d227440524
* Fix a race in chunk_dealloc_dss(). * Check for allocation failure before zeroing memory in base_calloc(). Merge enhancements from a divergent version of jemalloc: * Convert thread-specific caching from magazines to an algorithm that is more tunable, and implement incremental GC. * Add support for medium size classes, [4KiB..32KiB], 2KiB apart by default. * Add dirty page tracking for pages within active small/medium object runs. This allows malloc to track precisely which pages are in active use, which makes dirty page purging more effective. * Base maximum dirty page count on proportion of active memory. * Use optional zeroing in arena_chunk_alloc() to avoid needless zeroing of chunks. This is useful in the context of DSS allocation, since a long-lived application may commonly recycle chunks. * Increase the default chunk size from 1MiB to 4MiB. Remove feature: * Remove the dynamic rebalancing code, since thread caching reduces its utility.