> Hi Yuval, > > [auto build test WARNING on net-next/master] > > url: https://github.com/0day-ci/linux/commits/Yuval-Mintz/qed-Add-XDP- > support/20161127-225956 > config: tile-allmodconfig (attached as .config) > compiler: tilegx-linux-gcc (GCC) 4.6.2 > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp- > tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # save the attached .config to linux build tree > make.cross ARCH=tile > > All warnings (new ones prefixed by >>): > > drivers/net/ethernet/qlogic/qede/qede_main.c: In function > 'qede_alloc_mem_rxq': > >> drivers/net/ethernet/qlogic/qede/qede_main.c:2960:3: warning: large > >> integer implicitly truncated to unsigned type [-Woverflow] > > vim +2960 drivers/net/ethernet/qlogic/qede/qede_main.c > > 55482edc Manish Chopra 2016-03-04 2944 err: > 55482edc Manish Chopra 2016-03-04 2945 qede_free_sge_mem(edev, > rxq); > 55482edc Manish Chopra 2016-03-04 2946 edev->gro_disable = 1; > 55482edc Manish Chopra 2016-03-04 2947 return -ENOMEM; > 55482edc Manish Chopra 2016-03-04 2948 } 55482edc Manish Chopra 2016- > 03-04 2949 > 2950219d Yuval Mintz 2015-10-26 2950 /* This function allocates all > memory needed per Rx queue */ > 1a635e48 Yuval Mintz 2016-08-15 2951 static int > qede_alloc_mem_rxq(struct qede_dev *edev, struct qede_rx_queue *rxq) > 2950219d Yuval Mintz 2015-10-26 2952 { > f86af2df Manish Chopra 2016-04-20 2953 int i, rc, size; > 2950219d Yuval Mintz 2015-10-26 2954 > 2950219d Yuval Mintz 2015-10-26 2955 rxq->num_rx_buffers = edev- > >q_num_rx_buffers; > 2950219d Yuval Mintz 2015-10-26 2956 > 1a635e48 Yuval Mintz 2016-08-15 2957 rxq->rx_buf_size = > NET_IP_ALIGN + ETH_OVERHEAD + edev->ndev->mtu; > 1a635e48 Yuval Mintz 2016-08-15 2958 > fc48b7a6 Yuval Mintz 2016-02-15 2959 if (rxq->rx_buf_size > > PAGE_SIZE) > fc48b7a6 Yuval Mintz 2016-02-15 @2960 rxq->rx_buf_size = > PAGE_SIZE;
I'd say this is a false positive, given that MTU can't be so large. Although patch #10 is going to hit the same when setting rx_buf_seg_size [also a u16] to PAGE_SIZE to make sure there's a single packet per page. While I can surely address that, I was just wondering about whether this is an interesting scenario at the moment. I.e., using XDP with 64 Kb pages is going to be very costly from a memory perspective.
