memory slop

[Tim Docker]

On 14/04/2011, at 6:24 PM, Simon Marlow wrote:

>
> I made some changes to the storage manager in the runtime today, and  
> fixed the slop problem with your program.  Here it is after the  
> changes:
>
>  14,928,031,040 bytes allocated in the heap
>     313,542,200 bytes copied during GC
>      18,044,096 bytes maximum residency (7 sample(s))
>         294,256 bytes maximum slop
>              37 MB total memory in use (0 MB lost due to  
> fragmentation)
>
>  INIT    time    0.00s  (  0.00s elapsed)
>  MUT     time    6.38s  (  6.39s elapsed)
>  GC      time    1.26s  (  1.26s elapsed)
>  EXIT    time    0.00s  (  0.00s elapsed)
>  Total   time    7.64s  (  7.64s elapsed)
>
> I think this is with a different workload than the one you used  
> above. Before the change I was getting
>
>  15,652,646,680 bytes allocated in the heap
>     312,402,760 bytes copied during GC
>      17,913,816 bytes maximum residency (9 sample(s))
>     111,424,792 bytes maximum slop
>             142 MB total memory in use (0 MB lost due to  
> fragmentation)
>
>  INIT  time    0.00s  (  0.00s elapsed)
>  MUT   time    8.01s  (  8.02s elapsed)
>  GC    time   16.86s  ( 16.89s elapsed)
>  EXIT  time    0.00s  (  0.00s elapsed)
>  Total time   24.88s  ( 24.91s elapsed)
>
> (GHC 7.0.3 on x86-64/Linux)  So, a pretty dramatic improvement.  I'm  
> validating the patch right now, it should be in 7.2.1.
>

This looks really promising. Let me know when the patch is available,  
and I'll try it out on my real code.

Thanks,

Tim