Re: [PATCH v2] makedumpfile: request the kernel do page scans

Cliff Wickman
2013-01-07T13:37:03Z

An update on testing thise patches:

> This version of the patch improves the consolidation of the mem_map table
> that is passed to the kernel. See make_kernel_mmap().
> Particularly the seemingly duplicate pfn ranges generated on an older
> (2.6.32-based, rhel6) kernel.

On a 2TB machine (idle) machine:
the crash kernel ran successfully in 512M
the scan for unnecessary pages takes about 40 seconds
it was a single scan, not cyclic

On a 16TB machine (idle) machine:
the crash kernel ran successfully in 512M
there is a pause of about 4 minutes during makedumpfile initialization
the scan for unnecessary pages takes about 4.8 minutes
it was a single scan, not cyclic