> -----Original Message----- > From: Eric Dumazet [mailto:eric.duma...@gmail.com] > Sent: Thursday, August 27, 2020 4:26 PM > To: Li,Rongqing <lirongq...@baidu.com>; netdev@vger.kernel.org; > intel-wired-...@lists.osuosl.org > Subject: Re: [PATCH] iavf: use kvzalloc instead of kzalloc for rx/tx_bi buffer > > > > On 8/27/20 12:53 AM, Li RongQing wrote: > > when changes the rx/tx ring to 4096, kzalloc may fail due to a > > temporary shortage on slab entries. > > > > kvmalloc is used to allocate this memory as there is no need to have > > this memory area physical continuously. > > > > Signed-off-by: Li RongQing <lirongq...@baidu.com> > > --- > > > Well, fallback to vmalloc() overhead because order-1 pages are not readily > available when the NIC is setup (usually one time per boot) is adding TLB cost > at run time, for billions of packets to come, maybe for months. > > Surely trying a bit harder to get order-1 pages is desirable. > > __GFP_RETRY_MAYFAIL is supposed to help here.
Could we add __GFP_RETRY_MAYFAIL to kvmalloc, to ensure the allocation success ? > I see that lots of drivers are using vmalloc for this buffer, should we change it kmalloc? grep "buffer_info =" drivers/net/ethernet/intel/ -rI|grep alloc drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: tx_ring->tx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: rx_ring->rx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: tx_ring->tx_buffer_info = vmalloc_node(size, ring_node); drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: tx_ring->tx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: rx_ring->rx_buffer_info = vmalloc_node(size, ring_node); drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: rx_ring->rx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/ixgb/ixgb_main.c: txdr->buffer_info = vzalloc(size); drivers/net/ethernet/intel/ixgb/ixgb_main.c: rxdr->buffer_info = vzalloc(size); drivers/net/ethernet/intel/e1000e/ethtool.c: tx_ring->buffer_info = kcalloc(tx_ring->count, drivers/net/ethernet/intel/e1000e/ethtool.c: rx_ring->buffer_info = kcalloc(rx_ring->count, drivers/net/ethernet/intel/e1000e/netdev.c: tx_ring->buffer_info = vzalloc(size); drivers/net/ethernet/intel/e1000e/netdev.c: rx_ring->buffer_info = vzalloc(size); drivers/net/ethernet/intel/igb/igb_main.c: tx_ring->tx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/igb/igb_main.c: rx_ring->rx_buffer_info = vmalloc(size); drivers/net/ethernet/intel/e1000/e1000_ethtool.c: txdr->buffer_info = kcalloc(txdr->count, sizeof(struct e1000_tx_buffer), drivers/net/ethernet/intel/e1000/e1000_ethtool.c: rxdr->buffer_info = kcalloc(rxdr->count, sizeof(struct e1000_rx_buffer), drivers/net/ethernet/intel/e1000/e1000_main.c: txdr->buffer_info = vzalloc(size); drivers/net/ethernet/intel/e1000/e1000_main.c: rxdr->buffer_info = vzalloc(size); drivers/net/ethernet/intel/igc/igc_main.c: tx_ring->tx_buffer_info = vzalloc(size); drivers/net/ethernet/intel/igc/igc_main.c: rx_ring->rx_buffer_info = vzalloc(size); drivers/net/ethernet/intel/igbvf/netdev.c: tx_ring->buffer_info = vzalloc(size); drivers/net/ethernet/intel/igbvf/netdev.c: rx_ring->buffer_info = vzalloc(size); -Li
