[CFT] ZFS v15 patch (version 3)

[Mickaël Maillot]

patch works fine here on 8-STABLE.
my deadlock probleme seams to be corrected (after 6h of zfs receive +
find | wc -l + many small reads).

2010/7/10 Peter Jeremy <peterjeremy at acm.org>:
> On 2010-Jul-08 23:30:33 +0200, Martin Matuska <mm at FreeBSD.org> wrote:
>>> Looking at the patchset, the most critical issue (IMHO) that doesn't
>>> appear to have been addressed is the interaction between ZFS ARC and
>>> the VM cache used by UFS/NFS: arc_memory_throttle() is still making
>>> decisions solely on the amount of "free" memory, without considering
>>> "inactive" or "cache".  I am running a slight variant of a patch by
> ...
>>Regarding ARC, you might want to try the revision 209227 from head that
>>is scheduled for MFC on 18.7.2010:
>>http://people.freebsd.org/~mm/patches/zfs/head-12636.patch
>
> That patch appears to address issues with unreasonable arc sizing but
> doesn't alter the throttling algorithm: FreeBSD's "traditional" VM
> management algorithm (used by everything except ZFS) minimises space
> marked as "free" by preferentially keeping cached data in the "cache"
> or "inactive" queues.  ZFS uses its own caching which solely uses the
> "free" list to determine memory availability.  This means ZFS can't
> apply any pressure to the FreeBSD VM system and runs in a virtually
> permanent state of memory starvation.
>
> In any case, I have applied that patch as it appears useful.
>
> --
> Peter Jeremy
>