Performance of SheevaPlug on 8-stable
Warner Losh
imp at bsdimp.com
Tue Jan 31 16:42:10 UTC 2012
On Jan 31, 2012, at 8:54 AM, Ian Lepore wrote:
> On Mon, 2012-01-30 at 22:39 -0700, Warner Losh wrote:
>> Hi Ian,
>>
>> Do you have any data on what 9.0 does?
>>
>> Warner
>
> No. Do you have reason to believe it will be different than 8.x?
>
> It would be a major effort right now to get anything later than 8.2
> built and running on one of our arm platforms. Maybe not as hard as the
> 6.2 -> 8.2 conversion was, but we're still carrying a lot of diffs from
> stock FreeBSD that have to be analyzed and merged by hand. Actually
> before that can even happen I'd have to grab a snapshot of 9.0 and do an
> svn->Hg conversion to even be able to start merging the diffs (and I'm
> hardly an Hg expert, but those in the company who are let me know last
> week that they're just as busy as me, and I'm on my own for this kind of
> work). It's work I want to do, but I suspect it's going to happen later
> rather than sooner because product deadlines are beginning to loom and
> my ability to spend most of my time working on the OS side of things is
> waning.
>
> If there are some specific changes you've got in mind that affect this
> problem I might be able to backport and test them faster than I could
> get a full 9.0 or -current build environment working, just point me at
> them.
I thought that we'd done a root cause of this and had put a fix into the vm system. Lemme look...
------------------------------------------------------------------------
r224049 | marcel | 2011-07-14 20:11:26 -0600 (Thu, 14 Jul 2011) | 2 lines
In pmap_protect(), don't call vm_page_dirty() if the page is unmanaged.
------------------------------------------------------------------------
r221844 | cognet | 2011-05-13 09:54:12 -0600 (Fri, 13 May 2011) | 4 lines
In pmap_change_wiring(), use the right argument for pmap_modify_pv().
It only worked because the only consumer calls pmap_change_wiring() to remove
the wiring.
------------------------------------------------------------------------
r212507 | cognet | 2010-09-12 14:46:32 -0600 (Sun, 12 Sep 2010) | 5 lines
In pmap_remove_all(), do not decrease pm_stats.wired_count if the mapping was
wired, as it's been done later in pmap_nuke_pv().
Submitted by: Mark Tinguely
------------------------------------------------------------------------
r209223 | cognet | 2010-06-15 16:16:02 -0600 (Tue, 15 Jun 2010) | 4 lines
Turn off cache if there's more than one kernel mapping, and one is writable.
Submitted by: Mark Tinguely
------------------------------------------------------------------------
r205028 | raj | 2010-03-11 14:16:54 -0700 (Thu, 11 Mar 2010) | 12 lines
Fix ARM cache handling yet more.
1) vm_machdep.c: remove the dangling allocations so they do not
un-necessarily turn off the cache upon consecutive access.
2) busdma_machdep.c: remove the same amount than shadow mapped.
Reported by: Maks Verver
Submitted by: Mark Tinguely
Reviewed by: Grzegorz Bernacki
MFC after: 3 days
------------------------------------------------------------------------
r203637 | raj | 2010-02-07 13:48:57 -0700 (Sun, 07 Feb 2010) | 19 lines
Improve checking whether an ARM VA has a valid mapping before performing cache
sync.
VIPT/PIPT caches need valid VA-PA mapping in PTE for a cache operation to
succeed (unlike VIVT). Prior to this fix pmap was using l2pte_valid() for that
check, but this is not sufficient as the function merely checks if a PTE
exists (there can be existing but _invalid_ entries in the table).
A new pmap_has_valid_mapping() routine is introduced to do this job right by
checking proper PTE flags.
Among other potential problems this cures coherency issues with L2 caches on
MV-78100.
Submitted by: Grzegorz Bernacki, Piotr Ziecik
Reviewed, tested by: marcel
Obtained from: Semihalf
MFC after: 1 week
Only the last two have MFC, so you can start there and see which of these changes are in...
Just thought you might have a reference board that would be easy to test...
Warner
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