Large Page Support for Code Issue: 16198

configure

@@ -392,6 +392,12 @@ parser.add_option('--with-etw',
     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 (enabled only for Linux).' +
+         '(Needs Linux kernel >= 2.6.38 with Transparent Huge pages enabled)')
+
 intl_optgroup.add_option('--with-intl',
     action='store',
     dest='with_intl',
@@ -936,6 +942,9 @@ def configure_node(o):
   else:
     o['variables']['node_use_dtrace'] = 'false'
 
+  use_large_pages = (flavor == 'linux' and options.node_use_large_pages)
+  o['variables']['node_use_large_pages'] = b(use_large_pages)
+
   if options.no_ifaddrs:
     o['defines'] += ['SUNOS_NO_IFADDRS']
 

ld.implicit.script

@@ -0,0 +1,8 @@
+  SECTIONS {
+  .lpstub            : { *(.lpstub) }
+  }
+  PROVIDE (__nodetext = .);
+  PROVIDE (_nodetext = .);
+  PROVIDE (nodetext = .);
+  INSERT BEFORE .text;
+

node.gyp

@@ -594,6 +594,19 @@
             'src/tls_wrap.h'
           ],
         }],
+        [ 'node_use_large_pages=="true"', {
+          'defines': [ 'NODE_ENABLE_LARGE_CODE_PAGES=1' ],
+          # The current implementation of Large Pages is under Linux.
+          # Other implementations are possible but not currently supported.
+          #
+          'conditions': [
+            [ 'OS=="linux"', {
+              'sources': [
+                'src/node_large_page.cc'
+              ],
+            }],
+          ]
+        } ],
       ],
     },
     {

node.gypi

@@ -188,7 +188,18 @@
             },
           },
           'conditions': [
-            ['OS!="aix" and node_shared=="false"', {
+            ['OS=="linux" and node_shared=="false" \
+              and target_arch=="x64" \
+              and node_use_large_pages=="true"', {
+              'ldflags': [
+                 '-Wl,-T <(PRODUCT_DIR)/../../ld.implicit.script',
+                 '-Wl,--whole-archive,<(obj_dir)/deps/uv/<(STATIC_LIB_PREFIX)'
+                    'uv<(STATIC_LIB_SUFFIX)',
+                '-Wl,--no-whole-archive',
+             ]
+            }],
+            ['OS!="aix" and node_shared=="false" \
+              and node_use_large_pages=="false"', {
               'ldflags': [
                 '-Wl,--whole-archive,<(obj_dir)/deps/uv/<(STATIC_LIB_PREFIX)'
                     'uv<(STATIC_LIB_SUFFIX)',

src/node.cc

@@ -70,6 +70,7 @@
 #ifdef NODE_ENABLE_VTUNE_PROFILING
 #include "../deps/v8/src/third_party/vtune/v8-vtune.h"
 #endif
+#include "node_large_page.h"
 
 #include <errno.h>
 #include <fcntl.h>  // _O_RDWR
@@ -4377,6 +4378,15 @@ int Start(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);
 

