From 65622bf0e59a560a4363a9178d920303b7d4ee4c Mon Sep 17 00:00:00 2001
From: Gabriel Schulhof <gabriel.schulhof@intel.com>
Date: Sat, 14 Dec 2019 22:21:12 -0800
Subject: [PATCH] src: make --use-largepages a three-valued option

---
 doc/api/cli.md      | 9 ++++++++-
 doc/node.1          | 4 +++-
 src/node.cc         | 6 ++++--
 src/node_options.cc | 3 +++
 src/node_options.h  | 2 +-
 5 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/doc/api/cli.md b/doc/api/cli.md
index 4c549e3375760f..c2942d91931371 100644
--- a/doc/api/cli.md
+++ b/doc/api/cli.md
@@ -863,7 +863,7 @@ environment variables.
 
 See `SSL_CERT_DIR` and `SSL_CERT_FILE`.
 
-### `--use-largepages`
+### `--use-largepages=num`
 <!-- YAML
 added: REPLACEME
 -->
@@ -872,6 +872,13 @@ 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 `num`:
+* 0: No mapping will be attempted. This is the default.
+* 1: If supported by the OS, mapping will be attempted. Failure to map will be
+  ignored and will not be reported.
+* 2: If supported by the OS, mapping will be attempted. Failure to map will be
+  ignored and a message will be printed to standard error.
+
 ### `--v8-options`
 <!-- YAML
 added: v0.1.3
diff --git a/doc/node.1 b/doc/node.1
index 91912fd0c165e6..892193631813fd 100644
--- a/doc/node.1
+++ b/doc/node.1
@@ -398,10 +398,12 @@ See
 and
 .Ev SSL_CERT_FILE .
 .
-.It Fl -use-largepages
+.It Fl -use-largepages Ns = Ns Ar num
 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
+The following values are valid: 0 (do not map), 1 (map, ignore failure, and do not report it), and 2 (map, ignore failure, but report it to standard error).
 .
 .It Fl -v8-options
 Print V8 command-line options.
diff --git a/src/node.cc b/src/node.cc
index 7ba9935e4873a5..0c97a4bd4c8b49 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -984,9 +984,11 @@ InitializationResult InitializeOncePerProcess(int argc, char** argv) {
     }
   }
 
-  if (per_process::cli_options->use_largepages) {
+  if (per_process::cli_options->use_largepages == 1 ||
+      per_process::cli_options->use_largepages == 2) {
     if (node::IsLargePagesEnabled()) {
-      if (node::MapStaticCodeToLargePages() != 0) {
+      if (node::MapStaticCodeToLargePages() != 0 &&
+          per_process::cli_options->use_largepages == 2) {
         fprintf(stderr, "Reverting to default page size\n");
       }
     }
diff --git a/src/node_options.cc b/src/node_options.cc
index 1c3b3f7aa39ece..4806c6fafff3fd 100644
--- a/src/node_options.cc
+++ b/src/node_options.cc
@@ -63,6 +63,9 @@ void PerProcessOptions::CheckOptions(std::vector<std::string>* errors) {
                       "used, not both");
   }
 #endif
+  if (!(use_largepages >= 0 && use_largepages <= 2)) {
+    errors->push_back("--use-largepages must be one of 0, 1, or 2");
+  }
   per_isolate->CheckOptions(errors);
 }
 
diff --git a/src/node_options.h b/src/node_options.h
index 3db8d41c400f95..1cde4f46644770 100644
--- a/src/node_options.h
+++ b/src/node_options.h
@@ -235,7 +235,7 @@ class PerProcessOptions : public Options {
   bool force_fips_crypto = false;
 #endif
 #endif
-  bool use_largepages = false;
+  uint64_t use_largepages = 0;
 
 #ifdef NODE_REPORT
   std::vector<std::string> cmdline;