[v12.x] Backport large pages asm to v12.x

configure.py

@@ -427,13 +427,12 @@
 parser.add_option('--use-largepages',
     action='store_true',
     dest='node_use_large_pages',
-    help='build with Large Pages support. This feature is supported only on Linux kernel' +
-         '>= 2.6.38 with Transparent Huge pages enabled and FreeBSD')
+    help='This option has no effect. --use-largepages is now a runtime option.')
 
 parser.add_option('--use-largepages-script-lld',
     action='store_true',
     dest='node_use_large_pages_script_lld',
-    help='link against the LLVM ld linker script. Implies -fuse-ld=lld in the linker flags')
+    help='This option has no effect. --use-largepages is now a runtime option.')
 
 intl_optgroup.add_option('--with-intl',
     action='store',
@@ -1092,27 +1091,12 @@ def configure_node(o):
   else:
     o['variables']['node_use_dtrace'] = 'false'
 
-  if options.node_use_large_pages and not flavor in ('linux', 'freebsd', 'mac'):
-    raise Exception(
-      'Large pages are supported only on Linux, FreeBSD and MacOS Systems.')
-  if options.node_use_large_pages and flavor in ('linux', 'freebsd', 'mac'):
-    if options.shared or options.enable_static:
-      raise Exception(
-        'Large pages are supported only while creating node executable.')
-    if target_arch!="x64":
-      raise Exception(
-        'Large pages are supported only x64 platform.')
-    if flavor == 'mac':
-      info('macOS server with 32GB or more is recommended')
-    if flavor == 'linux':
-      # Example full version string: 2.6.32-696.28.1.el6.x86_64
-      FULL_KERNEL_VERSION=os.uname()[2]
-      KERNEL_VERSION=FULL_KERNEL_VERSION.split('-')[0]
-      if KERNEL_VERSION < "2.6.38" and flavor == 'linux':
-        raise Exception(
-          'Large pages need Linux kernel version >= 2.6.38')
-  o['variables']['node_use_large_pages'] = b(options.node_use_large_pages)
-  o['variables']['node_use_large_pages_script_lld'] = b(options.node_use_large_pages_script_lld)
+  if options.node_use_large_pages or options.node_use_large_pages_script_lld:
+    warn('''The `--use-largepages` and `--use-largepages-script-lld` options
+         have no effect during build time. Support for mapping to large pages is
+         now a runtime option of Node.js. Run `node --use-largepages` or add
+         `--use-largepages` to the `NODE_OPTIONS` environment variable once
+         Node.js is built to enable mapping to large pages.''')
 
   if options.no_ifaddrs:
     o['defines'] += ['SUNOS_NO_IFADDRS']

doc/api/cli.md

@@ -900,6 +900,22 @@ environment variables.
 
 See `SSL_CERT_DIR` and `SSL_CERT_FILE`.
 
+### `--use-largepages=mode`
+<!-- YAML
+added: REPLACEME
+-->
+
+Re-map the Node.js static code to large memory pages at startup. If supported on
+the target system, this will cause the Node.js static code to be moved onto 2
+MiB pages instead of 4 KiB pages.
+
+The following values are valid for `mode`:
+* `off`: No mapping will be attempted. This is the default.
+* `on`: If supported by the OS, mapping will be attempted. Failure to map will
+  be ignored and a message will be printed to standard error.
+* `silent`: If supported by the OS, mapping will be attempted. Failure to map
+  will be ignored and will not be reported.
+
 ### `--v8-options`
 <!-- YAML
 added: v0.1.3
@@ -1157,6 +1173,7 @@ Node.js options that are allowed are:
 * `--track-heap-objects`
 * `--unhandled-rejections`
 * `--use-bundled-ca`
+* `--use-largepages`
 * `--use-openssl-ca`
 * `--v8-pool-size`
 * `--zero-fill-buffers`

doc/node.1

@@ -432,6 +432,16 @@ See
 and
 .Ev SSL_CERT_FILE .
 .
+.It Fl -use-largepages Ns = Ns Ar mode
+Re-map the Node.js static code to large memory pages at startup. If supported on
+the target system, this will cause the Node.js static code to be moved onto 2
+MiB pages instead of 4 KiB pages.
+.Pp
+.Ar mode
+must have one of the following values:
+`off` (the default value, meaning do not map), `on` (map and ignore failure,
+reporting it to stderr), or `silent` (map and silently ignore failure).
+.
 .It Fl -v8-options
 Print V8 command-line options.
 .

