ARM: Fix incremental GC

[Xerxes Rånby]

2012-02-20 13:08, Andrew Haley skrev:
> It was reported that ARM crashes with -Xincgc.  It turns out that
> incremental mode is incompatible with the use of the shared Eden
> space, and we weren't checking for that.
> 
> OK for trunk and 1.11 branch?
> 
> While I was debugging this I noticed that thread-local allocation is
> turned off.  I don't know why this is: it ought to bring a substantial
> improvement.  I think there may be several flags in the ARM port that
> could easily be tweaked to provide substantial performance benefits.
> However, before the defaults are changed we'd have to do some testing.
> 
> Andrew.
> 
> 
> 2012-02-20  Andrew Haley  <aph at redhat.com>
> 
> 	* arm_port/hotspot/src/cpu/zero/vm/asm_helper.cpp (Helper_new):
> 	Don't use shared Eden in incremental mode.
> 
> diff -r a5c946d5f4bc -r 82c6fb23eed5 arm_port/hotspot/src/cpu/zero/vm/asm_helper.cpp
> --- a/arm_port/hotspot/src/cpu/zero/vm/asm_helper.cpp	Tue Jan 31 12:36:36 2012 +0000
> +++ b/arm_port/hotspot/src/cpu/zero/vm/asm_helper.cpp	Mon Feb 20 12:02:21 2012 +0000
> @@ -141,7 +141,7 @@
>  	if (UseTLAB) {
>  	  result = (oop) thread->tlab().allocate(obj_size);
>  	}
> -	if (result == NULL) {
> +	if (result == NULL && !CMSIncrementalMode) {
>  	  need_zero = true;
>  	  // Try allocate in shared eden
>      retry:
> 
> 

OK!
Thank you for locating the cause and creating a FIX for this bug.
I think this bug are the same as: http://icedtea.classpath.org/bugzilla/show_bug.cgi?id=584

Please commit to HEAD and 1.1 release branch.
Xerxes