On 10.07.2018 11:01, Martin Husemann wrote: > On Fri, Jul 06, 2018 at 04:04:50PM +0200, Martin Husemann wrote: >> I have no scientific data yet, but just noticed that build times on the >> auto build cluster did rise very dramatically since it has been updated >> to run NetBSD 8.0 RC2. >> >> Since builds move around build slaves sometimes (not exactly randomly, >> but anyway) I picked the alpha port as an example (the first few >> architectures in the alphabetical list get build slaves assigned pretty >> consistently). > > Here is an intermediate result from further experiments and statistics: > > - fpu_eager (as it is on NetBSD 8.0 RC2, which is not what is in -current > and not what will be in the final 8.0 release) has a measurable performance > impact - but it is not the big issue here. > > - if we ignore netbsd-7* branches, the performance loss is reasonable > explainable by the SVS penalty - we are going to check that theory soon. > > - maybe the netbsd-7 /bin/sh and/or /usr/bin/make cause some very bad > interaction with SVS, making those build times sky rocket - if turning > off SVS does not solve this, we will need to dig deeper. > > So stay tuned, maybe only Intel to blame ;-) > > If anyone has concrete pointers for the last issue (or ideas what to change/ > measure) please speak up. > > Martin > After the switch from NetBSD-HEAD (version from 1 year ago) to 8.0RC2, the ld(1) linker has serious issues with linking Clang/LLVM single libraries within 20 minutes. This causes frequent timeouts on the NetBSD buildbot in the LLVM buildfarm. Timeouts were never observed in the past, today there might be few of them daily. We were experimenting with disabled SVS, but it didn't help. Another observation is that grep(1) on one NetBSD server is significantly slower between the switch from -7 to 8RC1.
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