The recvTimingResp function in the cache handles timing
responses. Over time, recvTimingResp has grown in complexity and code
size. This change factors out some of its functionality to a separate
function. The new function iterates through the in-service targets and
handles them accordingly.
Change-Id: I0ef28288640f6be1b30452b0664d32432e692ea6
Reviewed-on: https://gem5-review.googlesource.com/10423
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
To decide whether we allocate upon receiving a response we need to
determine if any of the currently serviced requests (non-deferred
targets) is comming from another cache. This change adds support for
tracking this information in the MSHR.
Change-Id: If1db93c12b6af5813b91b9d6b6e5e196d327f038
Reviewed-on: https://gem5-review.googlesource.com/10422
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
The tags in the cache keep track of the number of references to the
blocks as well as the average number of references between an
insertion and the next invalidation. Previously the stats where
updated only on block insertion and invalidations were ignored. This
changes moves the update of the counters to the block invalidation
function.
Change-Id: Ie7672c13813ec278a65232694024d2e5e17c4612
Reviewed-on: https://gem5-review.googlesource.com/10428
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
At the moment isTouched is used in the warm-up detection mechanism but
it keeps track of the same information as isValid(). This change
removes it and substitutes its use by isValid().
Change-Id: I611ddf2fa4562ae3b3b2ed2fb74d26abd2e5ec62
Reviewed-on: https://gem5-review.googlesource.com/10427
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
When we use the tempBlock to fill-in, we have to write it back and
invalidate it at the end of current transaction. This patch simplifies
the writeback flow by treating it as a regular writeback.
Change-Id: I257be7bbff211e2832ad001a4e991daf67704485
Reviewed-on: https://gem5-review.googlesource.com/10421
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Create a block insertion function to be used when inserting
blocks. This resets the number of references to 1 (the
insertion is taken into account), sets the insertion tick,
and set secure state.
Change-Id: Ifc34cbbd1c125207ce47912d188809221c7a157e
Reviewed-on: https://gem5-review.googlesource.com/9824
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Implementation of a Second-Chance replacement policy. Similar to FIFO,
but every block is given a second chance if it has been touched.
Change-Id: Id4d52b698d0045a4914a4d848fdf9c3c00a28508
Reviewed-on: https://gem5-review.googlesource.com/9441
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Replacement data is specific for each replacement policy, and thus
should be instantiated differently by each policy.
Touch() and reset() do not need to be aware of CacheBlk, as they
only update its ReplacementData.
Invalidate() makes replacement policies independent of cache blocks,
by removing the awareness of the valid state.
An inheritable base ReplaceableEntry class was created to allow usage
of replacement policies with any table-like structure.
Change-Id: I998917d800fa48504ed95abffa2f1b7bfd68522b
Reviewed-on: https://gem5-review.googlesource.com/9421
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
With this patch a gem5 System will store more info about its Masters.
While it was previously keeping track of the Master name and Master ID
only, it is now adding a per-Master pointer to the SimObject related to
the Master.
This will make it possible for a client to query a System for a Master
using either the master's name or the master's pointer.
Change-Id: I8b97d328a65cd06f329e2cdd3679451c17d2b8f6
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/9781
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Use block iteration instead of numSets and assoc in print(),
cleanupRefs() and computeStats().
This makes these functions rely solely on what they are used for:
printing and calculating stats of blocks. With the addition of
Sectors an extra indirection level is added, and thus these
functions would be skipping blocks.
Change-Id: I0006f82736cce02ba3e501ffafe9236f748daf32
Reviewed-on: https://gem5-review.googlesource.com/10143
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
An access must perform a block search, which is done by findBlock.
The tagHash is indexed by tags, so use extractTag instead of re-
implementing its functionality.
Change-Id: Ib5abacbc65cddf0f2d7e4440eb5355b56998a585
Reviewed-on: https://gem5-review.googlesource.com/10082
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This change fixes a few bugs and refactors the mechanism by which
caches that use the FALRU tags can output statistics for multiple
cache sizes ranging from the minimum cache of interest up to the
actual configured cache size.
