Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 13 Jun 2014 11:56:23 -0500
From:      Alan Cox <alc@rice.edu>
To:        Hans Petter Selasky <hps@selasky.org>, Ian Lepore <ian@FreeBSD.org>
Cc:        "arm@freebsd.org" <arm@FreeBSD.org>
Subject:   Re: RPI-B VM panic
Message-ID:  <539B2D37.8050407@rice.edu>
In-Reply-To: <539AED38.2000307@selasky.org>
References:  <539170AA.2000109@selasky.org> <5396947A.1060601@selasky.org>	 <5396A0D1.80309@selasky.org> <5396AF63.6040209@selasky.org>	 <8BA66A45-E08A-475D-A1FA-5047E862681E@rice.edu>	 <5398B6EA.9030408@selasky.org>	 <A9433B36-C15C-455E-AB80-3999596936F9@rice.edu>	 <5398BFD9.60502@selasky.org>	 <7390A211-C949-4079-B3DA-BF23798B8992@rice.edu>	 <539942C0.5010706@selasky.org> <5399DF7F.4010501@rice.edu>	 <5399E349.5050600@selasky.org> <1402594327.20883.216.camel@revolution.hippie.lan> <5399E660.5050207@selasky.org> <5399E901.1080805@selasky.org> <5399FB57.8090102@rice.edu> <539A140F.6020107@selasky.org> <539ADD04.4000202@selasky.org> <539AED38.2000307@selasky.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On 06/13/2014 07:23, Hans Petter Selasky wrote:
> On 06/13/14 13:14, Hans Petter Selasky wrote:
>> Hi,
>>
>> Some debugging reveals that the previous element has pindex == 0 aswell.
>> So it turns out there can be multiple pages having same pindex, and then
>> the "mpred" logic falls apart :-(
>>
>> --HPS
>>
>
> Hi,
>
> Added some random printfs to vm_xxx.c:
>
> One observation is that allocated pages are busy, and we are not
> waiting for then to become non-busy ?
>

By default, we mark a page as busy when we allocate it.  At the end of
vm_fault(_hold), we unbusy it after it is mapped.

> I cannot debug this further until coming Monday ... Patch suggestions
> are welcome!
>
> It happens approximately 1 of 2 times during boot.
>
> --HPS
>
>
>




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?539B2D37.8050407>