From 14fbf85380b23efcc19c8479b65336fc7275d90b Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Fri, 29 Oct 2010 13:11:50 +0000 Subject: [PATCH] * Set libgc's initial heap size to 384 MiB to prevent garbage collection in most cases (and therefore its performance overhead). --- src/libmain/shared.cc | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index 440949bd2a..82309544a6 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -353,6 +353,18 @@ int main(int argc, char * * argv) GC_INIT(); GC_oom_fn = oomHandler; + + /* Set the initial heap size to something fairly big (384 MiB) so + that in most cases we don't need to garbage collect at all. + (Collection has a fairly significant overhead, some.) The heap + size can be overriden through libgc's GC_INITIAL_HEAP_SIZE + environment variable. We should probably also provide a + nix.conf setting for this. Note that GC_expand_hp() causes a + lot of virtual, but not physical (resident) memory to be + allocated. This might be a problem on systems that don't + overcommit. */ + if (!getenv("GC_INITIAL_HEAP_SIZE")) + GC_expand_hp(384000000); #endif try {