Re: [Tarantool-patches] [PATCH luajit] LJ_GC64: Always snapshot functions for non-base frames.

[Maxim Kokryashkin via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

[-- Attachment #1: Type: text/plain, Size: 2683 bytes --]


Hi!
Looks good to me
 
 
--
Best regards,
Maxim Kokryashkin
 
  
>Понедельник, 12 февраля 2024, 10:40 +03:00 от Sergey Kaplun <skaplun@tarantool.org>:
> 
>Hi, folks!
>I've added several comments to the test I was bothered about.
>See them on the branch:
>https://github.com/tarantool/luajit/tree/skaplun/lj-611-always-snapshot-functions-for-non-base-frames
>
>Also, I rebased it on the tarantool/master branch.
>
>===================================================================
>diff --git a/test/tarantool-tests/lj-611-gc64-inherit-frame-slot.test.lua b/test/tarantool-tests/lj-611-gc64-inherit-frame-slot.test.lua
>index 8fc5b663..b7347267 100644
>--- a/test/tarantool-tests/lj-611-gc64-inherit-frame-slot.test.lua
>+++ b/test/tarantool-tests/lj-611-gc64-inherit-frame-slot.test.lua
>@@ -3,8 +3,9 @@ local test = tap.test('lj-611-gc64-inherit-frame-slot'):skipcond({
>   ['Test requires JIT enabled'] = not jit.status(),
> })
> 
>--- GC64: Function missing in snapshot for non-base frame
>---  https://github.com/LuaJIT/LuaJIT/issues/611
>+-- GC64: Function missing in snapshot for non-base frame.
>+-- The reproducer is generated from the fuzzer.
>+--  https://github.com/LuaJIT/LuaJIT/issues/611 .
> 
> test:plan(1)
> 
>@@ -13,7 +14,9 @@ jit.opt.start('hotloop=1', 'hotexit=1')
> local inner_counter = 0
> local SIDE_START = 1
> -- Lower frame to return from `inner()` function side trace.
>--- TODO: Give a reason for vararg func.
>+-- XXX: Use a vararg frame to prevent compilation of the function.
>+-- The FNEW bytecode is NIY for now, so this helps to avoid trace
>+-- blacklisting.
> local function lower_frame(...)
>   local inner = function()
>     if inner_counter > SIDE_START then
>@@ -21,10 +24,18 @@ local function lower_frame(...)
>     end
>     inner_counter = inner_counter + 1
>   end
>+ -- XXX: We need to return to the lower frame (to the same
>+ -- function) several times to produce the necessary side traces.
>+ -- See `jit.dump()` for the details.
>   inner(..., inner(inner()))
> end
> 
> -- Compile `inner()` function.
>+-- XXX: We need at least 3 calls to create several function
>+-- objects from the prototype of the `inner()` function and hit
>+-- the `PROTO_CLC_POLY` limit, so the side traces stop spawning.
>+-- See also:
>+--  https://github.com/tarantool/tarantool/wiki/LuaJIT-function-inlining .
> lower_frame()
> lower_frame()
> -- Compile hotexit.
>===================================================================
>
>Can you please verify that these changes are OK for you, so we can
>proceed with the backporting of the patch?
>
>--
>Best regards,
>Sergey Kaplun
 

[-- Attachment #2: Type: text/html, Size: 3803 bytes --]