1.7.8.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible
2012-06-18 14:09 [RFC 1/2] virtio-ring: Use threshold for switching to indirect descriptors Sasha Levin
@ 2012-06-18 14:09 ` Sasha Levin
2012-06-19 5:51 ` Jean-Mickael Guerin
2012-06-19 5:51 ` Jean-Mickael Guerin
2012-06-18 14:09 ` Sasha Levin
1 sibling, 2 replies; 6+ messages in thread
From: Sasha Levin @ 2012-06-18 14:09 UTC (permalink / raw)
To: mst, asias, stefanha; +Cc: virtualization, kvm, Sasha Levin
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@gmail.com>
---
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 a2c8d97..3c6d1bd 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -22,6 +22,9 @@ struct workqueue_struct *virtblk_wq;
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_blk
{
spinlock_t lock;
@@ -442,6 +445,7 @@ 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 bcaddb9..6a32f76 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 = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
static struct virtqueue *vq;
static unsigned int data_avail;
static DECLARE_COMPLETION(have_data);
@@ -94,6 +97,7 @@ static int virtrng_probe(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 60397a4..7c33714 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -40,6 +40,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
@@ -1733,6 +1736,7 @@ 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 5c1be92..441bd2f 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 = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+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 4fc11ba..6e6313b 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -38,6 +38,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_balloon
{
struct virtio_device *vdev;
@@ -364,6 +367,7 @@ 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..f0b0ce3 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 36019ec..f3f0d3f 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 357bfba..8424b36 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -55,6 +55,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+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);
--
1.7.8.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible
2012-06-18 14:09 [RFC 1/2] virtio-ring: Use threshold for switching to indirect descriptors Sasha Levin
2012-06-18 14:09 ` [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible Sasha Levin
@ 2012-06-18 14:09 ` Sasha Levin
1 sibling, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2012-06-18 14:09 UTC (permalink / raw)
To: mst, asias, stefanha; +Cc: Sasha Levin, kvm, virtualization
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@gmail.com>
---
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 a2c8d97..3c6d1bd 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -22,6 +22,9 @@ struct workqueue_struct *virtblk_wq;
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_blk
{
spinlock_t lock;
@@ -442,6 +445,7 @@ 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 bcaddb9..6a32f76 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 = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
static struct virtqueue *vq;
static unsigned int data_avail;
static DECLARE_COMPLETION(have_data);
@@ -94,6 +97,7 @@ static int virtrng_probe(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 60397a4..7c33714 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -40,6 +40,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
@@ -1733,6 +1736,7 @@ 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 5c1be92..441bd2f 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 = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+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 4fc11ba..6e6313b 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -38,6 +38,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+module_param(indirect_alloc_thresh, uint, S_IRUGO);
+
struct virtio_balloon
{
struct virtio_device *vdev;
@@ -364,6 +367,7 @@ 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..f0b0ce3 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 36019ec..f3f0d3f 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 357bfba..8424b36 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -55,6 +55,9 @@
static unsigned int indirect_thresh = 0;
module_param(indirect_thresh, uint, S_IRUGO);
+static unsigned int indirect_alloc_thresh = 0;
+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);
--
1.7.8.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible
2012-06-18 14:09 ` [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible Sasha Levin
2012-06-19 5:51 ` Jean-Mickael Guerin
@ 2012-06-19 5:51 ` Jean-Mickael Guerin
2012-08-28 12:54 ` Sasha Levin
1 sibling, 1 reply; 6+ messages in thread
From: Jean-Mickael Guerin @ 2012-06-19 5:51 UTC (permalink / raw)
To: Sasha Levin; +Cc: mst, asias, stefanha, kvm, virtualization
On 18/06/2012 16:09, Sasha Levin wrote:
> 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@gmail.com>
> ---
> 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 a2c8d97..3c6d1bd 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -22,6 +22,9 @@ struct workqueue_struct *virtblk_wq;
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> struct virtio_blk
> {
> spinlock_t lock;
> @@ -442,6 +445,7 @@ 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 bcaddb9..6a32f76 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 = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> static struct virtqueue *vq;
> static unsigned int data_avail;
> static DECLARE_COMPLETION(have_data);
> @@ -94,6 +97,7 @@ static int virtrng_probe(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 60397a4..7c33714 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -40,6 +40,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> /*
> * This is a global struct for storing common data for all the devices
> * this driver handles.
