RFR(XS): JDK-8144837: Improve the printout of heap regions in hs_err dump files.

[Stefan Karlsson]

Hi David,

On 2015-12-09 10:12, David Lindholm wrote:
> Hi,
>
> Please review the following patch that changes the format for the heap 
> region printouts in hs_err files and when running with 
> -XX:+PrintHeapAtGCExtended
>
> The old format looked like this:
>
> AC   0  F    TS     5 PTAMS 0x00000005cbc00000 NTAMS 
> 0x00000005cbc00000 space 2048K,   0% used [0x00000005cbc00000, 
> 0x00000005cbe00000)
> AC   0  S CS TS     7 PTAMS 0x00000005cbe00000 NTAMS 
> 0x00000005cbe00000 space 2048K, 100% used [0x00000005cbe00000, 
> 0x00000005cc000000)
> AC   0  F    TS     5 PTAMS 0x00000005cc000000 NTAMS 
> 0x00000005cc000000 space 2048K,   0% used [0x00000005cc000000, 
> 0x00000005cc200000)
>
> The new format looks like this:
>
> [  21][0x00000005cd000000, 0x00000005cd000000, 0x00000005cd200000][  
> 0%][ F][  ][TS  7][AC  0][TAMS 0x00000005cd000000, 0x00000005cd000000]
> [  22][0x00000005cd200000, 0x00000005cd400000, 
> 0x00000005cd400000][100%][ S][CS][TS  9][AC  0][TAMS 
> 0x00000005cd200000, 0x00000005cd200000]
> [  23][0x00000005cd400000, 0x00000005cd600000, 
> 0x00000005cd600000][100%][ S][CS][TS  9][AC  0][TAMS 
> 0x00000005cd400000, 0x00000005cd400000]

Could we use pipes instead of the square brackets. Too me that reduces 
the clutter a bit:
|  21|0x00000005cd000000, 0x00000005cd000000, 0x00000005cd200000|  0%| 
F|  |TS  7|AC  0|TAMS 0x00000005cd000000, 0x00000005cd000000|
|  22|0x00000005cd200000, 0x00000005cd400000, 0x00000005cd400000|100%| 
S|CS|TS  9|AC  0|TAMS 0x00000005cd200000, 0x00000005cd200000|
|  23|0x00000005cd400000, 0x00000005cd600000, 0x00000005cd600000|100%| 
S|CS|TS  9|AC  0|TAMS 0x00000005cd400000, 0x00000005cd400000|

Thanks,
StefanK

>
> The first number is the index, and for each heap region we print 
> bottom, top and end.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8144837
> Webrev: http://cr.openjdk.java.net/~david/JDK-8144837/webrev.00/
>
>
> Thanks,
> David