ZFS boot problems with memory > 1MB

On Tuesday 23 February 2010 10:28:49 am Brandon Gooch wrote:
> On Tue, Feb 23, 2010 at 7:29 AM, Andriy Gapon <avg_at_icyb.net.ua> wrote:
> > on 23/02/2010 13:18 Renato Botelho said the following:
> >> On Mon, Feb 22, 2010 at 7:35 PM, Chris Hedley
> >> <freebsd-current_at_chrishedley.com> wrote:
> > [snip]
> >>> Do you have USB legacy support enabled in your BIOS?  I'm not sure if
> >>> there's an option for the loader to use USB devices natively, but the BIOS's
> >>> legacy option where it provides AT/PS2 emulation is probably the easiest way
> >>> to get the keyboard working.
> >>
> >> Yes, I do, but it seems to be a regression on FreeBSD itself, I had this problem
> >> in the past and I checked the same things i need to check in the past again and
> >> everything is fine.
> >
> > A more precise way to state that would be "a regression in FreeBSD boot/loader".
> > I think that you are referring to the issue that was fixed by r189017.
> > It might be worthwhile investigating what was done in that revision and what
> > happened in sys/boot code since then.
> >
> > One possibility is that your BIOS uses memory above 1MB for USB emulation, but
> > doesn't mark that memory as used in system memory map.  In that case that memory
> > could be overwritten by the loader.  If that's true then the blame is on the BIOS.
> >  Alternatively, our code might be parsing the system memory map incorrectly.
> > But I am just making wild guesses here.
> >
> 
> I don't know if it is at all related, but this commit has caused
> problems for me booting at least one of my machines:
> 
> http://svn.freebsd.org/viewvc/base/head/sys/boot/i386/zfsboot/zfsboot.c?r1=199714&r2=200309
> 
> Commit message:
> 
> Revision 200309 - (view) (annotate) - [select for diffs]
> Modified Wed Dec 9 20:36:56 2009 UTC (2 months, 2 weeks ago) by jhb
> File length: 24893 byte(s)
> Diff to previous 199714
> - Port bios_getmem() from libi386 to {gpt,}zfsboot() and use it to
>   safely allocate a heap region above 1MB.  This enables {gpt,}zfsboot()
>   to allocate much larger buffers than before.
> - Use a larger buffer (1MB instead of 128K) for temporary ZFS buffers.  This
>   allows more reliable reading of compressed files in a raidz/raidz2 pool.
> 
> Submitted by:	Matt Reimer  mattjreimer of gmail
> MFC after:	1 week

Starting a new thread, which problems are you seeing with this change?  ZFS is
a good bit more memory hungry than UFS, so it really needs to use high memory
for its heap.  Also, I wonder if you still have problems if you use the older
zfsboot with the newer zfsloader?  Finally, you need to use disklabel -B or
some such to update the zfsboot bits for this change to take effect.

-- 
John Baldwin