Re: [Crash-utility] Re: [Xen-devel] crash can't analyze memory dumpfile of Xen

Itsuro ODA wrote: > Hi, > > I found the root cause of this problem is that the value of "PERCPU_SHIFT" > was changed to 13 from 12. > > The quick workaround is to apply the following patch to the crash command: > ---------------------------------------------------------------------- > --- xen_hyper_defs.h.org 2008-10-03 14:46:28.000000000 +0900 > +++ xen_hyper_defs.h 2008-10-03 14:46:50.000000000 +0900 > @@ -134,7 +134,7 @@ > #endif > > #if defined(X86) || defined(X86_64) > -#define XEN_HYPER_PERCPU_SHIFT 12 > +#define XEN_HYPER_PERCPU_SHIFT 13 > #define xen_hyper_per_cpu(var, cpu) \ > ((ulong)(var) + (((ulong)(cpu))<<XEN_HYPER_PERCPU_SHIFT)) > #elif defined(IA64) > ------------------------------------------------------------------------ > > I need to think the backword compatibility. I wonder how to determine > the value of "PERCPU_SHIFT". The change of "PERCPU_SHIFT" was made at > a certain point of xen-unstable before xen-3.3 release. The xen version > number (3.3) can't use as key... I will consider more... From the crash utility perspective, and looking at the RHEL5 xen sources where these hypervisor definitions exist: #define PERCPU_SIZE (1UL << PERCPU_SHIFT) static void __init percpu_init_areas(void) { unsigned int i, data_size = __per_cpu_data_end - __per_cpu_start; unsigned int first_unused; BUG_ON(data_size > PERCPU_SIZE); during initialization you could calculate the difference between the __per_cpu_data_end and __per_cpu_start symbol values, and if it's more than the original 4k size (12), then it must be 13. Dave -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility