For rq, we have three cases getting buffers from virtio core:
1. virtqueue_get_buf{,_ctx}
2. virtqueue_detach_unused_buf
3. callback for virtqueue_resize
But in commit 295525e29a5b("virtio_net: merge dma operations when
filling mergeable buffers"), I missed the dma unmap for the #3 case.
That will leak some memory, because I did not release the pages referred
by the unused buffers.
If we do such script, we will make the system OOM.
while true
do
ethtool -G ens4 rx 128
ethtool -G ens4 rx 256
free -m
done
Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling
mergeable buffers")
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/net/virtio_net.c | 43 ++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d16f592c2061..6423a3a007ce 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -408,6 +408,17 @@ static struct page *get_a_page(struct receive_queue *rq,
gfp_t gfp_mask)
return p;
}
+static void virtnet_rq_free_buf(struct virtnet_info *vi,
+ struct receive_queue *rq, void *buf)
+{
+ if (vi->mergeable_rx_bufs)
+ put_page(virt_to_head_page(buf));
+ else if (vi->big_packets)
+ give_pages(rq, buf);
+ else
+ put_page(virt_to_head_page(buf));
+}
+
static void enable_delayed_refill(struct virtnet_info *vi)
{
spin_lock_bh(&vi->refill_lock);
@@ -634,17 +645,6 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq,
u32 *len, void **ctx)
return buf;
}
-static void *virtnet_rq_detach_unused_buf(struct receive_queue *rq)
-{
- void *buf;
-
- buf = virtqueue_detach_unused_buf(rq->vq);
- if (buf && rq->do_dma)
- virtnet_rq_unmap(rq, buf, 0);
-
- return buf;
-}
-
static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32
len)
{
struct virtnet_rq_dma *dma;
@@ -1764,7 +1764,7 @@ static void receive_buf(struct virtnet_info *vi, struct
receive_queue *rq,
if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
pr_debug("%s: short packet %i\n", dev->name, len);
DEV_STATS_INC(dev, rx_length_errors);
- virtnet_rq_free_unused_buf(rq->vq, buf);
+ virtnet_rq_free_buf(vi, rq, buf);
return;
}
@@ -4034,14 +4034,15 @@ static void virtnet_sq_free_unused_buf(struct virtqueue
*vq, void *buf)
static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
{
struct virtnet_info *vi = vq->vdev->priv;
+ struct receive_queue *rq;
int i = vq2rxq(vq);
- if (vi->mergeable_rx_bufs)
- put_page(virt_to_head_page(buf));
- else if (vi->big_packets)
- give_pages(&vi->rq[i], buf);
- else
- put_page(virt_to_head_page(buf));
+ rq = &vi->rq[i];
+
+ if (rq->do_dma)
+ virtnet_rq_unmap(rq, buf, 0);
+
+ virtnet_rq_free_buf(vi, rq, buf);
}
static void free_unused_bufs(struct virtnet_info *vi)
@@ -4057,10 +4058,10 @@ static void free_unused_bufs(struct virtnet_info *vi)
}
for (i = 0; i < vi->max_queue_pairs; i++) {
- struct receive_queue *rq = &vi->rq[i];
+ struct virtqueue *vq = vi->rq[i].vq;
- while ((buf = virtnet_rq_detach_unused_buf(rq)) != NULL)
- virtnet_rq_free_unused_buf(rq->vq, buf);
+ while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
+ virtnet_rq_free_unused_buf(vq, buf);
cond_resched();
}
}
--
2.32.0.3.g01195cf9f