Commit graph

118 commits

Author SHA1 Message Date
Stephan Diestelhorst
19c2a606fa mem: Add "const" attribute to Packet getters
Add a "const" keywords to the getters in the Packet class so these can be
invoked on const Packet objects.
2013-10-31 13:41:13 -05:00
Uri Wiener
a8fbfefb5e mem: Adding verbose debug output in the memory system
This patch provides useful printouts throughut the memory system. This
includes pretty-printed cache tags and function call messages
(call-stack like).
2013-04-22 13:20:33 -04:00
Andreas Hansson
b3fc8839c4 mem: Make packet bus-related time accounting relative
This patch changes the bus-related time accounting done in the packet
to be relative. Besides making it easier to align the cache timing to
cache clock cycles, it also makes it possible to create a Last-Level
Cache (LLC) directly to a memory controller without a bus inbetween.

The bus is unique in that it does not ever make the packets wait to
reflect the time spent forwarding them. Instead, the cache is
currently responsible for making the packets wait. Thus, the bus
annotates the packets with the time needed for the first word to
appear, and also the last word. The cache then delays the packets in
its queues before passing them on. It is worth noting that every
object attached to a bus (devices, memories, bridges, etc) should be
doing this if we opt for keeping this way of accounting for the bus
timing.
2013-02-19 05:56:06 -05:00
Andreas Hansson
362160c8ae mem: Add deferred packet class to prefetcher
This patch removes the time field from the packet as it was only used
by the preftecher. Similar to the packet queue, the prefetcher now
wraps the packet in a deferred packet, which also has a tick
representing the absolute time when the packet should be sent.
2013-02-19 05:56:06 -05:00
Sascha Bischoff
86a4d09269 mem: Fix SenderState related cache deadlock
This patch fixes a potential deadlock in the caches. This deadlock
could occur when more than one cache is used in a system, and
pkt->senderState is modified in between the two caches. This happened
as the caches relied on the senderState remaining unchanged, and used
it for instantaneous upstream communication with other caches.

This issue has been addressed by iterating over the linked list of
senderStates until we are either able to cast to a MSHR* or
senderState is NULL. If the cast is successful, we know that the
packet has previously passed through another cache, and therefore
update the downstreamPending flag accordingly. Otherwise, we do
nothing.
2013-02-19 05:56:06 -05:00
Andreas Hansson
0622f30961 mem: Add predecessor to SenderState base class
This patch adds a predecessor field to the SenderState base class to
make the process of linking them up more uniform, and enable a
traversal of the stack without knowing the specific type of the
subclasses.

There are a number of simplifications done as part of changing the
SenderState, particularly in the RubyTest.
2013-02-19 05:56:05 -05:00
Ali Saidi
396600de10 mem: Add a gasket that allows memory ranges to be re-mapped.
For example if DRAM is at two locations and mirrored this patch allows the
mirroring to occur.
2012-09-25 11:49:40 -05:00
Andreas Hansson
c60db56741 Packet: Remove NACKs from packet and its use in endpoints
This patch removes the NACK frrom the packet as there is no longer any
module in the system that issues them (the bridge was the only one and
the previous patch removes that).

The handling of NACKs was mostly avoided throughout the code base, by
using e.g. panic or assert false, but in a few locations the NACKs
were actually dealt with (although NACKs never occured in any of the
regressions). Most notably, the DMA port will now never receive a NACK
and the backoff time is thus never changed. As a consequence, the
entire backoff mechanism (similar to a PCI bus) is now removed and the
DMA port entirely relies on the bus performing the arbitration and
issuing a retry when appropriate. This is more in line with e.g. PCIe.

Surprisingly, this patch has no impact on any of the regressions. As
mentioned in the patch that removes the NACK from the bridge, a
follow-up patch should change the request and response buffer size for
at least one regression to also verify that the system behaves as
expected when the bridge fills up.
2012-08-22 11:39:59 -04:00
Ali Saidi
1b370431d0 sim: Remove FastAlloc
While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe.
After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc
when running twolf for ARM.
2012-06-05 01:23:08 -04:00
Andreas Hansson
cad802761a Packet: Unify the use of PortID in packet and port
This patch removes the Packet::NodeID typedef and unifies it with the
Port::PortId. The src and dest fields in the packet are used to hold a
port id (e.g. in the bus), and thus the two should actually be the
same.

