On Fri, Nov 29, 2019 at 11:48 AM Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > > On 2019-11-12 17:42:42 [-0500], Paul Thomas wrote: > > Any thoughts would be appreciated. > > Could please enable CONFIG_DEBUG_ATOMIC_SLEEP and check if the kernel > complains? Hi Sebastian, Well, it does complain (report below), but I'm not sure it's related. The other thing I tried was the AF_XDP example here: https://github.com/xdp-project/xdp-tutorial/tree/master/advanced03-AF_XDP With this example poll() always seems to block correctly, so I think maybe there is something wrong with the xdpsock_user.c example or how I'm using it. [ 259.591480] BUG: assuming atomic context at net/core/ptp_classifier.c:106 [ 259.591488] in_atomic(): 0, irqs_disabled(): 0, pid: 953, name: irq/22-eth%d [ 259.591494] CPU: 0 PID: 953 Comm: irq/22-eth%d Tainted: G WC 5. 2.21-rt13-00016-g93898e751d0e #90 [ 259.591499] Hardware name: Enclustra XU5 SOM (DT) [ 259.591501] Call trace: [ 259.591503] dump_backtrace (/arch/arm64/kernel/traps.c:94) [ 259.591514] show_stack (/arch/arm64/kernel/traps.c:151) [ 259.591520] dump_stack (/lib/dump_stack.c:115) [ 259.591526] __cant_sleep (/kernel/sched/core.c:6386) [ 259.591531] ptp_classify_raw (/./include/linux/compiler.h:194 /./include/asm-generic/atomic-instrumented.h:27 /./include/linux/jump_label.h:251 /net/core/ptp_classifier.c:106) [ 259.591537] skb_defer_rx_timestamp (/./include/linux/skbuff.h:2236 /net/core/timestamping.c:60) [ 259.591541] netif_receive_skb_internal (/net/core/dev.c:5217) [ 259.591547] netif_receive_skb (/net/core/dev.c:5296) [ 259.591550] gem_rx (/drivers/net/ethernet/cadence/macb_main.c:993) [ 259.591556] macb_poll (/drivers/net/ethernet/cadence/macb_main.c:1265) [ 259.591561] net_rx_action (/net/core/dev.c:6387 /net/core/dev.c:6461) [ 259.591565] __do_softirq (/./include/linux/compiler.h:194 /./arch/arm64/include/asm/preempt.h:12 /kernel/softirq.c:400) [ 259.591569] __local_bh_enable_ip (/kernel/softirq.c:182) [ 259.591574] irq_forced_thread_fn (/kernel/irq/manage.c:1008) [ 259.591579] irq_thread (/kernel/irq/manage.c:1101) [ 259.591584] kthread (/kernel/kthread.c:255) [ 259.591589] ret_from_fork (/arch/arm64/kernel/entry.S:1176)