[Tarantool-patches] [PATCH luajit v2] memprof: report JIT-side allocations as internal

[Sergey Kaplun]

Hi, thanks for the fixes!

Please, move test adjustment mentioned below to the patch for the symtab
with group allocations by trace's number.
Otherwise, LGTM.

On 29.07.21, Mikhail Shishatskiy wrote:
> There are cases when the memory profiler attempts to attribute
> allocations triggered by the JIT engine recording phase
> with a Lua function to be recorded. In this case,
> lj_debug_frameline() may return BC_NOPOS (i.e. a negative value).
> 
> Previously, these situations were ignored and the profiler
> reported, that the source line was equal to zero.
> 
> This patch adjusts profiler behavior to treat allocations
> described above as internal by dumping ASOURCE_INT if
> lj_debug_frameline() returns a negative value.
> 
> Resolves tarantool/tarantool#5679
> ---
> 
> Issue: https://github.com/tarantool/tarantool/issues/5679
> Branch: https://github.com/tarantool/luajit/tree/shishqa/gh-5679-report-jit-allocations-as-internal
> CI: https://github.com/tarantool/tarantool/tree/shishqa/gh-5679-report-jit-allocations-as-internal
> 
> Changes in v2:
>   - Fixed commit title to fit in width of 50 symbols;
>   - Rebased to the branch [1];
>   - Reused default_payload() as a payload to test patch behavior.
> 
> [1]: https://github.com/tarantool/luajit/tree/shishqa/gh-5814-group-allocations-on-trace-by-trace-number
> 
>  src/lj_memprof.c                              | 28 ++++++++++++-------
>  .../misclib-memprof-lapi.test.lua             | 16 ++++++++---
>  2 files changed, 30 insertions(+), 14 deletions(-)
> 
> diff --git a/src/lj_memprof.c b/src/lj_memprof.c
> index 87512c3a..e4d819a0 100644
> --- a/src/lj_memprof.c
> +++ b/src/lj_memprof.c

<snipped>

> diff --git a/test/tarantool-tests/misclib-memprof-lapi.test.lua b/test/tarantool-tests/misclib-memprof-lapi.test.lua
> index b7e456e1..96864c6a 100644
> --- a/test/tarantool-tests/misclib-memprof-lapi.test.lua
> +++ b/test/tarantool-tests/misclib-memprof-lapi.test.lua
> @@ -12,7 +12,7 @@ utils.skipcond(jit.os == 'BSD', 'Disabled due to #4819')
>  local tap = require("tap")
>  
>  local test = tap.test("misc-memprof-lapi")
> -test:plan(16)
> +test:plan(17)
>  
>  jit.off()
>  jit.flush()
> @@ -81,7 +81,7 @@ local function fill_ev_type(events, symbols, event_type)
>    for _, event in pairs(events[event_type]) do
>      local addr = event.loc.addr
>      local traceno = event.loc.traceno
> -    if traceno ~= 0 then
> +    if traceno ~= 0 and symbols.trace[traceno] then

This should be moved to the commit, that changes symtab, this change
looks unrelated to this patch, but relates to previous one [1].

>        local trace_loc = symbols.trace[traceno]
>        addr = trace_loc.addr
>        ev_type[trace_loc.line] = {
> @@ -214,9 +214,17 @@ misc.memprof.stop()

<snipped>

> -- 
> 2.32.0
> 

[1]: https://lists.tarantool.org/pipermail/tarantool-patches/2021-July/024944.html

-- 
Best regards,
Sergey Kaplun