From 00ce6a32404e5eed66f28564eb46e6e2ccae1c0a Mon Sep 17 00:00:00 2001 From: Nimit Date: Sat, 14 Mar 2020 22:00:07 +0530 Subject: [PATCH] doc: add useful v8 option section This adds new section for v8 options and --max-old-space-size Fixes: https://github.com/nodejs/node/issues/32252 PR-URL: https://github.com/nodejs/node/pull/32262 Reviewed-By: Anna Henningsen Reviewed-By: Gireesh Punathil --- doc/api/cli.md | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/doc/api/cli.md b/doc/api/cli.md index 2f3c6a9f7da114..d323e24f3ecf96 100644 --- a/doc/api/cli.md +++ b/doc/api/cli.md @@ -1384,6 +1384,30 @@ threadpool by setting the `'UV_THREADPOOL_SIZE'` environment variable to a value greater than `4` (its current default value). For more information, see the [libuv threadpool documentation][]. +## Useful V8 options + +V8 has its own set of CLI options. Any V8 CLI option that is provided to `node` +will be passed on to V8 to handle. V8's options have _no stability guarantee_. +The V8 team themselves don't consider them to be part of their formal API, +and reserve the right to change them at any time. Likewise, they are not +covered by the Node.js stability guarantees. Many of the V8 +options are of interest only to V8 developers. Despite this, there is a small +set of V8 options that are widely applicable to Node.js, and they are +documented here: + +### `--max-old-space-size=SIZE` (in Mbytes) + +Sets the max memory size of V8's old memory section. As memory +consumption approaches the limit, V8 will spend more time on +garbage collection in an effort to free unused memory. + +On a machine with 2GB of memory, consider setting this to +1536 (1.5GB) to leave some memory for other uses and avoid swapping. + +```console +$ node --max-old-space-size=1536 index.js +``` + [`--openssl-config`]: #cli_openssl_config_file [`Buffer`]: buffer.html#buffer_class_buffer [`SlowBuffer`]: buffer.html#buffer_class_slowbuffer