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refactor: tag array cache index
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@romnn
romnn committed Sep 5, 2023
1 parent a996c39 commit 6b25c1a
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Showing 3 changed files with 156 additions and 82 deletions.
44 changes: 25 additions & 19 deletions src/cache/data.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,9 +89,10 @@ impl Data
);

// update LRU state
let tag_array::AccessStatus { index, .. } =
let tag_array::AccessStatus { cache_index, .. } =
self.inner.tag_array.access(block_addr, fetch, time);
let cache_index = index.unwrap();
let cache_index = cache_index.expect("write hit write back");

let block = self.inner.tag_array.get_block_mut(cache_index);
let was_modified_before = block.is_modified();
block.set_status(cache::block::Status::MODIFIED, &fetch.access.sector_mask);
Expand Down Expand Up @@ -129,28 +130,26 @@ impl Data
fn read_hit(
&mut self,
addr: address,
_cache_index: Option<usize>,
// cache_index: usize,
// _cache_index: Option<usize>,
fetch: &mem_fetch::MemFetch,
time: u64,
_events: &mut [cache::event::Event],
_probe_status: cache::RequestStatus,
// _probe_status: cache::RequestStatus,
) -> cache::RequestStatus {
let super::base::Base {
ref mut tag_array,
// ref cache_config,
ref addr_translation,
..
} = self.inner;
let block_addr = addr_translation.block_addr(addr);
let access_status = tag_array.access(block_addr, fetch, time);
let block_index = access_status.index.expect("read hit has index");
let cache_index = access_status.cache_index.expect("read hit has cache index");

// Atomics treated as global read/write requests:
// Perform read, mark line as MODIFIED
if fetch.is_atomic() {
debug_assert_eq!(*fetch.access_kind(), AccessKind::GLOBAL_ACC_R);
let block = tag_array.get_block_mut(block_index);
let block = tag_array.get_block_mut(cache_index);
let was_modified_before = block.is_modified();
block.set_status(cache::block::Status::MODIFIED, &fetch.access.sector_mask);
block.set_byte_mask(&fetch.access.byte_mask);
Expand Down Expand Up @@ -554,9 +553,10 @@ impl Data
fn process_tag_probe(
&mut self,
is_write: bool,
probe_status: cache::RequestStatus,
probe: Option<(usize, cache::RequestStatus)>,
// probe_status: cache::RequestStatus,
// cache_index: Option<usize>,
addr: address,
cache_index: Option<usize>,
fetch: mem_fetch::MemFetch,
events: &mut Vec<cache::Event>,
time: u64,
Expand All @@ -568,6 +568,11 @@ impl Data
//
// Function pointers were used to avoid many long conditional
// branches resulting from many cache configuration options.
let probe_status = probe
.map(|(_, s)| s)
.unwrap_or(cache::RequestStatus::RESERVATION_FAIL);
let cache_index = probe.map(|(i, _)| i);

let mut access_status = probe_status;
let data_size = fetch.data_size();

Expand Down Expand Up @@ -596,7 +601,8 @@ impl Data
);
}
} else if probe_status == cache::RequestStatus::HIT {
access_status = self.read_hit(addr, cache_index, &fetch, time, events, probe_status);
// access_status = self.read_hit(addr, cache_index, &fetch, time, events, probe_status);
access_status = self.read_hit(addr, &fetch, time, events);
} else if probe_status != cache::RequestStatus::RESERVATION_FAIL {
access_status = self.read_miss(addr, cache_index, &fetch, time, events, probe_status);
} else {
Expand Down Expand Up @@ -669,20 +675,20 @@ impl cache::Cache for Data

let dbg_fetch = fetch.clone();

let (cache_index, probe_status) = self
// let (cache_index, probe_status) = self
let probe = self
.inner
.tag_array
.probe(block_addr, &fetch, is_write, true);
let probe_status = probe
.map(|(_, s)| s)
.unwrap_or(cache::RequestStatus::RESERVATION_FAIL);
// dbg!((cache_index, probe_status));

let access_status = self.process_tag_probe(
is_write,
probe_status,
addr,
cache_index,
fetch,
events,
time,
is_write, probe, // probe_status,
// cache_index,
addr, fetch, events, time,
);
// dbg!(&access_status);

