diff --git a/readme.md b/readme.md index 4dea1086..00e1c389 100644 --- a/readme.md +++ b/readme.md @@ -80,6 +80,13 @@ Note: the `v2.x` version has a new algorithm for managing internal mimalloc page and fragmentation compared to mimalloc `v1.x` (especially for large workloads). Should otherwise have similar performance (see [below](#performance)); please report if you observe any significant performance regression. +* 2024-04-22, `v1.8.4`, `v2.1.4`: Fixes various bugs and build issues. Improved performance on aligned allocation. + Free-ing code is refactored into a separate module (`free.c`). New approach to collection of abandoned segments: When + a thread terminates the segments it owns are abandoned (containing still live objects) and these can be + reclaimed by other threads. We no longer use a list of abandoned segments but this is now done using bitmaps in arena's + which is more concurrent (and more aggressive). Abandoned memory can now also be reclaimed if a thread frees an object in + an abandoned page (which can be disabled using `mi_option_abandoned_reclaim_on_free`). + * 2023-04-24, `v1.8.2`, `v2.1.2`: Fixes build issues on freeBSD, musl, and C17 (UE 5.1.1). Reduce code size/complexity by removing regions and segment-cache's and only use arenas with improved memory purging -- this may improve memory usage as well for larger services. Renamed options for consistency. Improved Valgrind and ASAN checking. @@ -298,8 +305,9 @@ Further options for large workloads and services: at runtime. Setting `N` to 1 may avoid problems in some virtual environments. Also, setting it to a lower number than the actual NUMA nodes is fine and will only cause threads to potentially allocate more memory across actual NUMA nodes (but this can happen in any case as NUMA local allocation is always a best effort but not guaranteed). -- `MIMALLOC_ALLOW_LARGE_OS_PAGES=1`: use large OS pages (2MiB) when available; for some workloads this can significantly - improve performance. Use `MIMALLOC_VERBOSE` to check if the large OS pages are enabled -- usually one needs +- `MIMALLOC_ALLOW_LARGE_OS_PAGES=1`: use large OS pages (2 or 4MiB) when available; for some workloads this can significantly + improve performance. When this option is disabled it also disables transparent huge pages (THP) for the process + (on Linux and Android). Use `MIMALLOC_VERBOSE` to check if the large OS pages are enabled -- usually one needs to explicitly allow large OS pages (as on [Windows][windows-huge] and [Linux][linux-huge]). However, sometimes the OS is very slow to reserve contiguous physical memory for large OS pages so use with care on systems that can have fragmented memory (for that reason, we generally recommend to use `MIMALLOC_RESERVE_HUGE_OS_PAGES` instead whenever possible).