Tim Robbins <[EMAIL PROTECTED]> writes: > It's also the NetBSD fdalloc code. They started with code similar to ours, > in that it did a linear search of the file descriptor array to find an > empty slot and used hints to speed up some common allocation patterns, > then recently switched over to using the multi-level bitmap allocator. > I can't think of any reason why we wouldn't see improvements similar to > what they saw: > http://www.citi.umich.edu/u/provos/benchmark/netbsd-fdalloc.jpg
Having looked at the code, I believe that the graph is the result of an improperly designed benchmark. FreeBSD's performance *with a properly designed benchmark* should be similar to the red line (it's not as bad as it looks; the sharp rise caused by cache trashing occurs around 30k fds which is a pretty respectable number). The same benchmark would show a similar but less steep curve for the "multi- level bitmap" (which is just a fancy way of saying "micro-optimized trie"). A proper trie would result in a logarithmic curve. DES -- Dag-Erling Smørgrav - [EMAIL PROTECTED] _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
