[codes-ross-users] Too many rollback events

[Nikhil Jain]

I don’t think 10 microsecond is a large lookahead; How big a system are you trying to simulate (as in the network size)? If the system is small, it may be hard to reduce the rollbacks as the #core increase.

Other things that can be tried:
1. nkp option = number of KPs; but default ROSS uses 16, but you can set it to (#total LPs)/(#cores) - i.e. make each LP has its own KP, which will prevent false rollbacks
2. gvt/batch size = you can try a small gvt frequency (like 4/8) and batch size (4/8).

---
Nikhil Jain
Postdoctoral Fellow, Lawrence Livermore National Laboratory
nikhil.jain at acm.org, http://nikhil-jain.github.io/

> On Jun 5, 2017, at 11:57, Jian Peng <jpeng10 at hawk.iit.edu> wrote:
> 
> Hi,
> 
>     My simulation is having too many events rolled back, like 70%. It's still relatively small scale, 16 cores on 4 nodes, using optimistic scheduler.  The result is attached.
> 
>     Any general idea of reducing number of rollback events? I used the max-opt-lookahead option and set it to 10000. Is it still a large number?
> 
>     Thanks!
> <rollback_result_1.png><rollback_result_2.png>_______________________________________________
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