[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] Trace buffers no longer working -- What changed?

  • To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
  • From: Rob Gardner <rob.gardner@xxxxxx>
  • Date: Wed, 08 Mar 2006 13:16:09 -0700
  • Delivery-date: Wed, 08 Mar 2006 20:17:00 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>

It has come to my attention that Xenmon and xentrace have stopped working in the latest xen-unstable tree, but I'm not sure precisely when this happened. The problem is that both utilities are failing to map the xen trace buffers into user space. Anyone have any idea what might have changed recently that could have caused this? The trace buffer allocation code in the hypervisor is using alloc_xenheap_pages() followed by SHARE_PFN_WITH_DOMAIN(), and then the userland apps use xc_map_foreign_range() to get access to the trace buffers. xc_map_foreign_range() uses ioctl(IOCTL_PRIVCMD_MMAP) which is failing with errno 14 (bad address). In particular, the privcmd ioctl uses direct_remap_pfn_range() which is actually returning the error. I kind of suspect that there's nothing wrong at the userland side of things, but something is going wrong when the memory is allocated and "shared". Can anybody help?


Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.