Currently a memory segment in memory map with attribute of EFI_MEMORY_UC is denoted as "System RAM" in /proc/iomem, while memory of attribute (EFI_MEMORY_WB|EFI_MEMORY_UC) is also labeled the same. The kexec utility then includes uncached memory as part of vmcore. The kdump kernel may MCA when it tries to save the vmcore to a disk. A normal "cached" access can cause MCAs. Since kexec assembled memory ranges with memory tagged as "System RAM", the uncached memory will be excluded if it is labeled differently. Simon, since only IA64 will create "Uncached RAM" label, i do not make changes to other arch. Our HP machine in the lab is dead. I am sorry that i can not test against other IA64 systems (than SGI's). Feedback is very much appreciated. The corresponding kernel patch is needed to test this kexec patch: http://marc.info/?l=linux-ia64&m=122122791230130&w=2 This patch without the kernel patch will have no effect and do no harm. Signed-off-by: Jay Lan <jlan at sgi.com> -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: UC-mem.kexec Url: http://lists.infradead.org/pipermail/kexec/attachments/20080912/e23bae64/attachment.pl
