Hi! I have one more question:
How should we properly test the behavior of profiler recording allocations from traces?
Now I can write test which roughly estimates number of allocations in loop:
| local function payload()
| -- Preallocate table to avoid table array part reallocations.
| local _ = table_new(100, 0)
| -- Want too see 100 objects here.
| for i = 1, 100 do
| -- Try to avoid crossing with "test" module objects.
| _[i] = "memprof-str-"..i
| end
| _ = nil
| -- VMSTATE == GC, reported as INTERNAL.
| collectgarbage()
| end
| jit.on()
| symbols, events = `run_payload_under_memprof_and_parse`()
| alloc = `get_all_alloc_events`(symbols, events)
| test:ok(alloc[`line_where_loop_starts`].num > `some_guaranteed_number`)
But I think it will be great if we could replace > sign with ==. The problem is we cannot guarantee
constant number of allocations in the loop: on the most of platforms with `jit.opt.start(‘’hotloop=1’’, ‘’-sink’’)`
I get 97 allocations in 100-iteration loop, as we spend some iterations to compile the trace. But on freebsd,
for example, I get 24 allocations.
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Best regards,
Mikhail Shishatskiy
Среда, 21 июля 2021, 14:48 +03:00 от Sergey Kaplun <skaplun@tarantool.org>:
Hi! Thanks for the patch!
Please consider my comments below.
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Best regards,
Sergey Kaplun