Re: Early hang with 2.6.21-rc4-rt1

2007-03-30 Thread Ingo Molnar
* Ingo Molnar <[EMAIL PROTECTED]> wrote: > > Great, thanks ... I'm not sure which of the 2 patches fixed things, > > but I now got the following trace. I've not really analyzed this, > > but it definitely looks like tun_init() is doing something fishy... > > ("149776 us maximum-latency"!!) >

Re: Early hang with 2.6.21-rc4-rt1

2007-03-30 Thread Ingo Molnar
* Roland Dreier <[EMAIL PROTECTED]> wrote: > Great, thanks ... I'm not sure which of the 2 patches fixed things, > but I now got the following trace. I've not really analyzed this, but > it definitely looks like tun_init() is doing something fishy... > ("149776 us maximum-latency"!!) best

Re: Early hang with 2.6.21-rc4-rt1

2007-03-30 Thread Ingo Molnar
* Roland Dreier [EMAIL PROTECTED] wrote: Great, thanks ... I'm not sure which of the 2 patches fixed things, but I now got the following trace. I've not really analyzed this, but it definitely looks like tun_init() is doing something fishy... (149776 us maximum-latency!!) best would be

Re: Early hang with 2.6.21-rc4-rt1

2007-03-30 Thread Ingo Molnar
* Ingo Molnar [EMAIL PROTECTED] wrote: Great, thanks ... I'm not sure which of the 2 patches fixed things, but I now got the following trace. I've not really analyzed this, but it definitely looks like tun_init() is doing something fishy... (149776 us maximum-latency!!) best would

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Roland Dreier
Great, thanks ... I'm not sure which of the 2 patches fixed things, but I now got the following trace. I've not really analyzed this, but it definitely looks like tun_init() is doing something fishy... ("149776 us maximum-latency"!!) - R. [ 272.392694] tun: Universal TUN/TAP device driver,

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Ingo Molnar
* Roland Dreier <[EMAIL PROTECTED]> wrote: > > I finally got curious enough to want to debug why starting kvm with > > tun/tap networking produces a bunch of > > > > rtc: lost some interrupts at 1024Hz. > > > > messages. So I'm assuming it's a ~millisecond irqs-off section > >

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Ingo Molnar
* Roland Dreier <[EMAIL PROTECTED]> wrote: > Any suggestion of where to look? My /proc/latency_trace stays > stubbornly empty -- are there any sysctls I need to change from their > default to get latency tracing? I'm a complete noob when it comes to > the -rt patch, so I'm not sure what the

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Ingo Molnar
* Roland Dreier [EMAIL PROTECTED] wrote: Any suggestion of where to look? My /proc/latency_trace stays stubbornly empty -- are there any sysctls I need to change from their default to get latency tracing? I'm a complete noob when it comes to the -rt patch, so I'm not sure what the right

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Ingo Molnar
* Roland Dreier [EMAIL PROTECTED] wrote: I finally got curious enough to want to debug why starting kvm with tun/tap networking produces a bunch of rtc: lost some interrupts at 1024Hz. messages. So I'm assuming it's a ~millisecond irqs-off section somewhere. And

Re: Early hang with 2.6.21-rc4-rt1

2007-03-27 Thread Roland Dreier
Great, thanks ... I'm not sure which of the 2 patches fixed things, but I now got the following trace. I've not really analyzed this, but it definitely looks like tun_init() is doing something fishy... (149776 us maximum-latency!!) - R. [ 272.392694] tun: Universal TUN/TAP device driver, 1.6

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
> I finally got curious enough to want to debug why starting kvm with > tun/tap networking produces a bunch of > > rtc: lost some interrupts at 1024Hz. > > messages. So I'm assuming it's a ~millisecond irqs-off section > somewhere. And after everything, it's a heisenbug -- I

