Description of problem: Some IA64 machines map all cell-local memory above 4 GB (32 bit limit). However, in most cases, the kernel needs some memory below that limit that is DMA-capable. So in this machine configuration, the crashkernel will be reserved above 4 GB. For machines that use SWIOTLB implementation because they lack an I/O MMU the low memory is required by the SWIOTLB implementation. In that case, it doesn't make sense to reserve the crashkernel at all because it's unusable for kdump. Version-Release number of selected component (if applicable): 2.6.18-92.el5 How reproducible: 100% on certain systems Steps to Reproduce: 1. Boot with crashkernel > 4GB Actual results: Varied -- some systems hang, others panic. Expected results: No hangs or panics Additional info: Upstream patch attached.
Created attachment 305230 [details] Upstream fix for this issue
Doug, do you have an HP system that requires 'machvec=dig' on the kdump boot line? ISTR an issue about adding 'machvec=dig' to the kdump boot line ... P.
Answered my own question ;) https://bugzilla.redhat.com/show_bug.cgi?id=218667 and https://bugzilla.redhat.com/show_bug.cgi?id=218487 P.
Adding jwilson -- when a final patch is posted you'll have to test xen-ia64. P.
Hm... Only machine I've got that requires machvec=dig has only 4GB of memory, not sure what sort of mapping its got... Can probably get a machine in RHTS to work with though. Or do I correctly recall that you have an rx2620 that (according to bug 218667) also needs machvec=dig?
Yeah -- I'm just about to start testing there. /me is using a larger system to compile ATM. P.
Upstream commit: http://marc.info/?l=git-commits-head&m=121088524228704&w=2
Created attachment 305679 [details] RHEL5 fix for this issue
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
in kernel-2.6.18-107.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5
This bug has been marked for inclusion in the Red Hat Enterprise Linux 5.3 Release Notes. To aid in the development of relevant and accurate release notes, please fill out the "Release Notes" field above with the following 4 pieces of information: Cause: What actions or circumstances cause this bug to present. Consequence: What happens when the bug presents. Fix: What was done to fix the bug. Result: What now happens when the actions or circumstances above occur. (NB: this is not the same as 'the bug doesn't present anymore')
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2009-0225.html