Re: [PATCH v4 4/5] docs/devel: Added cache plugin to the plugins docs

[Mahmoud Mandour <ma.mandourr@gmail.com>]

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On Wed, Jun 23, 2021 at 2:55 PM Mahmoud Mandour <ma.mandourr@gmail.com>
wrote:

> Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
> ---
>  docs/devel/tcg-plugins.rst | 60 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
>
> diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst
> index 18c6581d85..9d90110cbf 100644
> --- a/docs/devel/tcg-plugins.rst
> +++ b/docs/devel/tcg-plugins.rst
> @@ -319,3 +319,63 @@ the user to see what hardware is accessed how often.
> It has a number of options:
>        off:0000001c, 1, 2
>        off:00000020, 1, 2
>        ...
> +
> +- 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 ./libcache.so -d plugin -D cache.log \
> +    ./build/tests/tcg/x86_64-linux-user/float_convs
> +
>

Oops that's a wrong command... Should've been

./x86_64-linux-user/qemu-x86_64 -plugin ./contrib/plugins/libcache.so -d
plugin -D cache.log \
./tests/tcg/x86_64-linux-user/float_convs

If you find the patch suitable and can edit the command before queueing it,
otherwise tell me
if you want me to resend :)


> +
> +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`)
> --
> 2.25.1
>
>

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