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
> the 64-bit kernel indeed hangs. Does the patch below fix it for you? Yes, that boots and seems to work fine. Thanks. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
> > I'm trying to use 2.6.21-rc4-rt1 to track down who's keeping > > interrupts off for too long. [...] > btw., is this something you know for sure (if yes, how do you know?) - > or is it that you would like to double-check the irqs-off times of > v2.6.21-to-be? I finally got curious

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Ingo Molnar <[EMAIL PROTECTED]> wrote: > hm - on 32-bit, CRITICAL_IRQSOFF_TIMING+FUNCTION_TRACING works fine > for me. I'll try the 64-bit kernel too. the 64-bit kernel indeed hangs. Does the patch below fix it for you? Ingo Index: linux/kernel/timer.c

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Ingo Molnar <[EMAIL PROTECTED]> wrote: > > OK, another data point. The config below boots and works with > > 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the > > early boot hang. > > ah, i havent tried that option in quite some time, so bitrot is pretty > likely. Does

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Roland Dreier <[EMAIL PROTECTED]> wrote: > I'm trying to use 2.6.21-rc4-rt1 to track down who's keeping > interrupts off for too long. [...] btw., is this something you know for sure (if yes, how do you know?) - or is it that you would like to double-check the irqs-off times of

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Roland Dreier <[EMAIL PROTECTED]> wrote: > OK, another data point. The config below boots and works with > 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the > early boot hang. > > Any idea? ah, i havent tried that option in quite some time, so bitrot is pretty

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Roland Dreier [EMAIL PROTECTED] wrote: OK, another data point. The config below boots and works with 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the early boot hang. Any idea? ah, i havent tried that option in quite some time, so bitrot is pretty likely. Does

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Roland Dreier [EMAIL PROTECTED] wrote: I'm trying to use 2.6.21-rc4-rt1 to track down who's keeping interrupts off for too long. [...] btw., is this something you know for sure (if yes, how do you know?) - or is it that you would like to double-check the irqs-off times of v2.6.21-to-be?

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Ingo Molnar [EMAIL PROTECTED] wrote: OK, another data point. The config below boots and works with 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the early boot hang. ah, i havent tried that option in quite some time, so bitrot is pretty likely. Does the

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Ingo Molnar
* Ingo Molnar [EMAIL PROTECTED] wrote: hm - on 32-bit, CRITICAL_IRQSOFF_TIMING+FUNCTION_TRACING works fine for me. I'll try the 64-bit kernel too. the 64-bit kernel indeed hangs. Does the patch below fix it for you? Ingo Index: linux/kernel/timer.c

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
I'm trying to use 2.6.21-rc4-rt1 to track down who's keeping interrupts off for too long. [...] btw., is this something you know for sure (if yes, how do you know?) - or is it that you would like to double-check the irqs-off times of v2.6.21-to-be? I finally got curious enough to

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
the 64-bit kernel indeed hangs. Does the patch below fix it for you? Yes, that boots and seems to work fine. Thanks. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at

Re: Early hang with 2.6.21-rc4-rt1

2007-03-25 Thread Roland Dreier
I finally got curious enough to want to debug why starting kvm with tun/tap networking produces a bunch of rtc: lost some interrupts at 1024Hz. messages. So I'm assuming it's a ~millisecond irqs-off section somewhere. And after everything, it's a heisenbug -- I repeatably get

Re: Early hang with 2.6.21-rc4-rt1

2007-03-24 Thread Roland Dreier
OK, another data point. The config below boots and works with 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the early boot hang. Any idea? Thanks, Roland # # Automatically generated make config: don't edit # Linux kernel version: 2.6.21-rc4-rt1 # Sat Mar 24 22:06:44 2007

Re: Early hang with 2.6.21-rc4-rt1

2007-03-24 Thread Roland Dreier
OK, another data point. The config below boots and works with 2.6.21-rc4-rt1, but enabling CONFIG_CRITICAL_IRQSOFF_TIMING causes the early boot hang. Any idea? Thanks, Roland # # Automatically generated make config: don't edit # Linux kernel version: 2.6.21-rc4-rt1 # Sat Mar 24 22:06:44 2007