From 93ec7ab8bd619f6870c1e980f35d74dcfadf14df Mon Sep 17 00:00:00 2001 From: Keyhan Vakil Date: Thu, 4 Jan 2024 07:30:24 +0000 Subject: [PATCH] v8: enable maglev on supported architectures Enable V8's new maglev compiler by default on supported architectures. This brings modest performance improvements for short-lived workloads like CLI programs (see the linked issue) and brings Node.js's configuration slightly closer to Google Chrome's. I marked this change as semver-major because Maglev can theoretically cause performance regressions, although I haven't seen an example of that in the (somewhat limited) benchmarking I've done. **Notable Change Summary:** V8's Maglev Compiler is now enabled by default on supported architectures (https://v8.dev/blog/maglev). Maglev improves CPU performance for short-lived CLI programs by around 8%. Fixes: https://github.com/nodejs/node/issues/50690 --- configure.py | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/configure.py b/configure.py index 5e014bf7a75e2a..743101c9ea4ee9 100755 --- a/configure.py +++ b/configure.py @@ -56,6 +56,7 @@ valid_mips_float_abi = ('soft', 'hard') valid_intl_modes = ('none', 'small-icu', 'full-icu', 'system-icu') icu_versions = json.loads((tools_path / 'icu' / 'icu_versions.json').read_text(encoding='utf-8')) +maglev_enabled_architectures = ('x64', 'arm', 'arm64') shareable_builtins = {'cjs_module_lexer/lexer': 'deps/cjs-module-lexer/lexer.js', 'cjs_module_lexer/dist/lexer': 'deps/cjs-module-lexer/dist/lexer.js', @@ -812,11 +813,13 @@ help='Enable V8 transparent hugepage support. This feature is only '+ 'available on Linux platform.') -parser.add_argument('--v8-enable-maglev', +maglev_enabled_by_default_help = f"(Maglev is enabled by default on {','.join(maglev_enabled_architectures)})" + +parser.add_argument('--v8-disable-maglev', action='store_true', - dest='v8_enable_maglev', + dest='v8_disable_maglev', default=None, - help='Enable V8 Maglev compiler. Not available on all platforms.') + help=f"Disable V8's Maglev compiler. {maglev_enabled_by_default_help}") parser.add_argument('--v8-enable-short-builtin-calls', action='store_true', @@ -1498,7 +1501,8 @@ def configure_v8(o): o['variables']['v8_random_seed'] = 0 # Use a random seed for hash tables. o['variables']['v8_promise_internal_field_count'] = 1 # Add internal field to promises for async hooks. o['variables']['v8_use_siphash'] = 0 if options.without_siphash else 1 - o['variables']['v8_enable_maglev'] = 1 if options.v8_enable_maglev else 0 + o['variables']['v8_enable_maglev'] = B(not options.v8_disable_maglev and + o['variables']['target_arch'] in maglev_enabled_architectures) o['variables']['v8_enable_pointer_compression'] = 1 if options.enable_pointer_compression else 0 o['variables']['v8_enable_31bit_smis_on_64bit_arch'] = 1 if options.enable_pointer_compression else 0 o['variables']['v8_enable_shared_ro_heap'] = 0 if options.enable_pointer_compression or options.disable_shared_ro_heap else 1