gitops/mt76
1
0
Fork 0
mirror of https://github.com/outbackdingo/mt76.git synced 2026-10-24 13:26:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

mt76: use a per rx queue page fragment cache

Browse Source 
Using the NAPI or netdev frag cache along with other drivers can lead to
32 KiB pages being held for a long time, despite only being used for
very few page fragments.

This can happen if the driver grabs one or two fragments for rx ring
refill, while other drivers use (and free up) the remaining fragments.
The 32 KiB higher-order page can only be freed once all users have freed
their fragments.

Depending on the traffic patterns, this can waste a lot of memory and
look a lot like a memory leak.

Signed-off-by: Felix Fietkau <[email protected]>
This commit is contained in:
Felix Fietkau
2018-09-12 13:16:50 +02:00
parent 2b3b4df596
commit 39a380a06c
3 changed files with 20 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files
usb.c
+10 -1
View File
@@ -275,6 +275,7 @@ static int
mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76u_buf *buf,
int nsgs, int len, int sglen)
{
struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
struct urb *urb = buf->urb;
int i;
@@ -283,7 +284,7 @@ mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76u_buf *buf,
void *data;
int offset;
data = netdev_alloc_frag(len);
data = page_frag_alloc(&q->rx_page, q->buf_size, GFP_ATOMIC);
if (!data)
break;
@@ -550,10 +551,18 @@ static int mt76u_alloc_rx(struct mt76_dev *dev)
static void mt76u_free_rx(struct mt76_dev *dev)
{
struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
struct page *page;
int i;
for (i = 0; i < q->ndesc; i++)
mt76u_buf_free(&q->entry[i].ubuf);
if (!q->rx_page.va)
return;
page = virt_to_page(q->rx_page.va);
__page_frag_cache_drain(page, q->rx_page.pagecnt_bias);
memset(&q->rx_page, 0, sizeof(q->rx_page));
}
static void mt76u_stop_rx(struct mt76_dev *dev)