node.gyp

@@ -244,6 +244,11 @@
     'node_mksnapshot_exec': '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)node_mksnapshot<(EXECUTABLE_SUFFIX)',
     'mkcodecache_exec': '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)mkcodecache<(EXECUTABLE_SUFFIX)',
     'conditions': [
+      ['GENERATOR == "ninja"', {
+        'node_text_start_object_path': 'src/large_pages/node_text_start.node_text_start.o'
+      }, {
+        'node_text_start_object_path': 'node_text_start/src/large_pages/node_text_start.o'
+      }],
       [ 'node_shared=="true"', {
         'node_target_type%': 'shared_library',
         'conditions': [
@@ -307,6 +312,19 @@
   },
 
   'targets': [
+    {
+      'target_name': 'node_text_start',
+      'type': 'none',
+      'conditions': [
+        [ 'OS=="linux" and '
+          'target_arch=="x64"', {
+          'type': 'static_library',
+          'sources': [
+            'src/large_pages/node_text_start.S'
+          ]
+        }],
+      ]
+    },
     {
       'target_name': '<(node_core_target_name)',
       'type': 'executable',
@@ -492,6 +510,13 @@
             'src/node_snapshot_stub.cc'
           ],
         }],
+        [ 'OS=="linux" and '
+          'target_arch=="x64"', {
+          'dependencies': [ 'node_text_start' ],
+          'ldflags+': [
+            '<(obj_dir)/<(node_text_start_object_path)'
+          ]
+        }],
       ],
     }, # node_core_target_name
     {
@@ -617,6 +642,8 @@
         'src/histogram-inl.h',
         'src/http_parser_adaptor.h',
         'src/js_stream.h',
+        'src/large_pages/node_large_page.cc',
+        'src/large_pages/node_large_page.h'
         'src/memory_tracker.h',
         'src/memory_tracker-inl.h',
         'src/module_wrap.h',
@@ -846,14 +873,10 @@
             }],
           ],
         }],
-        [ 'node_use_large_pages=="true" and OS in "linux freebsd mac"', {
+        [ 'OS in "linux freebsd mac" and '
+          'target_arch=="x64" and '
+          'node_target_type=="executable"', {
           'defines': [ 'NODE_ENABLE_LARGE_CODE_PAGES=1' ],
-          # The current implementation of Large Pages is under Linux.
-          # Other implementations are possible but not currently supported.
-          'sources': [
-            'src/large_pages/node_large_page.cc',
-            'src/large_pages/node_large_page.h'
-          ],
         }],
         [ 'use_openssl_def==1', {
           # TODO(bnoordhuis) Make all platforms export the same list of symbols.

node.gypi

@@ -317,24 +317,6 @@
       'ldflags': [ '-Wl,-z,relro',
                    '-Wl,-z,now' ]
     }],
-    [ 'OS=="linux" and '
-      'target_arch=="x64" and '
-      'node_use_large_pages=="true" and '
-      'node_use_large_pages_script_lld=="false"', {
-      'ldflags': [
-        '-Wl,-T',
-        '<!(realpath src/large_pages/ld.implicit.script)',
-      ]
-    }],
-    [ 'OS=="linux" and '
-      'target_arch=="x64" and '
-      'node_use_large_pages=="true" and '
-      'node_use_large_pages_script_lld=="true"', {
-      'ldflags': [
-        '-Wl,-T',
-        '<!(realpath src/large_pages/ld.implicit.script.lld)',
-      ]
-    }],
     [ 'node_use_openssl=="true"', {
       'defines': [ 'HAVE_OPENSSL=1' ],
       'conditions': [