The typedef PortID is now global (in base/types.hh) and aligned with
the ThreadID in terms of capitalisation and naming of the
InvalidPortID constant.

Before this patch, two flags were used for valid destination and
source, rather than relying on a named value (InvalidPortID), and
this is now redundant, as the src and dest field themselves are
sufficient to tell whether the current value is a valid port
identifier or not. Consequently, the VALID_SRC and VALID_DST are
removed.

As part of the cleaning up, a number of int parameters and local
variables are updated to use PortID.

Note that Ruby still has its own NodeID typedef. Furthermore, the
MemObject getMaster/SlavePort still has an int idx parameter with a
default value of -1 which should eventually change to PortID idx =
InvalidPortID.
2012-05-30 05:29:42 -04:00
Andreas Hansson
6a54f7fc5f Packet: Updated comments for src and dest fields
This patch updates the comments for the src and dest fields to reflect
their actual use. Due to a number of patches (e.g. removing the
Broadcast flag), the old comments are no longer indicative of the
current usage.
2012-05-30 05:29:07 -04:00
Andreas Hansson
3e0ed08706 Packet: Cleaning up packet command and attribute
This patch removes unused commands and attributes from the packet to
avoid any confusion. It is part of an effort to clear up how and where
different commands and attributes are used.
2012-05-23 09:18:04 -04:00
Andreas Hansson
750f33a901 MEM: Remove the Broadcast destination from the packet
This patch simplifies the packet by removing the broadcast flag and
instead more firmly relying on (and enforcing) the semantics of
transactions in the classic memory system, i.e. request packets are
routed from a master to a slave based on the address, and when they
are created they have neither a valid source, nor destination. On
their way to the slave, the request packet is updated with a source
field for all modules that multiplex packets from multiple master
(e.g. a bus). When a request packet is turned into a response packet
(at the final slave), it moves the potentially populated source field
to the destination field, and the response packet is routed through
any multiplexing components back to the master based on the
destination field.

Modules that connect multiplexing components, such as caches and
bridges store any existing source and destination field in the sender
state as a stack (just as before).

The packet constructor is simplified in that there is no longer a need
to pass the Packet::Broadcast as the destination (this was always the
case for the classic memory system). In the case of Ruby, rather than
using the parameter to the constructor we now rely on setDest, as
there is already another three-argument constructor in the packet
class.

In many places where the packet information was printed as part of
DPRINTFs, request packets would be printed with a numeric "dest" that
would always be -1 (Broadcast) and that field is now removed from the
printing.
2012-04-14 05:45:55 -04:00
Koan-Sin Tan
7d4f187700 clang: Enable compiling gem5 using clang 2.9 and 3.0
This patch adds the necessary flags to the SConstruct and SConscript
files for compiling using clang 2.9 and later (on Ubuntu et al and OSX
XCode 4.2), and also cleans up a bunch of compiler warnings found by
clang. Most of the warnings are related to hidden virtual functions,
comparisons with unsigneds >= 0, and if-statements with empty
bodies. A number of mismatches between struct and class are also
fixed. clang 2.8 is not working as it has problems with class names
that occur in multiple namespaces (e.g. Statistics in
kernel_stats.hh).

clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which
causes confusion between the container std::set and the function
Packet::set, and this is currently addressed by not including the
entire namespace std, but rather selecting e.g. "using std::vector" in
the appropriate places.
2012-01-31 12:05:52 -05:00
Nilay Vaish
9481d05b8a MemCmd: Add a command for invalidation requests to LSQ
This command will be sent from the memory system (Ruby) to the LSQ of
an O3 CPU so that the LSQ, if it needs to, invalidates the address in
the request packet.
2012-01-23 11:07:11 -06:00
Geoffrey Blake
e826d23a2e Packet: Add derived class FunctionalPacket to enable partial functional reads
This adds the derived class FunctionalPacket to fix a long standing
deficiency in the Packet class where it was unable to handle finding data to
partially satisfy a functional access.  Made this a derived class as
functional accesses are used only in certain contexts and to not add any
additional overhead to the existing Packet class.
2012-01-09 18:10:05 -06:00
Brad Beckmann ext:(%2C%20Nilay%20Vaish%20%3Cnilay%40cs.wisc.edu%3E)
c86f849d5a Ruby: Add support for functional accesses
This patch rpovides functional access support in Ruby. Currently only
the M5Port of RubyPort supports functional accesses. The support for
functional through the PioPort will be added as a separate patch.
2011-06-30 19:49:26 -05:00
Nathan Binkert
39a055645f includes: sort all includes 2011-04-15 10:44:06 -07:00
Somayeh Sardashti
c8bbfed937 This patch supports cache flushing in MOESI_hammer 2011-03-28 10:49:45 -05:00
Brad Beckmann
273e3d4924 mem: Added support for Null data packet
The packet now identifies whether static or dynamic data has been allocated and
is used by Ruby to determine whehter to copy the data pointer into the ruby
request.  Subsequently, Ruby can be told not to update phys memory when
receiving packets.
2011-02-06 22:14:19 -08:00
Steve Reinhardt
6f1187943c Replace curTick global variable with accessor functions.
This step makes it easy to replace the accessor functions
(which still access a global variable) with ones that access
per-thread curTick values.
2011-01-07 21:50:29 -08:00
Ali Saidi
aef4a9904e CPU/Cache: Fix some errors exposed by valgrind 2010-09-30 09:35:19 -05:00
Steve Reinhardt
e918536380 cache: improve coherence handling of writebacks
If we write back an exclusive copy, we now mark it
as such, so the cache receiving the writeback can
mark its copy as exclusive.  This avoids some
unnecessary upgrade requests when a cache later
tries to re-acquire exclusive access to the block.
2010-09-21 23:07:34 -07:00
Steve Reinhardt
1249728494 cache: fail SC when invalidated while waiting for bus
Corrects an oversight in cset f97b62be544f.  The fix there only
failed queued SCUpgradeReq packets that encountered an
invalidation, which meant that the upgrade had to reach the L2
cache.  To handle pending requests in the L1 we must similarly
fail StoreCondReq packets too.
2010-09-09 14:40:19 -04:00
Steve Reinhardt
62c06c1403 mem: fix dumb typo in copyrights 2010-08-25 14:08:27 -07:00
Brad Beckmann
8e5c441a54 ruby: fix ruby llsc support to sync sc outcomes
Added support so that ruby can determine the outcome of store conditional
operations and reflect that outcome to M5 physical memory and cpus.
2010-08-20 11:46:12 -07:00
Steve Reinhardt
f24ae2ec2a cache: fail store conditionals when upgrade loses race
Requires new "SCUpgradeReq" message that marks upgrades
for store conditionals, so downstream caches can fail
these when they run into invalidations.
See http://www.m5sim.org/flyspray/task/197
2010-06-16 15:25:57 -07:00
Steve Reinhardt
57f2b7db11 cache: fix dirty bit setting
Only set the dirty bit when we actually write to a block
(not if we thought we might but didn't, as in a failed
SC or CAS).  This requires makeing sure the dirty bit
stays set when we get an exclusive (writable) copy
in a cache-to-cache transfer from another owner, which
n turn requires copying the mem-inhibit flag from
timing-mode requests to their associated responses.
2010-06-16 15:25:57 -07:00
Nathan Binkert
c8f296bca0 packet: add a method to set the size 2010-03-12 17:31:08 -08:00
Brad Beckmann
6e1dc2546c m5: Added isValidSrc and isValidDest calls to packet.hh 2009-11-18 13:55:58 -08:00
Nathan Binkert
6faf377b53 types: clean up types, especially signed vs unsigned 2009-06-04 23:21:12 -07:00
Nathan Binkert
a0104b6ff6 request: add accessor and constructor for setting time other than curTick 2009-05-29 15:30:16 -07:00
Nathan Binkert
8d2e51c7f5 includes: sort includes again 2009-05-17 14:34:52 -07:00
Nathan Binkert
eef3a2e142 types: Move stuff for global types into src/base/types.hh
--HG--
rename : src/sim/host.hh => src/base/types.hh
2009-05-17 14:34:50 -07:00
Steve Reinhardt
7f8ea68a30 request: split public and private flags into separate fields.
This frees up needed space for more public flags.  Also:
- remove unused Request accessor methods
- make Packet use public Request accessors, so it need not be a friend
2009-04-20 18:40:00 -07:00
Gabe Black
bd6f2bb538 Mem: Change isLlsc to isLLSC. 2009-04-19 21:44:15 -07:00
Gabe Black
3e5f487663 Memory: Rename LOCKED for load locked store conditional to LLSC. 2009-04-19 04:25:01 -07:00
Nathan Binkert
e141cb7441 flags: Change naming of functions to be clearer 2008-12-06 14:18:18 -08:00
Nathan Binkert
5711282f87 Fix a bunch of bugs I introduced when I changed the flags stuff for packets.
I did some of the flags and assertions wrong. Thanks to Brad Beckmann
for pointing this out.  I should have run the opt regressions instead
of the fast. I also screwed up some of the logical functions in the Flags
class.
2008-11-14 04:55:30 -08:00
Nathan Binkert
3535d746ab style: clean up the Packet stuff 2008-11-10 11:51:17 -08:00
Gabe Black
e459013182 Create a message port for sending messages as apposed to reading/writing a memory range. 2008-10-12 12:08:51 -07:00
Steve Reinhardt
8e7ddce284 Use ReadResp instead of LoadLockedResp for LoadLockedReq responses. 2008-07-15 14:38:51 -04:00
Steve Reinhardt
623dd7ed3a Delete the Request for a no-response Packet
when the Packet is deleted, since the requester
can't possibly do it.

