(Slightly OT) Telling exactly which objects get promoted

[Jon Masamitsu]

On 04/08/10 03:26, Ben Evans wrote:
>
> Hi,
>
> Apologies if this is too off-topic, or is covered in a document which 
> my Google-Foo has been insufficient to locate so far.
>
> I have an application which is displaying an odd collection pattern on 
> large heaps (3G on a 32-bit 6u18). Broadly, all our objects are 
> sufficiently short-lived that we don't expect any of them to survive 
> to tenure, and yet a small amount of them seem to, so over time we are 
> unable to completely avoid full collections.

Even short lived objects will survive a collection if the collection 
happens right after the
objects are allocated.  Try increasing MaxTenuringThreshold and maybe 
increasing the size
of your survivor space sizes.
>
> We would like some tool or JVM setting which would allow us to see 
> exactly which objects (or failing that, their classes) are reaching 
> tenure. Can anyone suggest something suitable, or some docs?
>
> Thanks,
>
> Ben
> -- 
> Ben Evans
> GFFX Auto Trading
> Deutsche Bank, London
> Office: +44 (0)20 7541 3953
>
> ---
>
> This e-mail may contain confidential and/or privileged information. If 
> you are not the intended recipient (or have received this e-mail in 
> error) please notify the sender immediately and delete this e-mail. 
> Any unauthorized copying, disclosure or distribution of the material 
> in this e-mail is strictly forbidden.
>
> Please refer to http://www.db.com/en/content/eu_disclosures.htm for 
> additional EU corporate and regulatory disclosures.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.openjdk.java.net/pipermail/hotspot-dev/attachments/20100408/4da812fc/attachment.html