On Wednesday 17 August 2005 12:43, Stephen Hemminger wrote: > You will get more response to network issues on netdev@xxxxxxxxxxxxxxx Okay. Thanks. > NAPI poll is usually called from softirq context. This means that > hardware interrupts are enabled, but it is not in a thread context that > can sleep. Okay. I wasn't aware of quite how it was "supposed" to be. > You shouldn't be calling things that could sleep! If you are it > is a bug. I guess I'd better track down this bug, then :) > Harald Welte is working on a generic virtual Ethernet device, perhaps > you could collaborate with him. I assume he is on this mailing list? > The bug is that ipv6 is doing an operation to handle MIB statistics and > the MIPS architecture math routines seem to need to sleep. > Previous versions of SNMP code may have done atomic operations, but > current 2.6 code uses per-cpu variables. > Also, there is no might sleep in the current 2.6 MIPS code either > so the problem is probably fixed if you use current 2.6.12 or later > kernel. Hm -- I am using 2.6.13-rc2. Here is a new trace, showing the same issue with IPv4: Debug: sleeping function called from invalid context at arch/mips/math-emu/dsemul.c:137 in_atomic():1, irqs_disabled():0 Call Trace: [<ffffffff801406e0>] __might_sleep+0x180/0x198 (kernel/sched.c:5223) [<ffffffff80101930>] mipsIRQ+0x130/0x1e0 (arch/mips/sc1000/mipsIRQ.S:95) [<ffffffff802860fc>] ip_rcv+0x9c/0x7b0 (net/ipv4/ip_input.c:381) [<ffffffff80140428>] do_dsemulret+0x68/0x1a0 (arch/mips/math-emu/dsemul.c:137) [<ffffffff8010b3a4>] do_ade+0x24/0x550 (arch/mips/kernel/unaligned.c:506) [<ffffffff80102964>] handle_adel_int+0x3c/0x58 (arch/mips/kernel/genex.S:281) [<ffffffff80268260>] netif_receive_skb+0x1b0/0x2e0 (net/core/dev.c:1646) [<ffffffff80286100>] ip_rcv+0xa0/0x7b0 (net/ipv4/ip_input.c:394) [<ffffffff8014da5c>] printk+0x2c/0x38 (kernel/printk.c:515) [<ffffffff80268260>] netif_receive_skb+0x1b0/0x2e0 (net/core/dev.c:1646) [<ffffffff802573c8>] lanlan_poll+0x3e0/0x440 (drivers/net/lanlan.c:246) etc, etc. CC:'ing to linux-mips for obvious reasons. This seems to stem from an unaligned access. If this is no longer appropriate for linux-kernel, feel free to stop CCing to there, and I will follow. Thanks, joshua
