[PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible
STALE5092d
From: Sasha Levin <hidden>
Date: 2012-08-28 13:04:00
Also in:
kvm, lkml
Subsystem:
9p file system, block layer, char and misc drivers, hardware random number generator core, networking drivers, the rest, virtio balloon, virtio block and scsi drivers, virtio console driver, virtio core, virtio net driver, virtio rng driver · Maintainers:
Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet, Jens Axboe, Arnd Bergmann, Greg Kroah-Hartman, Olivia Mackall, Herbert Xu, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", David Hildenbrand, Jason Wang, Amit Shah, Eugenio Pérez, Laurent Vivier
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 <redacted> --- 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