Can a full codecache trigger CMS? (was: Erratic(?) CMS behaviour every 5d)

[Damon Hart-Davis]

Hi,

Have you tried -XX:+UseCodeCacheFlushing to let old code get evicted in case that helps?

Rgds

Damon


On 5 Oct 2012, at 17:27, Bernd Eckenfels wrote:

> Hello,
> 
> my problem continues, this time after 7d the erratic behaviour started.  
> This time I was very closely monitoring the system, and the PermGen seems  
> not to be the cause:
> 
> Pool: CMS Perm Gen (Non-heap memory)
> Peak Usage : init:104857600, used:279972328, committed:314572800,  
> max:314572800
> Current Usage : init:104857600, used:216017192, committed:314572800,  
> max:314572800
> 
> What I do see however is, that the code cache slowly approaches the  
> maximum, could that trigger repeating CMS intervalls?
> 
> Pool: Code Cache (Non-heap memory)
> Peak Usage : init:2555904, used:49850048, committed:50266112, max:50331648
> Current Usage : init:2555904, used:49850048, committed:50266112,  
> max:50331648
> 
> This time I will restart the system with OccupancyOnly setting (to 10%). I  
> also increase the CodeCache and enable swweping in it. The PermGen will  
> also be 1G max, just to be sure.
> 
> Here is the current log with CMSStatiscs=2 (which does not help I think).
> https://mft.seeburger.de/portal-seefx/~public/52caa5cc-dfb6-41db-a096-d4f4eb6aba1b?download
> 
> 
> Here is the rest of the memory pools, not that oldgen is at 5%, so  
> unlikely cause for concurrent mode failures.
> 
> Memory Information
> Total Memory Pools: 5
> 
> 
> Pool: Par Eden Space (Heap memory)
> Peak Usage : init:13743947776, used:13743947776, committed:13743947776,  
> max:13743947776
> Current Usage : init:13743947776, used:723224384, committed:13743947776,  
> max:13743947776
> 
> Pool: Par Survivor Space (Heap memory)
> Peak Usage : init:1717960704, used:1693771776, committed:1717960704,  
> max:1717960704
> Current Usage : init:1717960704, used:227068920, committed:1717960704,  
> max:1717960704
> 
> Pool: CMS Old Gen (Heap memory)
> Peak Usage : init:34359738368, used:3018247512, committed:34359738368,  
> max:34359738368
> Current Usage : init:34359738368, used:1787484240, committed:34359738368,  
> max:34359738368
> 
> Greetings
> Bernd
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