http://kvm.qumranet.com
Linux Kernel-based Virtual Machine.
Uses a modified QEmu and hardware virtualisation support in AMD and
Intel CPUs to effectively turn the Linux kernel into a hypervisor.
The VMs run as user processes on top of a (fairly) standard Linux
install.
Freddie
On 6/6/08, Matthew Dillon <[EMAIL PROTECTED]> wrote:
>
> :I've managed to get gdb attached and get some information.
> :
> :The kernel is getting caught in a while loop in lwkt_acquire. I can
> :reliably trigger this with with a "make -j8 buildworld" under a SMP
> :kernel (Otherwise identical to GENERIC, no optimisations.) The OS is
> :completely unresponsive and all four cpu cores are running at 100%.
> :
> :I've included the debug information.
> :
> :Program received signal SIGINT, Interrupt.
> :lwkt_acquire (td=0xc6a59e70) at /usr/src/sys/kern/lwkt_thread.c:1048
> :1048 while (td->td_flags & (TDF_RUNNING|TDF_PREEMPT_LOCK))
> :(gdb) l
> :1043 mygd = mycpu;
> :1044 if (gd != mycpu) {
> :1045 cpu_lfence();
> :1046 KKASSERT((td->td_flags & TDF_RUNQ) == 0);
> :1047 crit_enter_gd(mygd);
> :1048 while (td->td_flags & (TDF_RUNNING|TDF_PREEMPT_LOCK))
> :1049 cpu_lfence();
> :1050 td->td_gd = mygd;
> :1051 TAILQ_INSERT_TAIL(&mygd->gd_tdallq, td, td_allq);
> :1052 td->td_flags &= ~TDF_MIGRATING;
> :(gdb) p td->td_flags
> :$1 = 8390177
> :(gdb) p td
> :$2 = (thread_t) 0xc6a59e70
> :(gdb) bt
> :#0 lwkt_acquire (td=0xc6a59e70) at /usr/src/sys/kern/lwkt_thread.c:1048
> :#1 0xc02c66af in bsd4_select_curproc (gd=0xff800000) at
> :/usr/src/sys/kern/usched_bsd4.c:358
> :#2 0xc02c6829 in bsd4_release_curproc (lp=0xea634c00) at
> :/usr/src/sys/kern/usched_bsd4.c:322
> :#3 0xc04b8239 in passive_release (td=0xdfe8aba0) at
> :..
> :
> :Continuing execution does not appear to cause any problems.
> :I can provide additional debugging info if required but I'm unsure of
> :how to proceed with this myself.
> :
> :Regards
> :
> :Gary
>
> This is great info. One thing, what do you mean by 'KVM'? What
> is DragonFly running under, exactly?
>
> I think once I understand the environment I may be able to figure out
> why the acquisition loop is blowing up.
>
> -Matt
> Matthew Dillon
> <[EMAIL PROTECTED]>
>
--
Freddie Cash
[EMAIL PROTECTED]
