Adding back some changes done in patch 676ae57827.
Transient state IS_I, STALE_DATA, Data_Stale event are necessary.
Issue: (cacheline A, initial state for P0 and P1 is I)
| P0 | P1 |
|GETX (A)| |
| |GETS (A)|
|Inv_All | |
P1 never sends the ACK - deadlock
It should ACK, later upon data use it as stale data, and got to I.
Solution:
P1(A):
GETS: I->IS
Inv_All: IS->IS_I, Send ACK
Data: IS_I->I, STALE_DATA to L0
Signed-off-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Change-Id: I1e7b2c05439d08579c68d8eb444e0f332e75e07f
Reviewed-on: https://gem5-review.googlesource.com/c/15715
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This implementation is based in the description available in:
Jinchun Kim, Seth H. Pugsley, Paul V. Gratz, A. L. Narasimha Reddy,
Chris Wilkerson, and Zeshan Chishti. 2016.
Path confidence based lookahead prefetching.
In The 49th Annual IEEE/ACM International Symposium on Microarchitecture
(MICRO-49). IEEE Press, Piscataway, NJ, USA, Article 60, 12 pages.
Change-Id: I4b8b54efef48ced7044bd535de9a69bca68d47d9
Reviewed-on: https://gem5-review.googlesource.com/c/14819
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
A packet queue keeps track of packets that are scheduled to be sent at
a specified time. Packets are sorted such that the packet with the
earliest scheduled time is at the front of the list (unless there are
other ordering requirements). Previouly, the implemented algorithm
didn't allow packets to be placed at the front of the queue resulting
in uneccessary delays. This change fixes the implementation of
schedSendTiming.
Change-Id: Ic74abec7c3f4c12dbf67b5ab26a8d4232e18e19e
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15556
Reviewed-by: Bradley Wang <radwang@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
A packet queue is typically used to hold on to packets that are
schedules to be sent in the future or when they need to queue behind
younger packets that have been sent out yet. Due to memory order
requirements, some MemObjects need to maintain the order for packet
(mostly responses) that reference the same cache block.
Prior to this patch the ordering requirements where determined when
the packet was scheduled to be sent. This patch moves the parameter to
the constructor.
Change-Id: Ieb4d94e86bc7514f5036b313ec23ea47dd653164
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15555
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Implementation of the Access Map Pattern Matching prefetcher
Based in the description of the following paper:
Access map pattern matching for high performance data cache prefetch.
Ishii, Y., Inaba, M., & Hiraki, K. (2011).
Journal of Instruction-Level Parallelism, 13, 1-24.
Change-Id: I0d4b7f7afc2ab4938bdd8755bfed26e26a28530c
Reviewed-on: https://gem5-review.googlesource.com/c/15096
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Prefetchers can be configured to operate with virtual or physical addreses.
The option can be configured through the "use_virtual_addresses" parameter
of the Prefetcher object.
Change-Id: I4f8c3687988afecc8a91c3c5b2d44cc0580f72aa
Reviewed-on: https://gem5-review.googlesource.com/c/14416
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Add a getter and a setter function to access CacheBlk::whenReady
to encapsulate the variable and allow error checking. This error
checking consists on verifying that writes to a block after it
has been inserted follow a chronological order.
As a side effect, tickInserted retain its value until updated,
that is, it is not reset in invalidate().
Change-Id: Idc3c5a99c3f002ee9acc2424f00e554877fd3a69
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14715
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Derived classes with virtual functions need to define a virtual
destructor or a protected destructor otherwise calling the base class
destructor has undefined behavior. This change adds a virtual
distructor in the base class.
Change-Id: I1c855aa56dff6585ff99b9147bdb4eb9729a0a53
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/14815
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Previously a loop was being done to check whether the
block was valid/secure or not. Variables have been
added to skip this loop and save and update sector
block state when sub-blocks are validated, invalidated
and secured.
Change-Id: Ie1734f7dfda9698c7bf22a1fcbfc47ffb9239cea
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14363
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Neither assert(0) nor assert(false) give any hint as to why control
getting to them is bad, and their more descriptive versions,
assert(0 && "description") and assert(false && "description"), jury
rig assert to add an error message when the utility function panic()
already does that directly with better formatting options.
This change replaces that flavor of call to assert with panic, except
in the actual code which processes the formatting that panic uses (to
avoid infinitely recurring error handling), and in some *.sm files
since I don't know what rules those have to follow and don't want to
accidentaly break them.
Change-Id: I8addfbfaf77eaed94ec8191f2ae4efb477cefdd0
Reviewed-on: https://gem5-review.googlesource.com/c/14636
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
In order to allow polymorphism of the block these two
functions have been added, and all direct status
assignments to these bits have been substituted.
We also assert that the block has been invalidated
before insertion. Then the block is validated in
the insertion.
Change-Id: Ie7be42408721ad4c2c9dc880f82a62cb594f8668
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14362
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Move the unordered_map outside of the PCTable, as it
belongs to the StridePrefetcher. By doing so we are
moving towards a table that ressembles the ones of
the Tags classes.
Some functions have been moved from the prefetcher to
the PCTable, as they didn't belong there. As such, they
have been renamed to remove the unnecessary prefix.
Change-Id: I3e54bc7dee65e1f78d96b0d548ac8345b7bd4364
Signed-off-by: Daniel <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14358
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Return a pointer to the entry instead of returning a
boolean and passing a pointer reference. As a side
effect, change the name of the function to be more
descriptive of the functionality.
