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Subject: Re: svn commit: r319702 - head/sys/vm
From: Alan Cox <alc@rice.edu>
In-Reply-To: <6910627.IXO0pzjk4q@ralph.baldwin.cx>
Date: Thu, 8 Jun 2017 17:07:40 -0500
Cc: Bryan Drewery <bdrewery@freebsd.org>, src-committers@freebsd.org,
 svn-src-all@freebsd.org, svn-src-head@freebsd.org
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> On Jun 8, 2017, at 2:37 PM, John Baldwin <jhb@freebsd.org> wrote:
>=20
> On Thursday, June 08, 2017 12:55:45 PM Bryan Drewery wrote:
>> On 6/8/17 12:18 PM, John Baldwin wrote:
>>> Author: jhb
>>> Date: Thu Jun  8 16:18:41 2017
>>> New Revision: 319702
>>> URL: https://svnweb.freebsd.org/changeset/base/319702
>>>=20
>>> Log:
>>>  Fix an off-by-one error in the VM page array on some systems.
>>>=20
>>>  r31386 changed how the size of the VM page array was calculated to =
be
>>>  less wasteful.=20
>>=20
>> r313186
>=20
> Oops.  FWIW, this commit fixes a reliable panic booting mips and =
mips64
> kernels under qemu.  Adrian also reported the same panic on real mips
> hardware.
>=20

Any architecture on which we don=E2=80=99t have superpage reservations =
enabled could experience the panic at boot time.  Amd64, arm, arm64, =
i386, and sparc64 would never panic because of the memory allocated for =
the reservation array.=20