linux/drivers/net/ntb_netdev.c

745 lines
16 KiB

net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx() The following is emitted when using idxd (DSA) dmanegine as the data mover for ntb_transport that ntb_netdev uses. [74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526 [74412.556784] caller is netif_rx_internal+0x42/0x130 [74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5 [74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024 [74412.581699] Call Trace: [74412.584514] <TASK> [74412.586933] dump_stack_lvl+0x55/0x70 [74412.591129] check_preemption_disabled+0xc8/0xf0 [74412.596374] netif_rx_internal+0x42/0x130 [74412.600957] __netif_rx+0x20/0xd0 [74412.604743] ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev] [74412.610985] ntb_complete_rxc+0xed/0x140 [ntb_transport] [74412.617010] ntb_rx_copy_callback+0x53/0x80 [ntb_transport] [74412.623332] idxd_dma_complete_txd+0xe3/0x160 [idxd] [74412.628963] idxd_wq_thread+0x1a6/0x2b0 [idxd] [74412.634046] irq_thread_fn+0x21/0x60 [74412.638134] ? irq_thread+0xa8/0x290 [74412.642218] irq_thread+0x1a0/0x290 [74412.646212] ? __pfx_irq_thread_fn+0x10/0x10 [74412.651071] ? __pfx_irq_thread_dtor+0x10/0x10 [74412.656117] ? __pfx_irq_thread+0x10/0x10 [74412.660686] kthread+0x100/0x130 [74412.664384] ? __pfx_kthread+0x10/0x10 [74412.668639] ret_from_fork+0x31/0x50 [74412.672716] ? __pfx_kthread+0x10/0x10 [74412.676978] ret_from_fork_asm+0x1a/0x30 [74412.681457] </TASK> The cause is due to the idxd driver interrupt completion handler uses threaded interrupt and the threaded handler is not hard or soft interrupt context. However __netif_rx() can only be called from interrupt context. Change the call to netif_rx() in order to allow completion via normal context for dmaengine drivers that utilize threaded irq handling. While the following commit changed from netif_rx() to __netif_rx(), baebdf48c360 ("net: dev: Makes sure netif_rx() can be invoked in any context."), the change should've been a noop instead. However, the code precedes this fix should've been using netif_rx_ni() or netif_rx_any_context(). Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device") Reported-by: Jerry Dai <jerry.dai@intel.com> Tested-by: Jerry Dai <jerry.dai@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20240701181538.3799546-1-dave.jiang@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-01 11:15:38 -07:00
ntb_netdev: Use dev_kfree_skb_any() in interrupt context TX/RX callback handlers (ntb_netdev_tx_handler(), ntb_netdev_rx_handler()) can be called in interrupt context via the DMA framework when the respective DMA operations have completed. As such, any calls by these routines to free skb's, should use the interrupt context safe dev_kfree_skb_any() function. Previously, these callback handlers would call the interrupt unsafe version of dev_kfree_skb(). This has not presented an issue on Intel IOAT DMA engines as that driver utilizes tasklets rather than a hard interrupt handler, like the AMD PTDMA DMA driver. On AMD systems, a kernel WARNING message is encountered, which is being issued from skb_release_head_state() due to in_hardirq() being true. Besides the user visible WARNING from the kernel, the other symptom of this bug was that TCP/IP performance across the ntb_netdev interface was very poor, i.e. approximately an order of magnitude below what was expected. With the repair to use dev_kfree_skb_any(), kernel WARNINGs from skb_release_head_state() ceased and TCP/IP performance, as measured by iperf, was on par with expected results, approximately 20 Gb/s on AMD Milan based server. Note that this performance is comparable with Intel based servers. Fixes: 765ccc7bc3d91 ("ntb_netdev: correct skb leak") Fixes: 548c237c0a997 ("net: Add support for NTB virtual ethernet device") Signed-off-by: Eric Pilmore <epilmore@gigaio.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20221209000659.8318-1-epilmore@gigaio.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-08 16:06:59 -08:00
ntb_netdev: Use dev_kfree_skb_any() in interrupt context TX/RX callback handlers (ntb_netdev_tx_handler(), ntb_netdev_rx_handler()) can be called in interrupt context via the DMA framework when the respective DMA operations have completed. As such, any calls by these routines to free skb's, should use the interrupt context safe dev_kfree_skb_any() function. Previously, these callback handlers would call the interrupt unsafe version of dev_kfree_skb(). This has not presented an issue on Intel IOAT DMA engines as that driver utilizes tasklets rather than a hard interrupt handler, like the AMD PTDMA DMA driver. On AMD systems, a kernel WARNING message is encountered, which is being issued from skb_release_head_state() due to in_hardirq() being true. Besides the user visible WARNING from the kernel, the other symptom of this bug was that TCP/IP performance across the ntb_netdev interface was very poor, i.e. approximately an order of magnitude below what was expected. With the repair to use dev_kfree_skb_any(), kernel WARNINGs from skb_release_head_state() ceased and TCP/IP performance, as measured by iperf, was on par with expected results, approximately 20 Gb/s on AMD Milan based server. Note that this performance is comparable with Intel based servers. Fixes: 765ccc7bc3d91 ("ntb_netdev: correct skb leak") Fixes: 548c237c0a997 ("net: Add support for NTB virtual ethernet device") Signed-off-by: Eric Pilmore <epilmore@gigaio.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20221209000659.8318-1-epilmore@gigaio.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-08 16:06:59 -08:00
net: use core MTU range checking in core net infra geneve: - Merge __geneve_change_mtu back into geneve_change_mtu, set max_mtu - This one isn't quite as straight-forward as others, could use some closer inspection and testing macvlan: - set min/max_mtu tun: - set min/max_mtu, remove tun_net_change_mtu vxlan: - Merge __vxlan_change_mtu back into vxlan_change_mtu - Set max_mtu to IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function - This one is also not as straight-forward and could use closer inspection and testing from vxlan folks bridge: - set max_mtu of IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function openvswitch: - set min/max_mtu, remove internal_dev_change_mtu - note: max_mtu wasn't checked previously, it's been set to 65535, which is the largest possible size supported sch_teql: - set min/max_mtu (note: max_mtu previously unchecked, used max of 65535) macsec: - min_mtu = 0, max_mtu = 65535 macvlan: - min_mtu = 0, max_mtu = 65535 ntb_netdev: - min_mtu = 0, max_mtu = 65535 veth: - min_mtu = 68, max_mtu = 65535 8021q: - min_mtu = 0, max_mtu = 65535 CC: netdev@vger.kernel.org CC: Nicolas Dichtel <nicolas.dichtel@6wind.com> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> CC: Tom Herbert <tom@herbertland.com> CC: Daniel Borkmann <daniel@iogearbox.net> CC: Alexander Duyck <alexander.h.duyck@intel.com> CC: Paolo Abeni <pabeni@redhat.com> CC: Jiri Benc <jbenc@redhat.com> CC: WANG Cong <xiyou.wangcong@gmail.com> CC: Roopa Prabhu <roopa@cumulusnetworks.com> CC: Pravin B Shelar <pshelar@ovn.org> CC: Sabrina Dubroca <sd@queasysnail.net> CC: Patrick McHardy <kaber@trash.net> CC: Stephen Hemminger <stephen@networkplumber.org> CC: Pravin Shelar <pshelar@nicira.com> CC: Maxim Krasnyansky <maxk@qti.qualcomm.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20 13:55:20 -04:00