[Pkg-samba-maint] Profiling support in 2:4.16.1+dfsg-5

[Andreas Hasenack]

Hi,

I see profiling support was enabled, and was wondering if there is any
fear this might introduce performance regressions. I didn't find much
about it, just some data[1] from ancient samba 2.2.1 when it was first
introduced, which said:

"""
With samba compiled for profile data collection, you may see
a very slight degradation in performance even with profiling
collection turned off. On initial tests with NetBench on an
SGI Origin 200 server, this degradation was not measureable
with profile collection off compared to no profile collection
compiled into samba.

With count profile collection enabled on all clients, the
degradation was less than 2%. With full profile collection
enabled on all clients, the degradation was about 8.5%.
"""

And later in samba 4.3.0[2]:
"""
New SMB profiling code
----------------------

The code for SMB (SMB1, SMB2 and SMB3) profiling uses a tdb instead
of sysv IPC shared memory. This avoids performance problems and NUMA
effects. The profile stats are a bit more detailed than before.
"""

Ubuntu has this request[3] to enable profiling, basically giving the
same data as the 2.2.1 samba release notes regarding performance
impact.

If I understand this correctly, the performance impact back then at
least was negligible if profiling was not enabled in the config, but
that was a very old (by now) samba version and hardware. Does anybody
have a more current experience with this?


1. https://www.samba.org/samba/history/samba-2.2.1.html
2. https://www.samba.org/samba/history/samba-4.3.0.html
3. https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1846947/comments/3