From 4c125f3b7591758ebd96c3ac3ff469480b7aaea2 Mon Sep 17 00:00:00 2001 From: Mahmoud Mandour Date: Fri, 9 Jul 2021 15:30:04 +0100 Subject: [PATCH] docs/devel: Added cache plugin to the plugins docs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mahmoud Mandour Signed-off-by: Alex Bennée Message-Id: <20210628053808.17422-1-ma.mandourr@gmail.com> Message-Id: <20210709143005.1554-40-alex.bennee@linaro.org> --- docs/devel/tcg-plugins.rst | 59 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst index 179867e9c1..7e54f12837 100644 --- a/docs/devel/tcg-plugins.rst +++ b/docs/devel/tcg-plugins.rst @@ -344,3 +344,62 @@ which will output an execution trace following this structure:: 0, 0xd32, 0xf9893014, "adds r0, #0x14" 0, 0xd34, 0xf9c8f000, "bl #0x10c8" 0, 0x10c8, 0xfff96c43, "ldr r3, [r0, #0x44]", load, 0x200000e4, RAM + +- contrib/plugins/cache + +Cache modelling plugin that measures the performance of a given cache +configuration when a given working set is run:: + + qemu-x86_64 -plugin ./contrib/plugins/libcache.so \ + -d plugin -D cache.log ./tests/tcg/x86_64-linux-user/float_convs + +will report the following:: + + Data accesses: 996479, Misses: 507 + Miss rate: 0.050879% + + Instruction accesses: 2641737, Misses: 18617 + Miss rate: 0.704726% + + address, data misses, instruction + 0x424f1e (_int_malloc), 109, movq %rax, 8(%rcx) + 0x41f395 (_IO_default_xsputn), 49, movb %dl, (%rdi, %rax) + 0x42584d (ptmalloc_init.part.0), 33, movaps %xmm0, (%rax) + 0x454d48 (__tunables_init), 20, cmpb $0, (%r8) + ... + + address, fetch misses, instruction + 0x4160a0 (__vfprintf_internal), 744, movl $1, %ebx + 0x41f0a0 (_IO_setb), 744, endbr64 + 0x415882 (__vfprintf_internal), 744, movq %r12, %rdi + 0x4268a0 (__malloc), 696, andq $0xfffffffffffffff0, %rax + ... + +The plugin has a number of arguments, all of them are optional: + + * arg="limit=N" + + Print top N icache and dcache thrashing instructions along with their + address, number of misses, and its disassembly. (default: 32) + + * arg="icachesize=N" + * arg="iblksize=B" + * arg="iassoc=A" + + Instruction cache configuration arguments. They specify the cache size, block + size, and associativity of the instruction cache, respectively. + (default: N = 16384, B = 64, A = 8) + + * arg="dcachesize=N" + * arg="dblksize=B" + * arg="dassoc=A" + + Data cache configuration arguments. They specify the cache size, block size, + and associativity of the data cache, respectively. + (default: N = 16384, B = 64, A = 8) + + * arg="evict=POLICY" + + Sets the eviction policy to POLICY. Available policies are: :code:`lru`, + :code:`fifo`, and :code:`rand`. The plugin will use the specified policy for + both instruction and data caches. (default: POLICY = :code:`lru`)