From e99191d5d4c270b1eb3ed88094e93ae3e818b42a Mon Sep 17 00:00:00 2001 From: Daniel Micay Date: Thu, 4 Oct 2018 03:44:19 -0400 Subject: [PATCH] document tuning vm.max_map_count --- README.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/README.md b/README.md index 8060f1d..974495e 100644 --- a/README.md +++ b/README.md @@ -37,6 +37,12 @@ executables using glibc or musl: ./preload.sh krita --new-image RGBA,U8,500,500 +It can be necessary to substantially increase the `vm.max_map_count` sysctl to +accomodate the large number of mappings caused by guard slabs and large +allocation guard regions. There will be a configuration option in `config.h` +for tuning the proportion of slabs to guard slabs too, since the default 1:1 +proportion makes the address space quite sparse. + It can offer slightly better performance when integrated into the C standard library and there are other opportunities for similar hardening within C standard library and dynamic linker implementations. For example, a library