Hi, On Thu, Nov 11, 2010 at 2:02 PM, Tim Blechmann <tim@xxxxxxxxxx> wrote: > hi all, > > i am using tn rt61pci driver and besides having not the best wireless > performance, it network transfer sometimes disturbs the audio playback on my > machine. sometimes it works fine, but the machine can get into a state, where i > will have to reboot the machine to get back to normal. i suppose, this is > because of the rt61pci driver. > > in general if found, that the specific irq thread produces a lot of interrupts > and does quite a lot of work. the specific irq thread takes quite some cpu time > (currently i have an uptime of 5 hours and the irq thread used 4 minutes of cpu > time) and about 200 interupts are issued per second: You get ~200 interrupts/second from rt61pci while the device is idle? Or while transmitting/receiving? > cat /proc/interrupts |grep 16\: && sleep 1 && cat /proc/interrupts | grep 16\: > 16: 0 5140126 0 0 IO-APIC-fasteoi > uhci_hcd:usb3, ahci, 0000:08:00.0 > 16: 0 5140357 0 0 IO-APIC-fasteoi > uhci_hcd:usb3, ahci, 0000:08:00.0 > > using perf, i get the following data about the spent cpu time: > # Events: 106 cycles > # > # Overhead Command Shared Object Symbol > # ........ ............... ................. ...... > # > 61.17% irq/16-0000:08: [rt61pci] [k] rt61pci_interrupt_thread > 12.77% irq/16-0000:08: [rt61pci] [k] rt61pci_set_device_state > 3.72% irq/16-0000:08: [kernel.kallsyms] [k] __ticket_spin_lock > 3.17% irq/16-0000:08: [kernel.kallsyms] [k] local_bh_disable > 2.14% irq/16-0000:08: [kernel.kallsyms] [k] schedule > 1.81% irq/16-0000:08: [rt61pci] [k] rt61pci_kick_tx_queue > 1.50% irq/16-0000:08: [mac80211] [k] prepare_for_handlers > 1.38% irq/16-0000:08: [rt2x00pci] [k] rt2x00pci_rxdone > 1.03% irq/16-0000:08: [kernel.kallsyms] [k] __ticket_spin_unlock > 0.87% irq/16-0000:08: [kernel.kallsyms] [k] __inet_lookup_established > 0.87% irq/16-0000:08: [kernel.kallsyms] [k] tcp_event_data_recv > 0.82% irq/16-0000:08: [kernel.kallsyms] [k] irq_thread > 0.66% irq/16-0000:08: [kernel.kallsyms] [k] update_curr_rt > 0.64% irq/16-0000:08: [rt2x00lib] [k] rt2x00lib_rxdone > 0.64% irq/16-0000:08: [kernel.kallsyms] [k] mod_timer > 0.51% irq/16-0000:08: [kernel.kallsyms] [k] pick_next_task_rt > 0.51% irq/16-0000:08: [kernel.kallsyms] [k] cpupri_set > 0.51% irq/16-0000:08: [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore > 0.50% irq/16-0000:08: [kernel.kallsyms] [k] hrtick_update > 0.49% irq/16-0000:08: [kernel.kallsyms] [k] __phys_addr > 0.49% irq/16-0000:08: [kernel.kallsyms] [k] update_shares > 0.49% irq/16-0000:08: [kernel.kallsyms] [k] dequeue_task > 0.49% irq/16-0000:08: [kernel.kallsyms] [k] dequeue_rt_stack > 0.49% irq/16-0000:08: [kernel.kallsyms] [k] skb_release_data > 0.44% irq/16-0000:08: [kernel.kallsyms] [k] load_balance > 0.40% irq/16-0000:08: [kernel.kallsyms] [k] memcpy > 0.36% irq/16-0000:08: [kernel.kallsyms] [k] map_single > 0.36% irq/16-0000:08: [kernel.kallsyms] [k] ip_output > 0.36% irq/16-0000:08: [kernel.kallsyms] [k] tcp_ack > 0.22% irq/16-0000:08: [mac80211] [k] minstrel_ht_tx_status > 0.22% irq/16-0000:08: [kernel.kallsyms] [k] tcp_v4_rcv > 0.00% irq/16-0000:08: [kernel.kallsyms] [k] native_write_msr_safe > > not sure, if this is really helpful, but this amount of interrupts doesn't look > good to me. if i can be on any further help to track down this issue, i would be > happy to assist. Looks to me as if the interrupt thread gets scheduled but doesn't do anything useful as otherwise we should also see the rxdone/txdone functions etc in the perf output. Mind to put a (maybe rate limited) printk into the interrupt thread that prints out "reg" and "reg_mcu" so that we can see which interrupts get triggered? Helmut -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
