From a17d9bc6eda9f8c736ab1c5ec4d4dbf3f9218b07 Mon Sep 17 00:00:00 2001 From: David Blaikie Date: Mon, 12 Jun 2017 22:16:49 +0000 Subject: [PATCH] Support: Don't set RLIMIT_AS on child processes when applying a memory limit It doesn't seem relevant to set an address space limit - this isn't important in any sense that I'm aware & it gets in the way of things that use a lot of address space, like llvm-symbolizer. This came up when I realized that bugpoint regression tests were much slower with -gsplit-dwarf than plain -g. Turned out that bugpoint subprocesses (opt, etc) were crashing and doing symbolization - but bugpoint runs those subprocesses with a 400MB memory limit. So with plain -g, mmaping the opt binary would exceed the memory limit, fail, and thus be really fast - no symbolization occurred. Whereas with -gsplit-dwarf, comically, having less to map in, it would succeed and then spend lots of time symbolizing. I've fixed at least the critical part of bugpoint's perf problem there by adding an option to allow bugpoint to disable symbolization. Thus improving the perfromance for -gsplit-dwarf and making the -g-esque speed available without this quirk/accidental benefit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305242 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/Unix/Program.inc | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/lib/Support/Unix/Program.inc b/lib/Support/Unix/Program.inc index 7d3537e2072..2df0eaff47e 100644 --- a/lib/Support/Unix/Program.inc +++ b/lib/Support/Unix/Program.inc @@ -163,16 +163,6 @@ static void SetMemoryLimits (unsigned size) r.rlim_cur = limit; setrlimit (RLIMIT_RSS, &r); #endif -#ifdef RLIMIT_AS // e.g. NetBSD doesn't have it. - // Don't set virtual memory limit if built with any Sanitizer. They need 80Tb - // of virtual memory for shadow memory mapping. -#if !LLVM_MEMORY_SANITIZER_BUILD && !LLVM_ADDRESS_SANITIZER_BUILD - // Virtual memory. - getrlimit (RLIMIT_AS, &r); - r.rlim_cur = limit; - setrlimit (RLIMIT_AS, &r); -#endif -#endif #endif } -- 2.50.1