RFC: system-wide default tunables

[Zack Weinberg]

On Tue, Oct 17, 2023, at 10:10 AM, Adhemerval Zanella Netto wrote:
> On 06/10/23 17:25, DJ Delorie wrote:
>> Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> writes:
>>> The hwcap-related are still used for library selection, the original
>>> intention of the ld.so.cache.  What I am afraid is ld.so.cache start to
>>> being an umbrella for different and unrelated settings.
>> 
>> The alternative is to add an /etc/tunables.cache which would correspond
>> to /etc/tunables.conf and/or /etc/tunables.conf.d/*
>> 
>> On most systems (no files) that would add one unsuccessful stat() call.
>
> We can use 'access' to check for file existent first and then read the whole
> file, as we do for /etc/ld.so.preload.  It should slight faster than stat.  

Even better to open() unconditionally and ignore ENOENT failures.

zw