From 9f6a9f4c1f78fd61297e01ae1521af9696d2023b Mon Sep 17 00:00:00 2001 From: Qi Wang Date: Thu, 25 Jul 2019 13:43:59 -0700 Subject: [PATCH] Update manual for opt.retain (new default on Windows). --- doc/jemalloc.xml.in | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/doc/jemalloc.xml.in b/doc/jemalloc.xml.in index e23ccb7f..7fecda7c 100644 --- a/doc/jemalloc.xml.in +++ b/doc/jemalloc.xml.in @@ -963,17 +963,17 @@ mallctl("arena." STRINGIFY(MALLCTL_ARENAS_ALL) ".decay", linkend="stats.retained">stats.retained for related details). It also makes jemalloc use mmap2 - in a more greedy way, mapping larger chunks in one go. - This option is disabled by default unless discarding virtual memory is - known to trigger - platform-specific performance problems, e.g. for [64-bit] Linux, which - has a quirk in its virtual memory allocation algorithm that causes - semi-permanent VM map holes under normal jemalloc operation. Although - munmap - 2 causes issues on 32-bit Linux as - well, retaining virtual memory for 32-bit Linux is disabled by default - due to the practical possibility of address space exhaustion. - + or equivalent in a more greedy way, mapping larger + chunks in one go. This option is disabled by default unless discarding + virtual memory is known to trigger platform-specific performance + problems, namely 1) for [64-bit] Linux, which has a quirk in its virtual + memory allocation algorithm that causes semi-permanent VM map holes + under normal jemalloc operation; and 2) for [64-bit] Windows, which + disallows split / merged regions with + MEM_RELEASE. Although the + same issues may present on 32-bit platforms as well, retaining virtual + memory for 32-bit Linux and Windows is disabled by default due to the + practical possibility of address space exhaustion.