Re: [RFC] respect the referenced bit of KVM guest pages?

From: KOSAKI Motohiro
Date: Sun Sep 13 2009 - 12:30:37 EST


Hi Jeff,

> A side note - I've been doing some tracing and shrink_active_list is called a humongous number of times (25000-ish during a ~90 kvm run), with a net result of zero pages moved nearly all the time.  Your test is rescuing essentially all candidate pages from the inactive list.  Right now, I have the VM_EXEC || PageAnon version of your test.

Sorry for the long delayed replay.
I made reproduce environment today. but I don't have luck. I didn't
reproduce stack refault issue.
Could you please explain detailed reproduce way and your analysis way?

My environment is,
x86_64 CPUx4 MEM 6G
userland: fedora11
kernel: latest mmotm

cgroup size: 128M
guest mem: 256M
CONFIG_KSM=n

My result,
- plenty anon and file fault happen. but it is ideal. it is caused
by demand paging.
- do_anonymous_page almost doesn't handle stack fault. both host and guest.
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