Sdbusplus-based Shared Library

[Patrick Venture]

On Mon, Mar 19, 2018 at 11:24 AM, Tanous, Ed <ed.tanous at intel.com> wrote:
> 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.
>

So my thinking wasn't about reducing size of the binary but rather
reducing the toil of maintaining multiple implementations of the same
code.

> -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