From: Jia Rao [mailto:rickenrao@xxxxxxxxx
Sent: Tuesday, November 10,
2009 9:23 AM
How does the self-ballooning daemon calculate the
I am wondering how does the
self-ballooning daemon calculate the selftarget for the guest
>From the README of balloon driver, it seems that selftarget
is determined by Committed_AS in meminfo.
I did some test on tpcc
benchmark. the OS is initially allocated 2048MB of memory, and then I
enabled the selfballooning by echo 1 > /proc/xen/balloon.
configuration of xenballoond.conf is the default except that I enabled
The following is the meminfo
Buffers: 13260 kB
Inactive: 213584 kB
LowFree: 1183888 kB
SwapFree: 2097132 kB
Mapped: 14228 kB
CommitLimit: 3067132 kB
VmallocTotal: 34359738367 kB
VmallocChunk: 34359737159 kB
It seems that the
self-balloon driver is reluctant to give up free memory from the guest
although the Committed_AS is small. The self-ballooning did changed the
selftarget to something like 1.6GB but quickly changed to and fix at
According to the meminfo, we should be able to give up
at least 800MB back to the VMM.
FYI: xen 3.3.1, linux 184.108.40.206 in
both dom0 and domu.