4a0dbb5ac8
Use pairing heap instead of red black tree in arena runs_avail. The extra links are unioned with the bitmap_t, so this change doesn't use any extra memory. Canaries show this change to be a 1% cpu win, and 2% latency win. In particular, large free()s, and small bin frees are now O(1) (barring coalescing). I also tested changing bin->runs to be a pairing heap, but saw a much smaller win, and it would mean increasing the size of arena_run_s by two pointers, so I left that as an rb-tree for now.
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/