--HG--
extra : convert_revision : 8571b144ecb3c70efc06d09faa8b3161fb58352d
2008-03-24 01:08:02 -04:00
Steve Reinhardt
93ab43288a Don't FastAlloc MSHRs since we don't allocate them on the fly.
--HG--
extra : convert_revision : 02775cfb460afe6df0df0938c62cccd93a71e775
2008-03-24 01:08:02 -04:00
Steve Reinhardt
6c5a3ab8b2 Add ReadRespWithInvalidate to handle multi-level coherence situation
where we defer a response to a read from a far-away cache A, then later
defer a ReadExcl from a cache B on the same bus as us.  We'll assert
MemInhibit in both cases, but in the latter case MemInhibit will keep
the invalidation from reaching cache A.  This special response tells
cache A that it gets the block to satisfy its read, but must immediately
invalidate it.

--HG--
extra : convert_revision : f85c8b47bb30232da37ac861b50a6539dc81161b
2008-01-02 15:22:38 -08:00
Steve Reinhardt
cde5a79eab Additional comments and helper functions for PrintReq.
--HG--
extra : convert_revision : 7eadf9b7db8c0289480f771271b6efe2400006d4
2008-01-02 13:46:22 -08:00
Steve Reinhardt
3952e41ab1 Add functional PrintReq command for memory-system debugging.
--HG--
extra : convert_revision : 73b753e57c355b7e6873f047ddc8cb371c3136b7
2008-01-02 12:20:15 -08:00
Gabe Black
7227ab5f22 Merge with head
--HG--
extra : convert_revision : cc73b9aaf73e9dacf52f3350fa591e67ca4ccee6
2007-08-26 21:45:40 -07:00
Steve Reinhardt
8705b0799b packet: get rid of unused intersect() function.
--HG--
extra : convert_revision : f0a2947ccc49e0d18bc17a59371fa396d9ebd6c0
2007-07-27 12:46:55 -07:00
Steve Reinhardt
c3bf59dcb9 Add downward express snoops for invalidations.
--HG--
extra : convert_revision : 4916fa9721d727d8416ad8c07df3a8171d02b2b4
2007-07-26 17:04:17 -07:00