Sadly, none of the suggestions on this thread worked. But here is some more detail:
- During stage-1, my machine's CPU is maxed out (or nearly so) in user mode. - After stage-1 (most obviously during rts_dist_HC), my machine spends roughly 80% of its CPU in *system* mode. - Testing on my other machine (which is slower, but much faster at building GHC), I never see high *system* percentages. - Both machines use APFS, which was one candidate for the slowdown. - The slow machine uses XCode 10.1; the fast one uses XCode 9.4.1 - The slow machine uses clang 10.0.0; the fast one uses clang 9.1.0 - `brew install gmp` on the slow machine tells me that gmp is already installed. - As a reminder: the slow machine is macOS 10.13.6; the fast one is macOS 10.13.5. I don't wish to try upgrading the fast one... lest that slow it down! Does anyone have any insight? Thanks! Richard > On Oct 30, 2018, at 2:32 PM, Gabor Greif <[email protected]> wrote: > > Maybe a symptom of an AFPS bug? > https://gregoryszorc.com/blog/2018/10/29/global-kernel-locks-in-apfs/ > > Just came across this, might be worth a look. > > Cheers, > > Gabor > > On 10/26/18, Richard Eisenberg <[email protected]> wrote: >> Hi devs, >> >> I have a shiny, new iMac in my office. It's thus frustrating that it takes >> my iMac longer to build GHC than my trusty 28-month-old laptop. Building >> devel2 on a fresh checkout takes just about an hour. By contrast, my laptop >> is done after 30 minutes of work (same build settings). The laptop has a >> 2.8GHz Intel i7 running macOS 10.13.5; the desktop has a 3.5GHz Intel i5 >> running macOS 10.13.6. Both bootstrapped from the binary distro of GHC >> 8.6.1. >> >> Watching GHC build, everything is snappy enough during the stage-1 build. >> But then, as soon as we start using GHC-produced executables, things slow >> down. It's most noticeable in the rts_dist_HC phase, which crawls. Stage 2 >> is pretty slow, too. >> >> So: is there anything anyone knows about recent Macs not liking locally >> built executables? Or is there some local setting that I need to update? The >> prepackaged GHC seems to work well, so that gives me hope that someone knows >> what setting to tweak. >> >> Thanks! >> Richard >> _______________________________________________ >> ghc-devs mailing list >> [email protected] >> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >> _______________________________________________ ghc-devs mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