Change-Id: Iad44979e98031754c1d0857b1790c0eaf77e9765
Signed-off-by: Daniel <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14356
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Access latency was not being calculated properly, as it was
always assuming that for hits reads take as long as writes,
and that parallel accesses would produce the same latency
for read and write misses.
By moving the calculation to the Cache we can use the write/
read information, reduce latency variables duplication and
remove Cache dependency from Tags.
The tag lookup latency is still calculated by the Tags.
Change-Id: I71bc68fb5c3515b372c3bf002d61b6f048a45540
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13697
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Requests, for which a cache has already committed to respond do not
perform any lookups. Previously in atomic mode the packet would pay
the lookup latency while in timing it wouldn't. This patch aligns
recvAtomic with recvTimingReq and removes the lookup latency from the
the handling of such requests.
Change-Id: I50a0631f8058e5086d94d55af0e1788a60e2883f
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/14175
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Since the tag classes are subclasses of SimObject, they inherit an
init function which does generic initialization at simulation startup
and which doesn't take any parameters. A new function was added which
does take a parameter, and which is just for doing tag specific
initialization as triggered by the base cache. These two names clashed,
and clang complained that the tag local name was hiding the SimObject
name (which it was).
Change-Id: I399775aceaf8f1a8e2646d434facef22e6d3e7d0
Reviewed-on: https://gem5-review.googlesource.com/c/13875
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Classes were using memcpy instead of the Packet functions
created for writing to/from the packet. This allows these
writes to be better checked and tracked.
This also fixes a bug in MemCheckerMonitor, which was using
the incorrect type for the packet pointer.
Change-Id: I5bbc8a24e59464e8219bb6d54af8209e6d4ee1af
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13695
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Block was being invalidated twice when not a tempBlock.
Make explicit that the else case is only to be applied
when handling the tempBlock, as otherwise the Tags
should be taking care of the invalidation.
Change-Id: Ie7603fdbe156c54e94bbdc83541b55e66f8d250f
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13895
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
To avoid deadlocks ruby objects typically prioritize the handling of
responses to all other events. The order in which in_port statements
are written determine the order in which they are handled. This patch
fixes the order of in_order statements for the L2 cache in the
MOESI_CMP_directory.
Change-Id: I62248b0480a88ac2cd945425155f0961a1cf6cb1
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13595
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Enable the cache to detect contiguous writes and hold on to the MSHR
long enough to allow the entire line to be written. If the whole line
is written, the MSHR will be sent out as an invalidation requests, as
it is part of a whole-line write, i.e. no-fetch-on-write.
The cache is also able to switch to a write-no-allocate policy on the
actual completion of the writes, and instead use the tempBlock and
turn the write operation into a writeback.
These policies are all well-known, and described in works such as
Jouppi, Cache Write Policies and Performance, vol 21, no 2, ACM, 1993.
Change-Id: I19792f2970b3c6798c9b2b493acdd156897284ae
Reviewed-on: https://gem5-review.googlesource.com/c/12907
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
An MSHR is allocated and the computed latency determines when the MSHR
will be ready and can be serviced by the cache. This patch adds a
function that allows changing the time that an MSHR is ready and
adjusts the queue such that other MSHRs can be serviced first if they
are ready.
Change-Id: Ie908191fcb3c2d84d4c6f855c8b1e41ca5881bff
Reviewed-on: https://gem5-review.googlesource.com/c/12906
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
This patch changes how we deal with whole-line writes their
responses. With these changes, we use the MSHR tracking to determine
if a whole-line is written, and on a fill we simply handle the
invalidation response, with the actual writes taking place as part of
satisfying the CPU-side hit.
Change-Id: I9a18e41a95db3c20b97f8bca7d95ff33d35a578b
Reviewed-on: https://gem5-review.googlesource.com/c/12905
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
This patch adds support for determining whether the targets in an MSHR
are 1) only writes and 2) whether these writes are effectively a
whole-line write. This patch adds the necessary functions in the MSHR
to allow for write coalescing in the cache.
Change-Id: I2c9a9a83d2d9b506a491ba5b0b9ac1054bdb31b4
Reviewed-on: https://gem5-review.googlesource.com/c/12904
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
The NULL ISA doesn't really have an endianness. Now that the packet
accessors which consumed that endianness are gone, we can get rid of
that setting as well.
Change-Id: I8dd4c7b8236b07df4458fea377865f30141121d4
Reviewed-on: https://gem5-review.googlesource.com/c/13466
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
The accessors are used for debugging output. If we're using an ISA
where there's an endianness, we use that explicitly, falling back to a
binary dump if the size isn't supported. If not, then we just dump the
data without interpretation regardless of size.
Change-Id: Ib050c4c876ee41f17cfd14ad657150bf6ab1de39
Reviewed-on: https://gem5-review.googlesource.com/c/13464
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
This avoids a place where data has its endianness switched so that when
the endianness based accessors switch it back it returns to normal. It
also makes it easier to show intent when accessing single bytes where
endianness doesn't matter, and there's no contextual endianness.
Change-Id: I1b97396c1b9bb39727d35112d90e3969e5fe0aab
Reviewed-on: https://gem5-review.googlesource.com/c/13455
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
ReplaceableEntry is referenced by many classes that do
not necessarily need access to the replacement policies.
Therefore, in order to allow better compilation units,
we factor it out to a new file.
Change-Id: I0823567bf1ca336ffcdf783682ef473e8878d7fd
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13418
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
