zfs + uma
Andriy Gapon
avg at freebsd.org
Tue Sep 21 07:09:33 UTC 2010
on 21/09/2010 09:39 Jeff Roberson said the following:
> I'm afraid there is not enough context here for me to know what 'the same
> mechanism' is or what solaris does. Can you elaborate?
This was in my first post:
[[[
There is this good book:
http://books.google.com/books?id=r_cecYD4AKkC&printsec=frontcover
Please see section 6.2.4.5 on page 225 and table 6-11 on page 226.
And also this code:
http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/os/kmem.c#971
]]]
> I prefer not to take the weight of specific examples too heavily when
> considering the allocator as it must handle many cases and many types of
> systems. I believe there are cases where you want large allocations to be
> handled by per-cpu caches, regardless of whether ZFS is one such case. If ZFS
> does not need them, then it should simply allocate directly from the VM.
> However, I don't want to introduce some maximum constraint unless it can be
> shown that adequate behavior is not generated from some more adaptable algorithm.
Yes, I agree in general.
But sometimes simplicity has its benefits too as opposed to complex dynamic
behavior that _might_ result from adaptive algorithms.
Anyway, I have some early patches to implement first two of your suggestions and
I am testing them now. Looks good to me so far.
Parameters in the adaptions would probably need some additional tuning.
--
Andriy Gapon
More information about the freebsd-hackers
mailing list