Segmentation fault with NUMA aware ParallelScavange GC

Lokesh Gidra lokesh.gidra at
Fri Jul 29 07:25:04 UTC 2011

>The only thing I can think of is that we started using 
>madvise(MADV_FREE) to uncommit pages in lgrp chunks instead of doing 
>mmap over mmap. I've tested it with earlier kernels and it works fine. 
>It could be the semantics of MADV_FREE somehow changed. jdk6u25 has 
>still the hotspot that would do mmap. So running it would confirm the 
But isn't madvise(MADV_FREE) just frees the pages rather than removing the vma region all together? 

Can you please tell me which kernel version did it work fine with? I tried with 6b20 and its still the same. I will try with jdk6u25 as well and let you know.

>Alternatively, if you're open to building hotspot, I can send you a 
>patch to try.

Yes, I am. Please send me the patch.


More information about the hotspot-gc-dev mailing list