Re: [RFC PATCH v3 0/4] Cache TCG plugin & symbol-resolution API

[Alex Bennée]

Mahmoud Mandour <ma.mandourr@gmail.com> writes:

> This RFC series introduces a new cache TCG plugin that models separate
> L1 data cache and L1 instruction cache and uses one shared cache for
> all the cores.
>
> It also includes a commit by Alex that adds an API call that resolves
> the symbol of an insn.
>
> The original RFC patch posted by Alex Bennée included incorporating
> symbol resolution into the cache plugin that caused conflicts, so I
> dropped the plugin additions from that and introduced them afterwards.

Queued patches 1-2 to plugins/next, will queue the rest from next
revision. Could you please also add a section to
docs/devel/tcg-plugins.rst to detail the argument options.

>
> v2 -> v3:
>     Precomputed the value of block size shift once and stored in the
>     cache.
>
>     Removed tag shifting since it's okay to leave the tag in the
>     high-order bits and mask out set index and block offset.
>
>     Used one hashtable to store InsnData structs and made the structs
>     have separate counters for data misses and instruction misses.
>
>     Used a boolean to indicate whether an access resulted in a hit or a
>     miss.
>
>     Inserted an InsnData struct into the hashtable on translation-time
>     and made sure we do so once so that we don't rewrite the struct if
>     an instruction is translated multiple times.
>
>     Made the output format for most-missing instructions more
>     machine-readable.
>
>     Removed trace-generation.
>
>     Freed tokenized strings after argument parsing.
>
>     Returned null from cache_init() if argument cache config is bad.
>
>     Used one enum to indicate the chosen eviction policy.
>
>     Added function pointers for cache update and metadata initialization
>     and destroying. Those pointers are assigned to policy-specific
>     functions.
>
>     Remade LRU. Assigned a generation number that is incremented on each
>     set access to the currently-accessed block's priority. On miss, 
>     evicted the block with the least generation number.
>
>     Allowed to give multiple "evict" arguments and sticked to the last
>     one.
>
> Alex Bennée (1):
>   plugins/api: expose symbol lookup to plugins
>
> Mahmoud Mandour (3):
>   plugins: Added a new cache modelling plugin.
>   plugins/cache: Enabled cache parameterization
>   plugins/cache: Added FIFO and LRU eviction policies.
>
>  contrib/plugins/Makefile   |   1 +
>  contrib/plugins/cache.c    | 642 +++++++++++++++++++++++++++++++++++++
>  include/qemu/qemu-plugin.h |   9 +
>  plugins/api.c              |   6 +
>  4 files changed, 658 insertions(+)
>  create mode 100644 contrib/plugins/cache.c


-- 
Alex Bennée