num_sets in cache_replacement_policy

[Artem Kulikov]

As I know, cache_size = line_size * associativity * num_sets. However, in the constructor for cache_replacement_policy_t, the number of sets is passed in as ache_size / cache_associativity. The tags and block IDs are calculated correctly, so access should be safe. The replacement_policy_test  covers only the policy itself, not the inner structure.

Could this be a bug, or have I misunderstood something?

[Derek Bruening]

This replacement policy was a recent refactoring. The size/assoc for TLB looks correct.  But at a glance, the cache ones using size/line_size look incorrect: I filed https://github.com/DynamoRIO/dynamorio/issues/7672 and notified the author.

On Wed, Oct 8, 2025 at 3:57 PM Artem Kulikov <kulikov...@gmail.com> wrote:

As I know, cache_size = line_size * associativity * num_sets. However, in the constructor for cache_replacement_policy_t, the number of sets is passed in as ache_size / cache_associativity. The tags and block IDs are calculated correctly, so access should be safe. The replacement_policy_test  covers only the policy itself, not the inner structure.

Could this be a bug, or have I misunderstood something?

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