Re: [PATCH v2 0/3] System-wide tunables

[DJ Delorie <dj@redhat.com>]

Szabolcs Nagy <szabolcs.nagy@arm.com> writes:
> tunables can differ across targets, so they need to be checked not to
> cause trouble (e.g. doing a hwcap mask specified by an int instead of
> arch feature can do different things across abis)

This is no different than setting an environment variable today, right?
The data stored in ld.so.cache has pre-computed IDs but also the string
names, and the IDs are validated and recomputed in case libc.so changes.
The value string is not parsed unless it's a generic "double" type, and
even then, the string value is still included.

I have not yet implemented any filters for the tunables, but it's
already been requested to have an only/exclude filter for "per program
image name".  I suppose I could add a filter for only/exclude hwcaps
too.

Hmm... aren't tunables processed in ld.so, not libc.so  If so, it's
*already* more difficult to support multiple glibcs at the same time
(tunables mismatch between ld.so and libc.so), unless you have a
separate filesystem namespace, in which case you have a separate
ld.so.cache also.