On Sat, 2015-08-01 at 15:09 -0700, Yonik Seeley wrote: > I also investigated going the other way and tracking a List<int[]> and > allocating in smaller chunks (and even having a memory pool to pull > the fixed size chunks from) but it was slower on my first attempt and > I haven't returned to try more variants yet. It *feels* like we > should be able to get overall speedups by allocating in 8K chunks or > so when the effects of memory bandwidth (the cost of zeroing) and GC > are considered.
Chunked allocations of int[] would still have the problem of having the copy-to-bitmap step if the result set gets too big. Chunks might work better with the garbage collector, compared to the current solution, but I greatly prefer the idea of re-using structures. That being said, I realize that it is not simple to choose the proper strategy: http://stackoverflow.com/questions/1955322/at-what-point-is-it-worth-reusing-arrays-in-java In the case of an update-tracked structure, the cost of zeroing is linear to the amount of changed values. This makes it even harder to determine the best strategy as it will be tied to concrete index size and query pattern. - Toke Eskildsen, State and University Library, Denmark --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
