Description of problem: DMA(mapping) failing within SysKonnect Gigabit Ethernet driver - skge. Version-Release number of selected component (if applicable): 3.9.0-0.rc0.git5.1.fc18.x86_64 How reproducible: Engaging the network interface during system startup. Actual results: The only side effect that has been observed is the reduced flow of data. Network interface behaves as 100Mb/s, therefore slower than it should be - 1000Mb/s. Expected results: Speed: 1000Mb/s, that is in practice ~300Mb/s. Additional info: ------------[ cut here ]------------ WARNING: at lib/dma-debug.c:933 check_unmap+0x407/0x8a0() Hardware name: M720-US3 skge 0000:01:09.0: DMA-API: device driver failed to check map error[device address=0x0000000105d52522] [size=90 bytes] [mapped as single] Modules linked in: …rfkill ip6t_REJECT nf_conntrack_ipv6 nf_conntrack_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 xt_conntrack ip6table_filter nf_conntrack ip6_tables… vhost_net tun macvtap… macvlan… nfsd auth_rpcgss nfs_acl lockd… r8169… mii skge… sunrpc… (irrelevant omitted) Pid: 0, comm: swapper/3 Tainted: GF O 3.9.0-0.rc0.git5.1.fc18.x86_64 #1 Call Trace: <IRQ> [<ffffffff81069b5f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff81069c56>] warn_slowpath_fmt+0x46/0x50 [<ffffffff81387a47>] check_unmap+0x407/0x8a0 [<ffffffff810ab62f>] ? try_to_wake_up+0x1ff/0x350 [<ffffffff813880fe>] debug_dma_unmap_page+0x5e/0x70 [<ffffffffa00750ac>] ? skge_intr+0x2c/0x570 [skge] [<ffffffffa0073525>] skge_poll+0x1b5/0x9c0 [skge] [<ffffffff815e7672>] net_rx_action+0x172/0x380 [<ffffffff810737e0>] __do_softirq+0x100/0x400 [<ffffffff81021dd3>] ? native_sched_clock+0x13/0x80 [<ffffffff81739c7c>] call_softirq+0x1c/0x30 [<ffffffff8101c435>] do_softirq+0xa5/0xe0 [<ffffffff81073cd5>] irq_exit+0xd5/0xe0 [<ffffffff8173a5b3>] do_IRQ+0x63/0xe0 [<ffffffff8172f732>] common_interrupt+0x72/0x72 <EOI> [<ffffffff8172f150>] ? _raw_spin_unlock_irq+0x30/0x50 [<ffffffff8172f154>] ? _raw_spin_unlock_irq+0x34/0x50 [<ffffffff8172f150>] ? _raw_spin_unlock_irq+0x30/0x50 [<ffffffff810a3ddc>] finish_task_switch+0x7c/0x120 [<ffffffff810a3d9f>] ? finish_task_switch+0x3f/0x120 [<ffffffff8172cd02>] __schedule+0x442/0xa00 [<ffffffff8172d5f9>] schedule+0x29/0x70 [<ffffffff81023abf>] cpu_idle+0x12f/0x140 [<ffffffff8171a70e>] start_secondary+0x269/0x26b ---[ end trace d41e441560f83f6a ]--- Mapped at: [<ffffffff813881b9>] debug_dma_map_page+0xa9/0x150 [<ffffffffa0074c83>] skge_xmit_frame+0x163/0x560 [skge] [<ffffffff815e8330>] dev_hard_start_xmit+0x260/0x6f0 [<ffffffff8160bb0e>] sch_direct_xmit+0xfe/0x2a0 [<ffffffff815e8a07>] dev_queue_xmit+0x247/0x970 …
(In reply to comment #0) […] > > Actual results: > The only side effect that has been observed is the reduced flow of data. > Network interface behaves as 100Mb/s, therefore slower than it should be - > 1000Mb/s. > > Expected results: > Speed: 1000Mb/s, that is in practice ~300Mb/s. > OK. Network throughput is related to the kernel debugging facilities. So, please disregard the speed issue.
Unfortunately, this proved to be a bug, after all. The most beautiful part, after the patches have been applied, only now the module(skge) is completely unusable. Maintainer claims that in his case now everything is working properly, but mine is just the opposite. And such a broken module has now become part of the 3.11 series kernel. The tragicomic part, I'm the one who reported this bug in the first place. Hilarious. :) A complete thread is here: http://www.spinics.net/lists/netdev/msg245381.html poma
Everything that has a beginning has an end. poma
Thanks.