[Tarantool-patches] [PATCH luajit v2] memprof: enrich symtab when new trace is allocated

[Igor Munkin]

Misha,

Thanks for the patch!

I've fixed few issues I've found by myself, LGTM otherwise. CI is
green[1], so I've I've checked the patch into tarantool branch in
tarantool/luajit and bumped a new version in master.

On 08.12.21, Mikhail Shishatskiy wrote:
> Since symtab can be enriched with new prototypes, it
> can be enriched with new traces as well. This feature
> can help to investigate trace-generation-heavy apps
> with memprof.
> 
> This patch introduces the functionality described above by
> adding a `prof_epoch` counter to the `GCtrace` structure.
> If the profiler meets allocation from a trace, it checks if
> the trace was already streamed to the symtab. If not,
> a symtab entry is dumped inside an <event-symtab>:
> 
> | event-symtab := event-header sym?
> | sym := sym-lua | sym-trace
> | sym-trace := trace-no sym-addr line-no
> 
> Since this patch, traces are no longer identified by address,
> as all the name collisions are resolved with symbols epochs.
> 
> Also, the API of <utils/symtab.lua> changed: function `parse_sym_trace`
> is now public in order to use it from the <memrprof/parser.lua> module.
> 
> Follows up tarantool/tarantool#5815
> ---
> 
> CI: https://github.com/tarantool/tarantool/tree/shishqa/enrich-symtab-when-trace-is-allocated-v2
> branch: https://github.com/tarantool/luajit/tree/shishqa/enrich-symtab-when-trace-is-allocated-v2
> 
>  src/lj_jit.h                                  |  8 +++++++
>  src/lj_memprof.c                              | 22 +++++++++++++------
>  src/lj_memprof.h                              |  5 +++--
>  src/lj_trace.c                                |  3 +++
>  .../misclib-memprof-lapi.test.lua             | 13 +++++------
>  tools/memprof/parse.lua                       |  3 ++-
>  tools/utils/symtab.lua                        | 14 ++++--------
>  7 files changed, 41 insertions(+), 27 deletions(-)
> 

> -- 
> 2.33.1
> 

[1]: https://github.com/tarantool/luajit/commit/11ab4c4

-- 
Best regards,
IM