Hi Han-Wen, Great to see you back here!
Han-Wen Nienhuys <hanw...@gmail.com> skribis: > On Tue, Jan 28, 2020 at 11:41 PM Han-Wen Nienhuys <hanw...@gmail.com> wrote: >> Unfortunately, it looks like the adoption of the BDW GC library caused >> a ~6x slowdown, causing an overall end-to-end slowdown of 50%. >> >> I was wondering if you folks would have tips to further tune GC for >> wall-time speed, and if there additional diagnostics to see if we're >> doing something extraordinarily silly. > > For the record, I managed to solve this, by scaling up the heap more > aggressively. See > https://codereview.appspot.com/561390043/diff/557260051/lily/score-engraver.cc Weird. It would be interesting to see where the slowdown comes from. Overall, my recollection of the 1.8 to 2.0 transition (where we introduced libgc) is that GC was a bit faster, definitely not slower. That said, does LilyPond happen to use lots of bignums and/or lots of finalizers? Finalizers, including those on bignums, end up being very GC-intensive, as discussed in my recent message. Perhaps that’s what’s happening here, for instance if you create lots of SMOBs with a free function. Thanks, Ludo’.
