[Bug other/50636] GC in large LTO builds cause excessive fragmentation in memory map

["andi-gcc at firstfloor dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50636

--- Comment #11 from Andi Kleen <andi-gcc at firstfloor dot org> 2011-10-08 16:47:54 UTC ---
Created attachment 25445
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25445
patchkit

I tested this patchkit which implements most of the ideas from this bug,
unfortunately still the same problem (with 20% threshold and madvise)

>From the core file I see a lot of 2-3 page holes still:

65218 load65205     00019000  00002ae45c515000  0000000000000000  bfea1000 
2**12
                  CONTENTS, ALLOC, LOAD
65219 load65206     00018000  00002ae45c52f000  0000000000000000  bfeba000 
2**12
                  CONTENTS, ALLOC, LOAD
65220 load65207     00013000  00002ae45c548000  0000000000000000  bfed2000 
2**12
                  CONTENTS, ALLOC, LOAD
65221 load65208     00019000  00002ae45c55d000  0000000000000000  bfee5000 
2**12
                  CONTENTS, ALLOC, LOAD
65222 load65209     00001000  00002ae45c577000  0000000000000000  bfefe000 
2**12
                  CONTENTS, ALLOC, LOAD
65223 load65210     00044000  00002ae45c579000  0000000000000000  bfeff000 
2**12
                  CONTENTS, ALLOC, LOAD
65224 load65211     0003d000  00002ae45c5be000  0000000000000000  bff43000 
2**12
                  CONTENTS, ALLOC, LOAD
65225 load65212     00021000  00002ae45c5fc000  0000000000000000  bff80000 
2**12
                  CONTENTS, ALLOC, LOAD
65226 load65213     00006000  00002ae45c61e000  0000000000000000  bffa1000 
2**12
                  CONTENTS, ALLOC, LOAD
65227 load65214     0002d000  00002ae45c625000  0000000000000000  bffa7000 
2**12
                  CONTENTS, ALLOC, LOAD
65228 load65215     00041000  00002ae45c653000  0000000000000000  bffd4000 
2**12
                  CONTENTS, ALLOC, LOAD
65229 load65216     0000b000  00002ae45c695000  0000000000000000  c0015000 
2**12
                  CONTENTS, ALLOC, LOAD
65230 load65217     00001000  00002ae45c6a1000  0000000000000000  c0020000 
2**12
                  CONTENTS, ALLOC, LOAD
65231 load65218     0000f000  00002ae45c6a3000  0000000000000000  c0021000 
2**12
                  CONTENTS, ALLOC, LOAD
65232 load65219     00001000  00002ae45c6b3000  0000000000000000  c0030000 
2**12
                  CONTENTS, ALLOC, LOAD
65233 load65220     00031000  00002ae45c6b5000  0000000000000000  c0031000 
2**12
                  CONTENTS, ALLOC, LOAD
65234 load65221     0001a000  00002ae45c6e7000  0000000000000000  c0062000 
2**12
                  CONTENTS, ALLOC, LOAD
65235 load65222     0001c000  00002ae45c702000  0000000000000000  c007c000 
2**12
                  CONTENTS, ALLOC, LOAD