Change-Id: Ibea029cf275a8c068c26eceeb06c761fc53aede2
Reviewed-on: https://gem5-review.googlesource.com/9826
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
FALRU was missing MoveToTail functionality within its invalidate
function, and MoveToHead was doing unnecessary passes when the
moved block was the head already.
Besides, added some comments to make the code understandable.
Change-Id: I2430d82b5d53c88b102a62610ea38b46d6e03a55
Reviewed-on: https://gem5-review.googlesource.com/9541
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Block insertion is being done in the getCandidates function, while the
insertBlock function does not do anything.
Besides, BaseTags' stats weren't being updated.
Change-Id: Iadab9c1ea61519214f66fa24c4b91c4fc95604c0
Reviewed-on: https://gem5-review.googlesource.com/8882
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Replacement policies (LRU, Random) are currently considered as array
indexing methods, but have completely different functionalities:
- Array indexers determine the possible locations for block allocation.
This information is used to generate replacement candidates when
conflicts happen.
- Replacement policies determine which of the replacement candidates
should be evicted to make room for new allocations.
For this reason, they were split into different classes. Advantages:
- Easier and more straightforward to implement other replacement
policies (RRIP, LFU, ARC, ...)
- Allow easier future implementation of cache organization schemes
As now we can't assure the use of sets, the previous way to create a
true LRU is not viable. Now a timestamp_bits parameter controls how
many bits are dedicated for the timestamp, and a true LRU can be
achieved through an infinite number of bits (although a few bits suffice
in practice).
Change-Id: I23750db121f1474d17831137e6ff618beb2b3eda
Reviewed-on: https://gem5-review.googlesource.com/8501
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Block allocation can fail when there is an in-service MSHR that
operates on the victim block. This can happed due to:
* an upgrade operation: a request that needs a writable copy of the
block finds a shared (non-writable) copy of the block in the cache
and has allocates an MSHR for the pending upgrade operation, or
* a clean operation: a clean request finds a dirty copy of the block
and allocates an MSHR for the pending clean operation.
This changes relaxes an assertion to allow for the 2nd case (cache
clean operations).
Change-Id: Ib51482160b5f2b3702ed744b0eac2029d34bc9d4
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/9021
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>
invalidate was defined as a separate function in the base associative
and fully-associative tags classes although both functions should
implement identical functionality. This patch moves the invalidate
function in the base tags class.
Change-Id: I206ee969b00ab9e05873c6d87531474fcd712907
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8286
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Writebacks write data to either an existing block or a newly allocated
block. In either case we need to populate the whenReady field of the
block which will determine when the new value can be used.
Change-Id: I5788fad0b8086a1be96714639bf6a9470b334926
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8285
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
The secure bit should be set when we fill a block with data from a
secure location, as indicated by the packet that triggers the fill.
This patch fixes a bug in which the cache wouldn't populate the secure
bit when filling the temp block.
Change-Id: I95c706146449804ff42b205b25dd79750f3e882a
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8284
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
The warmupPercentage is the percentage of different tags (based on the
cache size) that need to be touched in order to warm up the cache.
If Warmup failed (i.e., not enough tags were touched), warmup_cycle = 0.
The warmup is not being taken into account to calculate the stats (i.e.,
stats acquisition starts before cache is warmed up). Maybe in the future
this functionality should be added.
Change-Id: I2b93a99c19fddb99a4c60e6d4293fa355744d05e
Reviewed-on: https://gem5-review.googlesource.com/8061
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
We set the satisfied flag when a cache clean request encounters:
1) a block with the dirty bit set, or
2) a pending modified MSHR which means that the cache will get copy of
the block that will be soon modified.
This changeset fixes a previous bug that set the satisfied flag on
snooping MSHR hits even the pendingModified flags was not set.
Change-Id: I4968c4820997be5cc1238148eea12a1ba39837d4
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7822
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
