[ntp:questions] Optimising NTP build for Raspberry Pi 2
juergen.perlinger at t-online.de
Sat Mar 7 21:01:02 UTC 2015
On 03/07/2015 01:41 PM, Neil Green wrote:
> In an attempt to squeeze all I can out of a NTP and GPS/PPS setup on the Raspberry Pi 2 I’m starting to experiment with compile flags using GCC 4.8. Currently I have:
> CC="gcc-4.8" CFLAGS="-mcpu=cortex-a7 -mfpu=neon-vfpv4" ./configure --enable-NMEA --enable-ATOM --enable-linuxcaps --disable-all-clocks --disable-parse-clocks --disable-ipv6
> Will attempting to optimise the build like this have any positive impact on NTP in terms of precision, stability etc, or am I focussing on an area that will have no benefit?
Tweaking here can save you code size by omitting features you do not
use, and it might save you execution cycles if the compiler can tailor
the machine code as tight to the target as possible. But NTPD is not
exactly a number crunching application or high volume data server, so
you might end up with a diminishing return of invest.
IMHO the code size reduction is the most prominent potential benefit you
can get. ('Potential' because I do not now how tight your RAM is
crammed.) As others have mentioned, the affect on the operation itself
is probably nonexistent -- the critical execution paths should mostly be
in the kernel.
Oh, and your build time should go down. But I guess that's not what was
foremost in your mind...
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