[PATCH] manual: Add stability warning regarding system-wide tunables

Andreas K. Huettel dilfridge@gentoo.org
Mon Jul 20 14:20:32 GMT 2026


Am Montag, 20. Juli 2026, 22:53:56 Japanische Normalzeit schrieb Florian Weimer:
> And mention system-wide tunables in NEWS.
> 

Works for me. Please push it and I'll rebase and resend the remaining changes.
Thanks! -a

Reviewed-by: Andreas K. Hüttel <dilfridge@gentoo.org>

> ---
>  NEWS                 | 5 +++++
>  manual/tunables.texi | 8 +++++++-
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/NEWS b/NEWS
> index e30b7a5f76..c161a3f5b0 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -9,6 +9,11 @@ Version 2.44
>  
>  Major new features:
>  
> +* System-wide tunables can be applied using /etc/tunables.conf and
> +  running ldconfig.  Specific tunable settings and the
> +  /etc/tunables.conf file format and path are not part of the stable
> +  library interfaces and may change between releases.
> +
>  * A new tunable, glibc.elf.thp, is added to map read-only segments with
>    Transparent Huge Pages (THP) if THP isn't disable in kernel.  When
>    glibc.elf.thp is set to 1, malloc uses the actual kernel THP mode
> diff --git a/manual/tunables.texi b/manual/tunables.texi
> index e7dcef1040..b53cfbf4be 100644
> --- a/manual/tunables.texi
> +++ b/manual/tunables.texi
> @@ -92,7 +92,13 @@ In addition to setting the @code{GLIBC_TUNABLES} environment variable,
>  tunables may be provided globally via the file
>  @file{/etc/tunables.conf}, which gets stored in glibc's dynamic
>  library cache @file{/etc/ld.so.cache} and read by every program at
> -startup.  @file{/etc/tunables.conf} contains one tunable per line:
> +startup.
> +
> +@strong{Portability Note:} Specific tunable settings and the
> +@file{/etc/tunables.conf} file format and path are not part of the
> +stable library interfaces and may change between releases.
> +
> +The file @file{/etc/tunables.conf} contains one tunable per line:
>  
>  @example
>  glibc.malloc.trim_threshold=128
> 
> base-commit: 249639137ed360d1827d9e663261ba26d2b01d81
> 
> 


-- 
PD Dr. Andreas K. Hüttel
dilfridge@gentoo.org
Gentoo Linux developer 
(council, comrel, toolchain, base-system, perl, libreoffice)
https://wiki.gentoo.org/wiki/User:Dilfridge
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