PATCH: increase heap size for (gpt)zfsboot

[John Baldwin]

On Wednesday 09 December 2009 1:00:47 pm Matt Reimer wrote:
> On Wed, Dec 9, 2009 at 7:15 AM, John Baldwin <jhb at freebsd.org> wrote:
> > On Tuesday 08 December 2009 6:06:14 pm Matt Reimer wrote:
> >> On Tue, Dec 8, 2009 at 5:13 AM, John Baldwin <jhb at freebsd.org> wrote:
> >> > On Monday 07 December 2009 7:01:03 pm Matt Reimer wrote:
> >> >> Enlarge the heap size for gptzfsboot and zfsboot. This is necessary so
> >> >> the ZFS code has enough memory to handle decompression and error
> >> >> recovery.
> >> >>
> >> >> Before this patch the heap grew from the end of the (gpt)zfsboot code
> >> >> and static data up to 640KB, possibly overrunning the stack. Now the
> >> >> heap is located at 16MB-64MB.
> >> >>
> >> >> Note that this requires machines with at least 64MB RAM, but this is
> >> >> not likely to be a problem on any machine running ZFS.
> >> >>
> >> >> Sponsored by: VPOP Technologies, Inc.
> >> >>
> >> >> Matt Reimer
> >> >
> >> > Unfortunately the 16M - 64M range may not all be useable RAM.  It may contain
> >> > ACPI tables, etc.  A robust approach would involve walking the SMAP, etc.  I
> >> > just committed some changes to sys/boot/i386/loader/biosmem.c that make it
> >> > smarter about choosing a heap region.  I suggest adopting that algorithm for
> >> > figuring out a safe heap range.  zfsboot and gptzfsboot should have enough
> >> > free space to take the bios_getmem() function.  You can increase the minimum
> >> > heap size beyond 3M if desired (though 3M is the minimum the loader will
> >> > guarantee currently, and if ZFS needs more than that it likely needs to be
> >> > changed in both places).
> >>
> >> Thanks John. I dropped the bios_getmem() into zfsboot.c and it works
> >> for me. How's the attached patch look to you?
> >
> > I tweaked it slightly (memtop* aren't needed for gptboot, and memsize() isn't
> > used anymore).  Can you test the updated version below?
> 
> It works. But making bios_getmem() inline causes a compiler warning:
> 
> /usr/src/sys/boot/i386/gptzfsboot/../zfsboot/zfsboot.c: In function 'main':
> /usr/src/sys/boot/i386/gptzfsboot/../zfsboot/zfsboot.c:353: warning:
> inlining failed in call to 'bios_getmem': --param
> max-inline-insns-single limit reached
> /usr/src/sys/boot/i386/gptzfsboot/../zfsboot/zfsboot.c:620: warning:
> called from here

Ok, the inline is probably not needed for zfsboot since it isn't quite as
space constrained.  I will commit it w/o the inline.

-- 
John Baldwin