Hi, Please have codereview for
8042243: Map shared archive to preallocated static address
webrev: http://cr.openjdk.java.net/~minqi/8042243/webrev00/
bug: https://bugs.openjdk.java.net/browse/JDK-8042243
Summary: Mapping shared archive (jsa) some time fail due to ASLR
(Address space layout randomization) on 32bit Linux platforms. To solve
we come up with mapping shared archive to preallocated static space
since with Linux and the GCC compiler, the BSS section in the main
executable is not randomized, instead, the variable address in the BSS
section is fixed at build time. The tests also showed the extra 32M
space will NOT affect java memory setting though it seems 32M virtual
address space always allocated no matter it is used or not (If
-XX:ShareBaseAddress supply alternative address for dumping, the static
address will be ignored.) Note the changes is for 32 bit Linux only.
Tests: JPRT, manual test for archive sharing.
Thanks
Yumin