> @@ -1733,6 +1736,7 @@ 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 5c1be92..441bd2f 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 = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +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 4fc11ba..6e6313b 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -38,6 +38,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> struct virtio_balloon
> {
> struct virtio_device *vdev;
> @@ -364,6 +367,7 @@ 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..f0b0ce3 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)
This should be > instead of <, no?
>
> + 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 36019ec..f3f0d3f 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 357bfba..8424b36 100644
> --- a/net/9p/trans_virtio.c
> +++ b/net/9p/trans_virtio.c
> @@ -55,6 +55,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +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);
Jean-Mickael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible
2012-06-18 14:09 ` [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible Sasha Levin
@ 2012-06-19 5:51 ` Jean-Mickael Guerin
2012-06-19 5:51 ` Jean-Mickael Guerin
1 sibling, 0 replies; 6+ messages in thread
From: Jean-Mickael Guerin @ 2012-06-19 5:51 UTC (permalink / raw)
To: Sasha Levin; +Cc: virtualization, kvm, mst
On 18/06/2012 16:09, Sasha Levin wrote:
> 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@gmail.com>
> ---
> 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 a2c8d97..3c6d1bd 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -22,6 +22,9 @@ struct workqueue_struct *virtblk_wq;
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> struct virtio_blk
> {
> spinlock_t lock;
> @@ -442,6 +445,7 @@ 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 bcaddb9..6a32f76 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 = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> static struct virtqueue *vq;
> static unsigned int data_avail;
> static DECLARE_COMPLETION(have_data);
> @@ -94,6 +97,7 @@ static int virtrng_probe(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 60397a4..7c33714 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -40,6 +40,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> /*
> * This is a global struct for storing common data for all the devices
> * this driver handles.
> @@ -1733,6 +1736,7 @@ 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 5c1be92..441bd2f 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 = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +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 4fc11ba..6e6313b 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -38,6 +38,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +module_param(indirect_alloc_thresh, uint, S_IRUGO);
> +
> struct virtio_balloon
> {
> struct virtio_device *vdev;
> @@ -364,6 +367,7 @@ 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..f0b0ce3 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)
This should be > instead of <, no?
>
> + 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 36019ec..f3f0d3f 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 357bfba..8424b36 100644
> --- a/net/9p/trans_virtio.c
> +++ b/net/9p/trans_virtio.c
> @@ -55,6 +55,9 @@
> static unsigned int indirect_thresh = 0;
> module_param(indirect_thresh, uint, S_IRUGO);
>
> +static unsigned int indirect_alloc_thresh = 0;
> +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);
Jean-Mickael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible
2012-06-19 5:51 ` Jean-Mickael Guerin
@ 2012-08-28 12:54 ` Sasha Levin
0 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2012-08-28 12:54 UTC (permalink / raw)
To: Jean-Mickael Guerin; +Cc: virtualization, kvm, mst
On 06/19/2012 07:51 AM, Jean-Mickael Guerin wrote:
>> + if (vq->vring.desc[i].flags& VRING_DESC_F_INDIRECT) {
>> + if (vq->vring.desc[i].len< vq->indirect_alloc_thresh)
> This should be > instead of <, no?
It should, yeah.
Too bad slub doesn't yell at you for doing that.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-08-28 12:54 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-06-18 14:09 [RFC 1/2] virtio-ring: Use threshold for switching to indirect descriptors Sasha Levin
2012-06-18 14:09 ` [RFC 2/2] virtio-ring: Allocate indirect buffers from cache when possible Sasha Levin
2012-06-19 5:51 ` Jean-Mickael Guerin
2012-06-19 5:51 ` Jean-Mickael Guerin
2012-08-28 12:54 ` Sasha Levin
2012-06-18 14:09 ` Sasha Levin
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