YJIT: reduce default exec-mem-size to 64MiB (#9054)

doc/yjit/yjit.md

@@ -168,7 +168,7 @@ YJIT supports all command-line options supported by upstream CRuby, but also add
 - `--yjit-call-threshold=N`: number of calls after which YJIT begins to compile a function (default 30)
 - `--yjit-cold-threshold=N`: number of global calls after which an ISEQ is considered cold and not
 compiled, lower values mean less code is compiled (default 200000)
-- `--yjit-exec-mem-size=N`: size of the executable memory block to allocate, in MiB (default 64 MiB in Ruby 3.2, 128 MiB in Ruby 3.3+)
+- `--yjit-exec-mem-size=N`: size of the executable memory block to allocate, in MiB (default 64 MiB)
 - `--yjit-stats`: print statistics after the execution of a program (incurs a run-time cost)
 - `--yjit-stats=quiet`: gather statistics while running a program but don't print them. Stats are accessible through `RubyVM::YJIT.runtime_stats`. (incurs a run-time cost)
 - `--yjit-trace-exits`: produce a Marshal dump of backtraces from specific exits. Automatically enables `--yjit-stats`

yjit/src/options.rs

@@ -81,7 +81,7 @@ pub struct Options {
 
 // Initialize the options to default values
 pub static mut OPTIONS: Options = Options {
-    exec_mem_size: 128 * 1024 * 1024,
+    exec_mem_size: 64 * 1024 * 1024,
     no_type_prop: false,
     max_versions: 4,
     num_temp_regs: 5,
@@ -104,7 +104,7 @@ static YJIT_OPTIONS: [(&str, &str); 8] = [
     ("--yjit-stats",                    "Enable collecting YJIT statistics"),
     ("--yjit-trace-exits",              "Record Ruby source location when exiting from generated code"),
     ("--yjit-trace-exits-sample-rate",  "Trace exit locations only every Nth occurrence"),
-    ("--yjit-exec-mem-size=num",        "Size of executable memory block in MiB (default: 128)"),
+    ("--yjit-exec-mem-size=num",        "Size of executable memory block in MiB (default: 64)"),
     ("--yjit-code-gc",                  "Run code GC when the code size reaches the limit"),
     ("--yjit-call-threshold=num",       "Number of calls to trigger JIT"),
     ("--yjit-cold-threshold=num",       "Global call after which ISEQs not compiled (default: 200K)"),