hugetlbfs and KSM
Hi,
running Debian Squeeze with a 2.6.32-3-amd64 kernel and qemu-kvm 0.12.3 I enabled hugetlbfs on a rather small box with about five similar VMs today (all Debian Squeeze amd64, but different services)
Pro:
* system load on the host has gone way down (by about 50%)
Contra:
* KSM seems to be largely ineffective (100MB saved -> 1.3MB saved)
Am I doing something wrong? Is this a bug? Is this generally impossible with large pages (which might explain the lower load on the host, if large pages are not scanned)? Or is it just way less likely to have identical pages at that size?
Bernhard
Quoted 6 lines · * Bernhard Schmidt ([email protected]) wrote:
* KSM seems to be largely ineffective (100MB saved -> 1.3MB saved)
Am I doing something wrong? Is this a bug? Is this generally impossible with large pages (which might explain the lower load on the host, if large pages are not scanned)? Or is it just way less likely to have identical pages at that size?
KSM only scans and merges 4k pages.