How to change the last level cache replacement policy?

[Jenny]

I have written a file that implements my own cache replacement policy. However, I can find where to change in the base.cfg file to use it in LLC. Do you have any advise about which configure file to change for me?

[Trevor E. Carlson]

Jenny,

The base.cfg configuration file is just a starting point for configuring the machine. By default, when you do not specify a configuration, the gainestown config is brought in (after base.cfg). We try to structure the configuration files to have a hierarchy, where the gainestown.cfg file (platform) includes the nehalem.cfg file (core configuration). In the gainestown.cfg file, you will find the L3 replacement policy configuration settings.

[perf_model/l3_cache]

replacement_policy = lru

You can also specify this on the command line directly. To do this, start with the gainestown configuration, and add the new replacement policy option to replace. For example, you could use your new replacement policy for your L3 cache (assuming that you have already updated sniper/common/core/memory_subsystem/cache/cache_set.cc for the new replacement policy) like this:

~/sniper$ ./run-sniper -cgainestown -gperf_model/l3_cache/replacement_policy=jiazhenpolicy -- /bin/ls

Definitely tell us if you run into any issues or have any other questions,

Trevor

On Mar 12, 2014, at 8:35 AM, Jenny <jia...@umich.edu> wrote:

I have written a file that implements my own cache replacement policy. However, I can find where to change in the base.cfg file to use it in LLC. Do you have any advise about which configure file to change for me?

--
--
--
You received this message because you are subscribed to the Google
Groups "Sniper simulator" group.
To post to this group, send email to snip...@googlegroups.com
To unsubscribe from this group, send email to
snipersim+...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/snipersim?hl=en

---
You received this message because you are subscribed to the Google Groups "Sniper simulator" group.
To unsubscribe from this group and stop receiving emails from it, send an email to snipersim+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Jenny]

Hi Trevor,

Thank you very much for your reply! It helps a lot. I still have one more question. Are the functions for LLC implemention in the files of common/core/memory_subsystem/cache folder? Or in any other places? Thank you very much!

Best wishes,
Jenny

[Wim Heirman]

Jenny,

Functionality of the caches is in a few places, all under sniper/common/core/memory_subsystem:

- cache/cache_set_*.cc are all replacement policies

- parametric_dram_directory_msi/cache_cntlr.cc implements the different cache levels and how they interact, including coherence

- pr_l1_pr_l2_dram_directory_msi/dram_directory_cntlr.cc implements the tag directory side of the directory-based coherence protocol

Let us know if you are looking for anything more specific.

Regards,

Wim

[SWAPNIL BHOSALE]

Hello,

I am trying to implement STTRAM as LLC. The read and write times of STTRAM are very different. The configurations files in sniper for e.g. gainestown has this parameter called 'data access time' which I feel is common for read/write operation. Can somebody please tell me how/which cache files should I modify in order to get read time and write time separately? Because I want to simulate sniper with STTRAM as LLC with different read and write times. 

Thank you in anticipation!