max_capacity_pp.cc

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#include "mem/cache/tags/partitioning_policies/max_capacity_pp.hh"
 
#include <algorithm>
#include <string>
 
#include "base/logging.hh"
#include "base/trace.hh"
#include "params/MaxCapacityPartitioningPolicy.hh"
 
namespace gem5
{
 
namespace partitioning_policy
{
 
MaxCapacityPartitioningPolicy::MaxCapacityPartitioningPolicy
    (const MaxCapacityPartitioningPolicyParams &params):
    BasePartitioningPolicy(params), cacheSize(params.cache_size),
    blkSize(params.blk_size), partitionIDs(params.partition_ids),
    capacities(params.capacities)
{
    // check if ids and capacities vectors are the same length
    if (this->partitionIDs.size() != this->capacities.size()) {
        fatal("MaxCapacity Partitioning Policy configuration invalid: ids and "
            "capacities arrays are not equal lengths");
    }
 
    // calculate total cache block count to use when creating allocation maps
    const uint64_t total_block_cnt = this->cacheSize / this->blkSize;
 
    // check allocations and create map
    for (auto i = 0; i < this->partitionIDs.size(); i++) {
        const uint64_t partition_id = this->partitionIDs[i];
        const double cap_frac = capacities[i];
 
        // check Capacity Fraction (cap_frac) is actually a fraction in [0,1]
        if (!(cap_frac >= 0 && cap_frac <= 1)) {
            fatal("MaxCapacity Partitioning Policy for PartitionID %d has "
                "Capacity Fraction %f outside of [0,1] range", partition_id,
                cap_frac);
        }
 
        const uint64_t allocated_block_cnt = cap_frac * total_block_cnt;
        partitionIdMaxCapacity.emplace(partition_id, allocated_block_cnt);
 
        DPRINTF(PartitionPolicy, "Configured MaxCapacity Partitioning Policy "
            "for PartitionID: %d to use portion of size %f (%d cache blocks "
            "of %d total)\n", partition_id, cap_frac, allocated_block_cnt,
            total_block_cnt);
 
    }
}
 
void
MaxCapacityPartitioningPolicy::filterByPartition(
    std::vector<ReplaceableEntry *> &entries,
    const uint64_t id) const
{
    if (// No entries to filter
        entries.empty() ||
        // This partition_id is not policed
        partitionIdMaxCapacity.find(id) == partitionIdMaxCapacity.end() ||
        // This partition_id has not yet used the cache
        partitionIdCurCapacity.find(id) == partitionIdCurCapacity.end() ||
        // The partition_id usage is below the maximum
        partitionIdCurCapacity.at(id) < partitionIdMaxCapacity.at(id))
        return;
 
    // Limit reached, restrict allocation only to blocks owned by
    // the Partition ID
    entries.erase(std::remove_if(entries.begin(), entries.end(),
        [id](ReplaceableEntry *entry) {
            CacheBlk *blk = static_cast<CacheBlk *>(entry);
            return blk->getPartitionId() != id;
        }), entries.end());
}
 
void
MaxCapacityPartitioningPolicy::notifyAcquire(const uint64_t partition_id)
{
    // sanity check current allocation does not exceed its configured maximum
    assert(partitionIdCurCapacity[partition_id] <=
        partitionIdMaxCapacity[partition_id]);
 
    partitionIdCurCapacity[partition_id] += 1;
}
 
void
MaxCapacityPartitioningPolicy::notifyRelease(const uint64_t partition_id)
{
    // sanity check current allocation will not cause underflow
    assert(partitionIdCurCapacity[partition_id] > 0);
 
    partitionIdCurCapacity[partition_id] -= 1;
}
 
} // namespace partitioning_policy
 
} // namespace gem5