From: Paul Mackerras <paulus@ozlabs.org>
To: kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 0/4] KVM: PPC: Book3S HV: Improve live migration of radix guests
Date: Tue, 18 Dec 2018 01:02:11 +0000 [thread overview]
Message-ID: <20181218010211.GD25748@blackberry> (raw)
In-Reply-To: <20181212041430.GA22265@blackberry>
On Wed, Dec 12, 2018 at 03:14:30PM +1100, Paul Mackerras wrote:
> We have observed that live migration of radix guests tends to converge
> slowly and sometimes doesn't converge at all. This appears to be due
> largely to the fact that if the host is using transparent huge pages,
> page dirtiness only gets tracked with a 2MB granularity for the parts
> of the guest memory that are mapped using 2MB pages. The fix is to
> break down the mappings in the partition-scoped page tables to 64k
> pages (or 4k pages if 4k is the system page size). This is
> accomplished by flushing the partition-scoped page tables when turning
> dirty page tracking on or off, and by only inserting small-page PTEs
> into the partition-scoped page tables while dirty page tracking is
> enabled.
>
> Paul.
Series applied to my kvm-ppc-next branch.
Paul.
prev parent reply other threads:[~2018-12-18 1:02 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-12 4:14 [PATCH 0/4] KVM: PPC: Book3S HV: Improve live migration of radix guests Paul Mackerras
2018-12-12 4:17 ` [PATCH 4/4] KVM: PPC: Book3S HV: Flush guest mappings when turning dirty tracking on/off Paul Mackerras
2018-12-12 5:22 ` Suraj Jitindar Singh
2018-12-12 23:54 ` David Gibson
2020-04-28 15:57 ` Laurent Vivier
2020-05-06 5:12 ` Paul Mackerras
[not found] ` <e7aae742-d189-2882-5c41-3dd993c029bb@redhat.com>
2020-05-27 10:23 ` Paul Mackerras
2018-12-18 1:02 ` Paul Mackerras [this message]
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