+1; So our CI will also update to use optimisation flags, right? We need to highlight this in upgrade document to our user; I used to meet so strange behaviour after changing -O level.
On Thu, Feb 18, 2016 at 8:51 AM James DeFelice <[email protected]> wrote: > +1 > On Feb 17, 2016 7:24 PM, "Neil Conway" <[email protected]> wrote: > > > Hi folks, > > > > At present, Mesos defaults to compiling with "-O0"; to enable compiler > > optimizations, the user needs to specify "--enable-optimize". > > > > I'd like to propose we change the default, for a few reasons: > > > > (1) The autoconf default for CFLAGS/CXXFLAGS is "-O2 -g". Anecdotally, > > I think most software packages compile with a reasonable level of > > optimizations enabled by default. > > > > (2) I think we should make the default configure flags appropriate for > > end-users (rather than Mesos developers): developers will be familiar > > enough with Mesos to tune the configure flags according to their own > > preferences. > > > > (3) The performance consequences of not enabling compiler > > optimizations can be pretty severe: 5x in a benchmark I just ran, and > > we've seen between 2x and 30x (!) performance differences for some > > real-world workloads. > > > > Neil > > > -- Regards, ---- Da (Klaus), Ma (马达), PMP® | Advisory Software Engineer IBM Platform Development & Support, STG, IBM GCG +86-10-8245 4084 | [email protected] | http://k82.me
