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An unexpected perf feature
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
I guess you think java applications are few. :)
That way lies madness
Posted Sep 2, 2011 22:47 UTC (Fri) by dlang (✭ supporter ✭, #313)
remember that visualization is supposed to be the wave of the future, especially for things in datacenters. part of the way this works is that you slice up the memory available on a server to allocate it between many more small servers. most such servers end up with less than 4G per virtual server and what we are talking about for x32 is 4G per _application_ (not counting OS buffering, kernel allocations, or any other overhead) this is a lot more elbow room.
not every application can fit in 4G, but when you really look at it, a surprising number of them will.
and pointer-heavy things like Java are especially likely to benifit from the smaller pointers of x32
Posted Sep 5, 2011 7:48 UTC (Mon) by Cyberax (✭ supporter ✭, #52523)
Posted Sep 5, 2011 22:38 UTC (Mon) by intgr (subscriber, #39733)
Offtopic, but interesting: 64-bit Java already offers the -XX:+UseCompressedOops option which turns on pointer compression. By dropping 3 bits from the least significant end of the address, it can address 32GB of memory using 32-bit pointer fields.
Posted Sep 6, 2011 14:35 UTC (Tue) by Cyberax (✭ supporter ✭, #52523)
Posted Apr 2, 2012 14:30 UTC (Mon) by Richard_J_Neill (subscriber, #23093)
Posted Apr 3, 2012 20:49 UTC (Tue) by ibukanov (subscriber, #3942)
On modern CPU memory is addressed internally by cache lines that are typically 16-32-64 bytes in size. On x86 the byte access is just as fast as 32-bit access. Moreover, misaligned access to 32-bit values is allowed and is not costly as long as the variable does not cross the cache line boundary.
Posted May 21, 2012 15:08 UTC (Mon) by mikemol (subscriber, #83507)
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