Re: [Zope3-dev] Re: [Zope-dev] 64-bit BTrees
Previously Chris Withers wrote: The implicit change to make them all 64-bits which results in some unknown slowdown for all I BTree users seems a bit too scary to bite off... Has anyone done any benchmarks to prove that 64-bits is slower or faster? It would be interesting to see benchmarks on modern 32bit and a 64bit systems. Until then it's all hand-waiving. Wichert. -- Wichert Akkerman [EMAIL PROTECTED]It is simple to make things. http://www.wiggy.net/ It is hard to make things simple. ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope3-dev] Re: [Zope-dev] 64-bit BTrees
Wichert Akkerman wrote: Previously Chris Withers wrote: The implicit change to make them all 64-bits which results in some unknown slowdown for all I BTree users seems a bit too scary to bite off... Has anyone done any benchmarks to prove that 64-bits is slower or faster? It would be interesting to see benchmarks on modern 32bit and a 64bit systems. Until then it's all hand-waiving. One data point: on my AMD 64 box, when I run 32 bit Linux, I get about 30,000 pystones, while 64 bit Linux yields 50,000 pystones. This doesn't mean 64 bit code is necessarily faster, but it does suggest that 64 bit CPUs prefer 64 bit code. Shane ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] 64-bit BTrees
Fred Drake wrote: (possibly named LLBTree, LOBTree, and OLBTree). For my half-penny's worth, this is the way I'd like to see it go. Explicit is better than implicit and all that. If you need more than 32-bits, you can explicitly use them. The implicit change to make them all 64-bits which results in some unknown slowdown for all I BTree users seems a bit too scary to bite off... Chris -- Simplistix - Content Management, Zope Python Consulting - http://www.simplistix.co.uk ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
[Zope-dev] 64-bit BTrees
I have a need for 64-bit BTrees (at least for IOBTree and OIBTree), and I'm not the first. I've created a feature development branch for this, and checked in my initial implementation. I've modified the existing code to use PY_LONG_LONG instead of int for the key and/or value type; there's no longer a 32-bit version in the modified code. Any Python int or long that can fit in 64 bits is accepted; ValueError is raised for values that require 65 bits (or more). Keys and values that can be reported as Python ints are, and longs are only returned when the value cannot be converted to a Python int. This can have a substantial effect on memory consumption, since keys and/or values now take twice the space. There may be performance issues as well, but those have not been tested. There are new unit tests, but more are likely needed. If you're interested in getting the code from Subversion, it's available at: svn://svn.zope.org/repos/main/ZODB/branches/fdrake-64bits/ Ideally, this or some variation on this could be folded back into the main development for ZODB. If this is objectionable, making 64-bit btrees available would require introducing new versions of the btrees (possibly named LLBTree, LOBTree, and OLBTree). I welcome comments. -Fred -- Fred L. Drake, Jr.fdrake at gmail.com Don't let schooling interfere with your education. -- Mark Twain ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
