[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] vpmu=1 and running 'perf top' within a PVHVM guest eventually hangs dom0 and hypervisor has stuck vCPUS. Romley-EP (model=45, stepping=2)
Am Dienstag 12 MÃrz 2013, 16:54:11 schrieb Boris Ostrovsky: > On 03/12/2013 04:31 PM, Konrad Rzeszutek Wilk wrote: > > On Tue, Mar 12, 2013 at 02:50:59PM -0400, Boris Ostrovsky wrote: > >> On 03/12/2013 01:30 PM, Konrad Rzeszutek Wilk wrote: > >>> This issue I am encountering seems to only happen on multi-socket > >>> machines. > >> I believe I was able to reproduce this (once) on my laptop. > >> > >>> It also does not help that the only multi-socket box I have is > >>> an Romley-EP (so two socket SandyBridge CPUs). The other > >>> SandyBridge boxes I've (one socket) are not showing this. Granted > >>> they are also a different model (42). > >>> > >>> The problem is that when I run 'perf top' within an SMP PVHVM > >>> guest, after a couple of seconds or minutes the guest hangs. > >>> Hypervisor ends up stuck too looping, and then the dom0 ends > >>> up hanging as well. > >>> > >>> Dumping the cpu registers (Ctrl-A x3, then 'd' > >>> shows that the guest is pretty firmly stuck in vmx_vmexit_handler: > >>> > >>> (XEN) [<ffff82c4c01d386f>] vmx_vmexit_handler+0x22f/0x174 > >> And in my case this address is the second instruction after STI, i.e. we > >> are right at the point where interrupts got enabled. > >> > >> So I am wondering whether this has something to do with the counter > >> overflow interrupt (which I believe is an NMI). > > Interestingly enough, if I run the PVHVM guest with 'nowatchdog' > > it runs fine! > > I think by default perf top runs off timer interrupt so it does not use > HW counters. But watchdog > is implemented on top of the counters so perhaps it fires the interrupt > at a bad time, messing > something up. This looks like a strange behavior we had on nehalem cpus see http://lists.xen.org/archives/html/xen-devel/2010-11/msg01157.html For this I added a quirk, see check_pmc_quirk() in vpmu_core2.c The model 42 is in the quirk list and it seems to work but Romley-EP is model 43 I think which is not in the list. Maybe you should add this model and give it a try. Dietmar. -- Company details: http://ts.fujitsu.com/imprint.html _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |