src: make --use-largepages a runtime option

Moves the option that instructs Node.js to-remap its static code to large pages from a configure-time option to a runtime option. This should make it easy to assess the performance impact of such a change without having to custom-build. Backport-PR-URL: #31063 PR-URL: #30954 Reviewed-By: Ben Noordhuis <[email protected]> Reviewed-By: David Carlier <[email protected]> Reviewed-By: David Carlier <[email protected]> Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Gireesh Punathil <[email protected]> Reviewed-By: Denys Otrishko <[email protected]> Co-authored-by: David Carlier <[email protected]>

Author: 2 people

configure.py

@@ -398,17 +398,6 @@
 dest='with_etw',
 help='build with ETW (default is true on Windows)')
 
-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')
-
-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')
-
 intl_optgroup.add_option('--with-intl',
 action='store',
 dest='with_intl',
@@ -1041,28 +1030,6 @@ def configure_node(o):
 else:
 o['variables']['node_use_dtrace'] ='false'
 
-ifoptions.node_use_large_pagesandnotflavorin ('linux', 'freebsd', 'mac'):
-raiseException(
-'Large pages are supported only on Linux, FreeBSD and MacOS Systems.')
-ifoptions.node_use_large_pagesandflavorin ('linux', 'freebsd', 'mac'):
-ifoptions.sharedoroptions.enable_static:
-raiseException(
-'Large pages are supported only while creating node executable.')
-iftarget_arch!="x64":
-raiseException(
-'Large pages are supported only x64 platform.')
-ifflavor=='mac':
-info('macOS server with 32GB or more is recommended')
-ifflavor=='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]
-ifKERNEL_VERSION<"2.6.38"andflavor=='linux':
-raiseException(
-'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)
-
 ifoptions.no_ifaddrs:
 o['defines'] += ['SUNOS_NO_IFADDRS']
 

doc/api/cli.md

@@ -843,6 +843,22 @@ 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
@@ -1096,6 +1112,7 @@ 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

@@ -377,6 +377,16 @@ See
 and
 .EvSSL_CERT_FILE .
 .
+.ItFl-use-largepagesNs=NsArmode
+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
+.Armode
+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).
+.
 .ItFl-v8-options
 Print V8 command-line options.
 .

node.gyp

@@ -824,10 +824,9 @@
  }],
  ],
  }],
- [ 'node_use_large_pages=="true" and OS in "linux freebsd mac"',{
+ [ 'OS in "linux freebsd mac" and '
+'target_arch=="x64"',{
 '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'

node.gypi

@@ -302,17 +302,15 @@
  }],
  [ 'OS=="linux" and '
 'target_arch=="x64" and '
-'node_use_large_pages=="true" and '
-'node_use_large_pages_script_lld=="false"',{
+'llvm_version=="0.0"',{
 '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"',{
+'llvm_version!="0.0"',{
 'ldflags': [
 '-Wl,-T',
 '<!(realpath src/large_pages/ld.implicit.script.lld)',

src/large_pages/node_large_page.cc

@@ -62,7 +62,7 @@
 // Map a new area and copy the original code there
 // Use mmap using the start address with MAP_FIXED so we get exactly the
 // same virtual address
-// Use madvise with MADV_HUGE_PAGE to use Anonymous 2M Pages
+// Use madvise with MADV_HUGEPAGE to use Anonymous 2M Pages
 // If successful copy the code there and unmap the original region.
 
 externchar __nodetext;
@@ -308,7 +308,7 @@ static bool IsSuperPagesEnabled(){
 // a. map a new area and copy the original code there
 // b. mmap using the start address with MAP_FIXED so we get exactly
 // the same virtual address (except on macOS).
-// c. madvise with MADV_HUGE_PAGE
+// c. madvise with MADV_HUGEPAGE
 // d. If successful copy the code there and unmap the original region
 int
 #if !defined(__APPLE__)
@@ -333,9 +333,6 @@ MoveTextRegionToLargePages(const text_region& r){
 PrintSystemError(errno);
 return -1;
  }
- OnScopeLeave munmap_on_return([nmem, size](){
-if (-1 == munmap(nmem, size)) PrintSystemError(errno);
- });
 
 memcpy(nmem, r.from, size);
 
@@ -352,13 +349,14 @@ MoveTextRegionToLargePages(const text_region& r){
 return -1;
  }
 
- ret = madvise(tmem, size, MADV_HUGEPAGE);
+ ret = madvise(tmem, size, 14/*MADV_HUGEPAGE*/);
 if (ret == -1){
 PrintSystemError(errno);
  ret = munmap(tmem, size);
 if (ret == -1){
 PrintSystemError(errno);
  }
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return -1;
  }
 memcpy(start, nmem, size);
@@ -369,6 +367,7 @@ MoveTextRegionToLargePages(const text_region& r){
  MAP_ALIGNED_SUPER, -1 , 0);
 if (tmem == MAP_FAILED){
 PrintSystemError(errno);
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return -1;
  }
 #elif defined(__APPLE__)
@@ -383,6 +382,7 @@ MoveTextRegionToLargePages(const text_region& r){
  VM_FLAGS_SUPERPAGE_SIZE_2MB, 0);
 if (tmem == MAP_FAILED){
 PrintSystemError(errno);
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return -1;
  }
 memcpy(tmem, nmem, size);
@@ -393,6 +393,7 @@ MoveTextRegionToLargePages(const text_region& r){
 if (ret == -1){
 PrintSystemError(errno);
  }
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return -1;
  }
 memcpy(start, tmem, size);
@@ -405,8 +406,10 @@ MoveTextRegionToLargePages(const text_region& r){
 if (ret == -1){
 PrintSystemError(errno);
  }
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return -1;
  }
+if (-1 == munmap(nmem, size)) PrintSystemError(errno);
 return ret;
 }
 
@@ -418,12 +421,12 @@ int MapStaticCodeToLargePages(){
 return -1;
  }
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
 if (r.from > reinterpret_cast<void*>(&MoveTextRegionToLargePages))
 returnMoveTextRegionToLargePages(r);
 
 return -1;
-#elif defined(__FreeBSD__) || defined(__APPLE__)
+#elif defined(__APPLE__)
 returnMoveTextRegionToLargePages(r);
 #endif
 }

src/node.cc

@@ -64,9 +64,7 @@
 #include"inspector/worker_inspector.h"// ParentInspectorHandle
 #endif
 
-#ifdef NODE_ENABLE_LARGE_CODE_PAGES
 #include"large_pages/node_large_page.h"
-#endif
 
 #ifdef NODE_REPORT
 #include"node_report.h"
@@ -887,14 +885,6 @@ InitializationResult InitializeOncePerProcess(int argc, char** argv){
 
 CHECK_GT(argc, 0);
 
-#ifdef NODE_ENABLE_LARGE_CODE_PAGES
-if (node::IsLargePagesEnabled()){
-if (node::MapStaticCodeToLargePages() != 0){
-fprintf(stderr, "Reverting to default page size\n");
- }
- }
-#endif
-
 // Hack around with the argv pointer. Used for process.title = "blah".
  argv = uv_setup_args(argc, argv);
 
@@ -914,6 +904,26 @@ InitializationResult InitializeOncePerProcess(int argc, char** argv){
  }
  }
 
+#if defined(NODE_ENABLE_LARGE_CODE_PAGES) && NODE_ENABLE_LARGE_CODE_PAGES
+if (per_process::cli_options->use_largepages == "on" ||
+ per_process::cli_options->use_largepages == "silent"){
+if (node::IsLargePagesEnabled()){
+if (node::MapStaticCodeToLargePages() != 0 &&
+ per_process::cli_options->use_largepages != "silent"){
+fprintf(stderr,
+"Mapping code to large pages failed. Reverting to default page "
+"size.\n");
+ }
+ } elseif (per_process::cli_options->use_largepages != "silent"){
+fprintf(stderr, "Large pages are not enabled.\n");
+ }
+ }
+#else
+if (per_process::cli_options->use_largepages == "on"){
+fprintf(stderr, "Mapping to large pages is not supported.\n");
+ }
+#endif// NODE_ENABLE_LARGE_CODE_PAGES
+
 if (per_process::cli_options->print_version){
 printf("%s\n", NODE_VERSION);
  result.exit_code = 0;

src/node_options.cc

@@ -63,6 +63,11 @@ void PerProcessOptions::CheckOptions(std::vector<std::string>* errors){
 "used, not both");
  }
 #endif
+if (use_largepages != "off" &&
+ use_largepages != "on" &&
+ use_largepages != "silent"){
+ errors->push_back("invalid value for --use-largepages");
+ }
  per_isolate->CheckOptions(errors);
 }
 
@@ -749,6 +754,10 @@ PerProcessOptionsParser::PerProcessOptionsParser(
 kAllowedInEnvironment);
 #endif
 #endif
+AddOption("--use-largepages",
+"Map the Node.js static code to large pages",
+ &PerProcessOptions::use_largepages,
+kAllowedInEnvironment);
 
 // v12.x backwards compat flags removed in V8 7.9.
 AddOption("--fast_calls_with_arguments_mismatches", "", NoOp{});

src/node_options.h

@@ -233,6 +233,7 @@ class PerProcessOptions : public Options{
 bool force_fips_crypto = false;
 #endif
 #endif
+ std::string use_largepages = "off";
 
 #ifdef NODE_REPORT
  std::vector<std::string> cmdline;

test/parallel/test-startup-large-pages.js

@@ -0,0 +1,29 @@
+'use strict';
+
+// Make sure that Node.js runs correctly with the --use-largepages option.
+
+require('../common');
+constassert=require('assert');
+const{ spawnSync }=require('child_process');
+
+{
+constchild=spawnSync(process.execPath,
+['--use-largepages=on','-p','42']);
+conststdout=child.stdout.toString().match(/\S+/g);
+assert.strictEqual(child.status,0);
+assert.strictEqual(child.signal,null);
+assert.strictEqual(stdout.length,1);
+assert.strictEqual(stdout[0],'42');
+}
+
+{
+constchild=spawnSync(process.execPath,
+['--use-largepages=xyzzy','-p','42']);
+assert.strictEqual(child.status,9);
+assert.strictEqual(child.signal,null);
+assert.strictEqual(child.stderr.toString().match(/\S+/g).slice(1).join(' '),
+'invalid value for --use-largepages');
+}
+
+// TODO(gabrielschulhof): Make assertions about the stderr, which may or may not
+// contain a message indicating that mapping to large pages has failed.