Review request: 8013132: Add a flag to turn off the output of the verbose verification code

Bengt Rutisson bengt.rutisson at oracle.com
Thu Apr 25 06:20:04 UTC 2013


Stefan,

Looks good to me.

Bengt


On 4/24/13 8:12 PM, Stefan Karlsson wrote:
> http://cr.openjdk.java.net/~stefank/8013132/webrev.00/
>
> This RFE adds a new flag named VerifySilently, which can be used to 
> turn off the verbose output that the verification code produces. The 
> proposed name has been chosen to match other Verify flags.
>
> From the Bug description:
> ---
> The HotSpot verification code is rather verbose and intrusive. I 
> propose that we add a flag that can be used to turn this output off.
>
> An example of the verification output:
> $ java -XX:+PrintGC -XX:+UnlockDiagnosticVMOptions 
> -XX:+VerifyBeforeExit -XX:+VerifyAfterGC -XX:+VerifyBeforeGC 
> -XX:+UseConcMarkSweepGC -XX:+ExplicitGCInvokesConcurrent -cp 
> /localhome/tests/ HelloSystemGC
>  VerifyBeforeGC:[Verifying threads heap concurrent mark-sweep 
> generation par new generation remset syms strs zone dict cldg 
> metaspace chunks hand C-heap code cache ]
> [GC (System.gc()) 672K->260K(121600K), 0.0060920 secs]
>  VerifyAfterGC:[Verifying threads heap concurrent mark-sweep 
> generation par new generation remset syms strs zone dict cldg 
> metaspace chunks hand C-heap code cache ]
> [Verifying threads heap concurrent mark-sweep generation par new 
> generation remset syms strs zone dict cldg metaspace chunks hand 
> C-heap code cache ]
> [GC (CMS Initial Mark) 260K(121600K), 0.0204040 secs]
> [Verifying threads heap concurrent mark-sweep generation par new 
> generation remset syms strs zone dict cldg metaspace chunks hand 
> C-heap code cache ]
> [Verifying threads heap concurrent mark-sweep generation par new 
> generation remset syms strs zone dict cldg metaspace chunks hand 
> C-heap code cache ]
> [GC (CMS Final Remark) [Verifying CMS Marking... done] 1604K(121600K), 
> 0.1008210 secs]
> [Verifying threads heap concurrent mark-sweep generation par new 
> generation remset syms strs zone dict cldg metaspace chunks hand 
> C-heap code cache ]
>
> And with the proposed flag turned on:
> [GC (System.gc()) 672K->269K(121600K), 0.0050710 secs]
> [GC (CMS Initial Mark) 269K(121600K), 0.0203380 secs]
> [GC (CMS Final Remark) 1613K(121600K), 0.1007210 secs]
> ---
>
> thanks,
> StefanK

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