From: Keir Fraser <keir.xen@gmail.com>
To: Gianni Tedesco <gianni.tedesco@citrix.com>,
Xen Devel <xen-devel@lists.xensource.com>
Cc: Tim Deegan <Tim.Deegan@eu.citrix.com>, Keir Fraser <keir.fraser@xen.org>
Subject: Re: xc: error: xc_machphys_mfn_list: 83 != 129 when suspending 32GB PV DomU
Date: Fri, 11 Mar 2011 19:21:35 +0000 [thread overview]
Message-ID: <C9A026BF.14A37%keir.xen@gmail.com> (raw)
In-Reply-To: <1299869540.17229.72.camel@qabil.uk.xensource.com>
On 11/03/2011 18:52, "Gianni Tedesco" <gianni.tedesco@citrix.com> wrote:
> Further debugging reveals the variables are set as such:
> (XEN) compat_machine_to_phys_mapping = 18446606377058041856
> (XEN) max_page = 67272704
> (XEN) MACH2PHYS_COMPAT_NR_ENTRIES(current->domain) = 43515904
> (XEN) RDWR_COMPAT_MPT_VIRT_START = 18446606377058041856
> (XEN) RDWR_COMPAT_MPT_VIRT_END = 18446606378131783680
> (XEN) limit = 18446606377232105472, (1 << L2_PAGETABLE_SHIFT) = 2097152
>
> Could it be that the compat mach-to-phys conversion table size of 1GB is
> too small?
It is insufficient to cover all of the system's memory. The reason for the
limit is that a 1GB M2P table is all that is reasonable to map into a 32-bit
domain's address space while still leaving space for the guest's own
mappings.
We could make the compat m2p bigger solely for mapping by dom0 when doing
save/restore? However, you'd likely still soon hit the mmap limit for the
save/restore process in dom0. It might extend the lifetime of your 32-bit
dom0 for a bit longer however. Long enough for the lightweight HVM container
for PV guests work to get checked in and make our PV 64-bit guest
performance better.
-- Keir
> Or that there exists some other arbitrary limit on the size
> of domains that can be suspended [when using a 32bit dom0] ?
next prev parent reply other threads:[~2011-03-11 19:21 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-11 18:52 xc: error: xc_machphys_mfn_list: 83 != 129 when suspending 32GB PV DomU Gianni Tedesco
2011-03-11 19:21 ` Keir Fraser [this message]
2011-03-14 10:20 ` Ian Campbell
2011-03-14 15:05 ` [PATCH]: Allow tools to map arbitrarily large machphys_mfn_list on 32bit dom0 Gianni Tedesco
2011-03-14 15:08 ` Keir Fraser
2011-03-14 15:11 ` Ian Campbell
2011-03-14 15:19 ` Gianni Tedesco
2011-03-14 15:55 ` Jan Beulich
2011-03-14 16:03 ` Ian Campbell
2011-03-14 16:22 ` Jan Beulich
2011-03-14 16:33 ` Ian Campbell
2011-03-14 16:54 ` Keir Fraser
2011-03-14 17:00 ` Jan Beulich
2011-03-14 17:09 ` Gianni Tedesco
2011-03-14 16:58 ` Jan Beulich
2011-03-14 17:11 ` Gianni Tedesco
2011-03-15 15:00 ` Ian Campbell
2011-03-15 15:09 ` Jan Beulich
2011-03-15 15:14 ` Ian Campbell
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