Messages in this thread |  | | From | Eric Dumazet <> | Date | Fri, 3 Jun 2022 10:25:16 -0700 | Subject | Re: [PATCH v2] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag |
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On Fri, Jun 3, 2022 at 1:46 AM Chen Lin <chen45464546@163.com> 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 alloc_pages when ring->frag_size > PAGE_SIZE. > > Signed-off-by: Chen Lin <chen45464546@163.com>
...
> goto release_desc; > @@ -1914,7 +1923,16 @@ 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);
Note aside, calling netdev_alloc_frag() in a loop like that is adding GFP_ATOMIC pressure.
mtk_rx_alloc() being in process context, using GFP_KERNEL allocations would be less aggressive and have more chances to succeed.
We probably should offer a generic helper. This could be used from driver/net/tun.c and others.
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