Sdbusplus-based Shared Library

[Tanous, Ed]

Have you tried prototyping to see how much space you'll save?  I suspect it won't be a lot for a few reasons.

1. A lot of sdbusplus is template instantiations, and unless we forward declare a number of base template instantiations for use in the shared library, most of the application code will end up in the binary anyway.
2. Sdbus calls into libsystemd, which is already a shared library.
3. The filesystem is already compressed, so I suspect that any duplicated methods that aren't inlined will have the same binary code pattern and get duplicated by the squashfs filesystem.

Those are all the reasons why I haven't really looked into it for the dbus stuff;  I can't speak to the timer stuff, but I suspect the wins in size there are going to be small.

Normal disclaimer, on this specific library, I haven't prototyped anything, just done back of the napkin guesses, so I could very easily be missing something here.

-Ed

> -----Original Message-----
> From: openbmc [mailto:openbmc-
> bounces+ed.tanous=intel.com at lists.ozlabs.org] On Behalf Of Patrick
> Venture
> Sent: Monday, March 19, 2018 10:12 AM
> To: Ratan K Gupta <ratagupt at in.ibm.com>; Brad Bishop
> <bradleyb at fuzziesquirrel.com>; OpenBMC Maillist
> <openbmc at lists.ozlabs.org>
> Subject: Sdbusplus-based Shared Library
> 
> We have a lot of duplication across daemons using sdbusplus, and no new
> utility library.  To avoid every daemon having their own timer object, and
> their own this or that, I suggest we create this shared library.
> 
> Thoughts?  We can start simple, just have a timer object in there, and then
> the new timers being introduced to phosphor-hwmon and phosphor-host-
> ipmid can be the first customers.
> 
> Patrick