[Tarantool-patches] [RFC v4] rfc: luajit metrics

[Igor Munkin]

Sergey,

Thanks, the RFC LGTM in general now, but please consider the last minor
comments below.

On 08.10.20, Sergey Kaplun wrote:
> Hi, Igor! Thanks for the review!
> 
> On 08.10.20, Igor Munkin wrote:
> > Sergey,
> > 

<snipped>

> > 
> > Minor: ChangeLog is misordered (the latest changes are the first entry).
> 
> Thanks!
> 
> Forgot to add ChangeLog to patch:
> @ChangeLog:
>  * Add Lua and C API for LuaJIT platform metrics about:
>    - overall amount of allocated tables, cdata and udata objects
>    - number of incremental GC steps grouped by GC state
>    - number of string hashes hits and misses
>    - amount of allocated and freed memory
>    - number of trace aborts, number of traces and restored snapshots

The related issue should be also mentioned here.

> 
> > 
> > > 
> > >  doc/rfc/5187-luajit-metrics.md | 299 +++++++++++++++++++++++++++++++++
> > >  1 file changed, 299 insertions(+)
> > >  create mode 100644 doc/rfc/5187-luajit-metrics.md
> > > 
> > > diff --git a/doc/rfc/5187-luajit-metrics.md b/doc/rfc/5187-luajit-metrics.md
> > > new file mode 100644
> > > index 000000000..02f5b559f
> > > --- /dev/null
> > > +++ b/doc/rfc/5187-luajit-metrics.md
> > > @@ -0,0 +1,299 @@
> > 

<snipped>

> 
> > 
> > > +- `jit_mcode_size` -- whenever new MCode area is allocated `jit_mcode_size` is
> > > +  increased at corresponding size in bytes. Sets to 0 when all mcode area is
> > > +  freed.
> > 
> > How does it change, when a trace is collected as a result of its flush?
> 
> It doesn't. IINM, this area will be reused later for other traces.
> MCode area is linked with jit_State not with trace by itself. Trace just
> reserve MCode area that needed.

I guess this should be explicitly mentioned here then.

> 

<snipped>

> 
> -- 
> Best regards,
> Sergey Kaplun

-- 
Best regards,
IM