| Message ID | 1654229435-2934-1-git-send-email-chen45464546@163.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev_alloc_frag | expand |
On Fri, 3 Jun 2022 12:10:35 +0800 Chen Lin wrote: > - ring->data[i] = netdev_alloc_frag(ring->frag_size); > + if (ring->frag_size <= PAGE_SIZE) > + ring->data[i] = netdev_alloc_frag(ring->frag_size); > + else > + ring->data[i] = kmalloc(ring->frag_size, GFP_KERNEL); Is it legal to allocate pages with kmalloc()? I mean they will end up getting freed by page_frag_free(), not kfree(). Also there's more frag allocations here, search for napi_alloc_frag().
On 03.06.22 06:10, Chen Lin wrote: > When rx_flag == MTK_RX_FLAGS_HWLRO, > rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE. > netdev_alloc_frag is for alloction of page fragment only. > Reference to other drivers and Documentation/vm/page_frags.rst > > Branch to use kmalloc when rx_data_len > PAGE_SIZE. > > Signed-off-by: Chen Lin <chen45464546@163.com> > --- > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > index b3b3c07..d0eebca 100644 > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > @@ -1914,7 +1914,10 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag) > return -ENOMEM; > > for (i = 0; i < rx_dma_size; i++) { > - ring->data[i] = netdev_alloc_frag(ring->frag_size); > + if (ring->frag_size <= PAGE_SIZE) > + ring->data[i] = netdev_alloc_frag(ring->frag_size); > + else > + ring->data[i] = kmalloc(ring->frag_size, GFP_KERNEL); I'm pretty sure you also need to update all the other places in the code that currently assume that the buffer is allocated using the page frag allocator. - Felix
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index b3b3c07..d0eebca 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -1914,7 +1914,10 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag) return -ENOMEM; for (i = 0; i < rx_dma_size; i++) { - ring->data[i] = netdev_alloc_frag(ring->frag_size); + if (ring->frag_size <= PAGE_SIZE) + ring->data[i] = netdev_alloc_frag(ring->frag_size); + else + ring->data[i] = kmalloc(ring->frag_size, GFP_KERNEL); if (!ring->data[i]) return -ENOMEM; }
When rx_flag == MTK_RX_FLAGS_HWLRO, rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE. netdev_alloc_frag is for alloction of page fragment only. Reference to other drivers and Documentation/vm/page_frags.rst Branch to use kmalloc when rx_data_len > PAGE_SIZE. Signed-off-by: Chen Lin <chen45464546@163.com> --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)