[lld] r247408 - Add more information to a comment.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Fri Sep 11 08:20:07 2015
New Revision: 247408

URL: http://llvm.org/viewvc/llvm-project?rev=247408&view=rev
Log:
Add more information to a comment.

Modified:
    lld/trunk/ELF/Writer.cpp

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=247408&r1=247407&r2=247408&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Fri Sep 11 08:20:07 2015
@@ -29,8 +29,10 @@ using namespace lld::elf2;
 
 static const int PageSize = 4096;
 
-// On linux x86_64 mmap of the first 15 pages fails, so the smallest value
-// that can be used in here is 0x10000.
+// On freebsd x86_64 the first page cannot be mmaped.
+// On linux that is controled by vm.mmap_min_addr. At least on some x86_64
+// installs that is 65536, so the first 15 pages cannot be used.
+// Given that, the smallest value that can be used in here is 0x10000.
 // If using 2MB pages, the smallest page aligned address that works is
 // 0x200000, but it looks like every OS uses 4k pages for executables.
 // FIXME: This is architecture and OS dependent.