Expand Down
113 changes: 81 additions & 32 deletions src/cache/readonly.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -106,8 +106,6 @@ impl cache::Cache for ReadOnly
events: &mut Vec<cache::Event>,
time: u64,
) -> cache::RequestStatus {
use cache::RequestStatus as Status;

let cache::base::Base {
ref cache_config,
ref addr_translation,
Expand All @@ -132,48 +130,99 @@ impl cache::Cache for ReadOnly
);

let is_probe = false;
let (cache_index, probe_status) =
tag_array.probe(block_addr, &fetch, fetch.is_write(), is_probe);
let mut status = Status::RESERVATION_FAIL;
// let (cache_index, probe_status) =
// tag_array.probe(block_addr, &fetch, fetch.is_write(), is_probe);

let probe = tag_array.probe(block_addr, &fetch, fetch.is_write(), is_probe);
let probe_status = probe
.map(|(_, status)| status)
.unwrap_or(cache::RequestStatus::RESERVATION_FAIL);

if probe_status == Status::HIT {
// update LRU state
tag_array::AccessStatus { status, .. } = tag_array.access(block_addr, &fetch, time);
} else if probe_status != Status::RESERVATION_FAIL {
if self.inner.miss_queue_full() {
status = Status::RESERVATION_FAIL;
let mut status = cache::RequestStatus::RESERVATION_FAIL;

match probe {
None => {
self.inner.stats.lock().inc(
*fetch.access_kind(),
cache::AccessStat::ReservationFailure(
cache::ReservationFailure::MISS_QUEUE_FULL,
cache::ReservationFailure::LINE_ALLOC_FAIL,
),
1,
);
} else {
let (should_miss, _writeback, _evicted) = self.inner.send_read_request(
addr,
block_addr,
cache_index.unwrap(),
fetch.clone(),
time,
events,
true,
false,
);
if should_miss {
status = Status::MISS;
}
Some((_, cache::RequestStatus::HIT)) => {
// update LRU state
tag_array::AccessStatus { status, .. } = tag_array.access(block_addr, &fetch, time);
}
Some((cache_index, probe_status)) => {
if self.inner.miss_queue_full() {
status = cache::RequestStatus::RESERVATION_FAIL;

self.inner.stats.lock().inc(
*fetch.access_kind(),
cache::AccessStat::ReservationFailure(
cache::ReservationFailure::MISS_QUEUE_FULL,
),
1,
);
} else {
status = Status::RESERVATION_FAIL;
let (should_miss, _writeback, _evicted) = self.inner.send_read_request(
addr,
block_addr,
cache_index,
fetch.clone(),
time,
events,
true,
false,
);
if should_miss {
status = cache::RequestStatus::MISS;
} else {
status = cache::RequestStatus::RESERVATION_FAIL;
}
}
}
} else {
self.inner.stats.lock().inc(
*fetch.access_kind(),
cache::AccessStat::ReservationFailure(cache::ReservationFailure::LINE_ALLOC_FAIL),
1,
);
}

// if probe_status == Status::HIT {
// // update LRU state
// tag_array::AccessStatus { status, .. } = tag_array.access(block_addr, &fetch, time);
// } else if probe_status != Status::RESERVATION_FAIL {
// if self.inner.miss_queue_full() {
// status = Status::RESERVATION_FAIL;
//
// self.inner.stats.lock().inc(
// *fetch.access_kind(),
// cache::AccessStat::ReservationFailure(
// cache::ReservationFailure::MISS_QUEUE_FULL,
// ),
// 1,
// );
// } else {
// let (should_miss, _writeback, _evicted) = self.inner.send_read_request(
// addr,
// block_addr,
// cache_index.unwrap(),
// fetch.clone(),
// time,
// events,
// true,
// false,
// );
// if should_miss {
// status = Status::MISS;
// } else {
// status = Status::RESERVATION_FAIL;
// }
// }
// } else {
// self.inner.stats.lock().inc(
// *fetch.access_kind(),
// cache::AccessStat::ReservationFailure(cache::ReservationFailure::LINE_ALLOC_FAIL),
// 1,
// );
// }
self.inner.stats.lock().inc(
*fetch.access_kind(),
cache::AccessStat::Status(select_status(probe_status, status)),
Expand Down
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