b8823ab026
For small bitmaps, a linear scan of the bitmap is slightly faster than a tree search - bitmap_t is more compact, and there are fewer writes since we don't have to propogate state transitions up the tree. On x86_64 with the current settings, I'm seeing ~.5%-1% CPU improvement in production canaries with this change. The old tree code is left since 32bit sizes are much larger (and ffsl smaller), and maybe the run sizes will change in the future. This resolves #339.
jemalloc is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support. jemalloc first came into use as the FreeBSD libc allocator in 2005, and since then it has found its way into numerous applications that rely on its predictable behavior. In 2010 jemalloc development efforts broadened to include developer support features such as heap profiling, Valgrind integration, and extensive monitoring/tuning hooks. Modern jemalloc releases continue to be integrated back into FreeBSD, and therefore versatility remains critical. Ongoing development efforts trend toward making jemalloc among the best allocators for a broad range of demanding applications, and eliminating/mitigating weaknesses that have practical repercussions for real world applications. The COPYING file contains copyright and licensing information. The INSTALL file contains information on how to configure, build, and install jemalloc. The ChangeLog file contains a brief summary of changes for each release. URL: http://www.canonware.com/jemalloc/