By default L2 is not enabled and is enabled by either using the
newly-introduced "l2" boolean argument, or by setting any of the L2
cache parameters using args. On specifying "l2=on", the default cache
configuration is used.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210810134844.166490-5-ma.mandourr@gmail.com>
Message-Id: <20211026102234.3961636-17-alex.bennee@linaro.org>
This way of handling args is more lenient and sets a better framework to
parse boolean command line arguments.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210810134844.166490-4-ma.mandourr@gmail.com>
Message-Id: <20211026102234.3961636-16-alex.bennee@linaro.org>
This adds an implementation of a simple L2 configuration, in which a
unified L2 cache (stores both blocks of instructions and data) is
maintained for each core separately, with no inter-core interaction
taken in account. The L2 cache is used as a backup for L1 and is only
accessed if the wanted block does not exist in L1.
In terms of multi-threaded user-space emulation, the same approximation
of L1 is done, a static number of caches is maintained, and each and
every memory access initiated by a thread will have to go through one of
the available caches.
An atomic increment is used to maintain the number of L2 misses per
instruction.
The default cache parameters of L2 caches is:
2MB cache size
16-way associativity
64-byte blocks
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210810134844.166490-3-ma.mandourr@gmail.com>
Message-Id: <20211026102234.3961636-15-alex.bennee@linaro.org>
Multicore L1 cache modelling is introduced and is supported for both
full system emulation and linux-user.
For full-system emulation, L1 icache and dcache are maintained for each
available core, since this information is exposed to the plugin through
`qemu_plugin_n_vcpus()`.
For linux-user, a static number of cores is assumed (default 1 core, and
can be provided as a plugin argument `cores=N`). Every memory access
goes through one of these caches, this approach is taken as it's
somewhat akin to what happens on real setup, where a program that
dispatches more threads than the available cores, they'll thrash
each other
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Message-Id: <20210803151301.123581-2-ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
It's not necessary to lock the address translation portion of the
vcpu_mem_access callback.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210714172151.8494-3-ma.mandourr@gmail.com>
Message-Id: <20210720232703.10650-23-alex.bennee@linaro.org>
This manifests itself when associativity degree is greater than the
number of sets and FIFO is used, otherwise it's also a memory leak
whenever FIFO was used.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210714172151.8494-2-ma.mandourr@gmail.com>
Message-Id: <20210720232703.10650-22-alex.bennee@linaro.org>
Implemented FIFO and LRU eviction policies. Now one of the three
eviction policies can be chosen as an argument. On not specifying an
argument, LRU is used by default.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210623125458.450462-4-ma.mandourr@gmail.com>
Message-Id: <20210709143005.1554-39-alex.bennee@linaro.org>
Added a cache modelling plugin that uses a static configuration used in
many of the commercial microprocessors and uses random eviction policy.
The purpose of the plugin is to identify the most cache-thrashing
instructions for both instruction cache and data cache.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210623125458.450462-2-ma.mandourr@gmail.com>
Message-Id: <20210709143005.1554-37-alex.bennee@linaro.org>
Mahmoud Mandour