Messages in this thread |  | | Date | Fri, 3 Jun 2022 11:59:56 -0700 | From | Jakub Kicinski <> | 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, 3 Jun 2022 10:25:16 -0700 Eric Dumazet wrote: > > 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.
Do cases where netdev_alloc_frag() is not run from a process context from to your mind? My feeling is that the prevailing pattern is what this driver does, which is netdev_alloc_frag() at startup / open and napi_alloc_frag() from the datapath. So maybe we can even spare the detail in the API and have napi_alloc_frag() assume GFP_KERNEL by default?
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