src/node_large_page.cc

@@ -0,0 +1,253 @@
+// Copyright (C) 2018 Intel Corporation
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom
+// the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
+// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
+// OR OTHER DEALINGS IN THE SOFTWARE.
+//
+// SPDX-License-Identifier: MIT
+
+#include <errno.h>
+#include <fcntl.h>  // _O_RDWR
+#include <limits.h>  // PATH_MAX
+#include <locale.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include <string>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+
+// The functions in this file map the text segment of node into 2M pages.
+// The algorithm is simple
+// 1. Find the text region of node binary in memory
+//    Examine the /proc/self/maps to determine the currently mapped text
+//    region and obtain the start and end
+//    Modify the start to point to the very beginning of node text segment
+//    (from variable nodetext setup in ld.script)
+//    Align the address of start and end to Large Page Boundaries
+//
+// 2. Move the text region to large pages
+//    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
+//    If successful copy the code there and unmap the original region.
+
+extern char __executable_start;
+extern char __etext;
+extern char __nodetext;
+
+namespace node {
+#define ALIGN(x, a)           (((x) + (a) - 1) & ~((a) - 1))
+#define PAGE_ALIGN_UP(x, a)   ALIGN(x, a)
+#define PAGE_ALIGN_DOWN(x, a) ((x) & ~((a) - 1))
+
+struct text_region {
+  char* from;
+  char* to;
+  int   total_hugepages;
+  bool  found_text_region;
+};
+
+static void PrintSystemError(int error) {
+  fprintf(stderr, "Hugepages WARNING: %s\n", strerror(error));
+  return;
+}
+
+//  The format of the maps file is the following
+//  address           perms offset  dev   inode       pathname
+//  00400000-00452000 r-xp 00000000 08:02 173521      /usr/bin/dbus-daemon
+
+static struct text_region FindNodeTextRegion() {
+  std::ifstream ifs;
+  std::string map_line;
+  std::string permission;
+  char dash;
+  int64_t  start, end;
+  const size_t hps = 2L * 1024 * 1024;
+  struct text_region nregion;
+
+  nregion.found_text_region = false;
+
+  ifs.open("/proc/self/maps");
+  if (!ifs) {
+    fprintf(stderr, "Could not open /proc/self/maps\n");
+    return nregion;
+  }
+  std::getline(ifs, map_line);
+  std::istringstream iss(map_line);
+  ifs.close();
+
+  iss >> std::hex >> start;
+  iss >> dash;
+  iss >> std::hex >> end;
+  iss >> permission;
+
+  if (permission.compare("r-xp") == 0) {
+    start = reinterpret_cast<unsigned int64_t>(&__nodetext);
+    char* from = reinterpret_cast<char *>PAGE_ALIGN_UP(start, hps);
+    char* to = reinterpret_cast<char *>PAGE_ALIGN_DOWN(end, hps);
+
+    if (from < to) {
+      size_t size = to - from;
+      nregion.found_text_region = true;
+      nregion.from = from;
+      nregion.to = to;
+      nregion.total_hugepages = size / hps;
+    }
+  }
+
+  return nregion;
+}
+
+static bool IsTransparentHugePagesEnabled() {
+  std::ifstream ifs;
+
+  ifs.open("/sys/kernel/mm/transparent_hugepage/enabled");
+  if (!ifs) {
+    fprintf(stderr, "Could not open file: " \
+                     "/sys/kernel/mm/transparent_hugepage/enabled\n");
+    return false;
+  }
+
+  std::string always, madvise, never;
+  if (ifs.is_open()) {
+    while (ifs >> always >> madvise >> never) {}
+  }
+
+  int ret_status = false;
+
+  if (always.compare("[always]") == 0)
+    ret_status = true;
+  else if (madvise.compare("[madvise]") == 0)
+    ret_status = true;
+  else if (never.compare("[never]") == 0)
+    ret_status = false;
+
+  ifs.close();
+  return ret_status;
+}
+
+//  Moving the text region to large pages. We need to be very careful.
+//  a) This function itself should not be moved.
+//     We use a gcc option to put it outside the ".text" section
+//  b) This function should not call any function(s) that might be moved.
+//    1. map a new area and copy the original code there
+//    2. mmap using the start address with MAP_FIXED so we get exactly
+//       the same virtual address
+//    3. madvise with MADV_HUGE_PAGE
+//    3. If successful copy the code there and unmap the original region
+int
+__attribute__((__section__(".lpstub")))
+__attribute__((__aligned__(2 * 1024 * 1024)))
+__attribute__((__noinline__))
+__attribute__((__optimize__("2")))
+MoveTextRegionToLargePages(struct text_region r) {
+  void* nmem = nullptr;
+  void* tmem = nullptr;
+  int ret = 0;
+
+  size_t size = r.to - r.from;
+  void* start = r.from;
+
+  // Allocate temporary region preparing for copy
+  nmem = mmap(nullptr, size,
+              PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (nmem == MAP_FAILED) {
+    PrintSystemError(errno);
+    return -1;
+  }
+
+  memcpy(nmem, r.from, size);
+
+// We already know the original page is r-xp
+// (PROT_READ, PROT_EXEC, MAP_PRIVATE)
+// We want PROT_WRITE because we are writing into it.
+// We want it at the fixed address and we use MAP_FIXED.
+  tmem = mmap(start, size,
+              PROT_READ | PROT_WRITE | PROT_EXEC,
+              MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1 , 0);
+  if (tmem == MAP_FAILED) {
+    PrintSystemError(errno);
+    munmap(nmem, size);
+    return -1;
+  }
+
+  ret = madvise(tmem, size, MADV_HUGEPAGE);
+  if (ret == -1) {
+    PrintSystemError(errno);
+    ret = munmap(tmem, size);
+    if (ret == -1) {
+      PrintSystemError(errno);
+    }
+    ret = munmap(nmem, size);
+    if (ret == -1) {
+      PrintSystemError(errno);
+    }
+
+    return -1;
+  }
+
+  memcpy(start, nmem, size);
+  ret = mprotect(start, size, PROT_READ | PROT_EXEC);
+  if (ret == -1) {
+    PrintSystemError(errno);
+    ret = munmap(tmem, size);
+    if (ret == -1) {
+      PrintSystemError(errno);
+    }
+    ret = munmap(nmem, size);
+    if (ret == -1) {
+      PrintSystemError(errno);
+    }
+    return -1;
+  }
+
+  // Release the old/temporary mapped region
+  ret = munmap(nmem, size);
+  if (ret == -1) {
+    PrintSystemError(errno);
+  }
+
+  return ret;
+}
+
+// This is the primary API called from main
+int MapStaticCodeToLargePages() {
+  struct text_region r = FindNodeTextRegion();
+  if (r.found_text_region == false) {
+    fprintf(stderr, "Hugepages WARNING: failed to find text region \n");
+    return -1;
+  }
+
+  if (r.from > reinterpret_cast<void *> (&MoveTextRegionToLargePages))
+    return MoveTextRegionToLargePages(r);
+
+  return -1;
+}
+
+bool  IsLargePagesEnabled() {
+  return IsTransparentHugePagesEnabled();
+}
+
+}  // namespace node

src/node_large_page.h

@@ -0,0 +1,36 @@
+// Copyright (C) 2018 Intel Corporation
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom
+// the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
+// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
+// OR OTHER DEALINGS IN THE SOFTWARE.
+//
+// SPDX-License-Identifier: MIT
+
+#ifndef SRC_NODE_LARGE_PAGE_H_
+#define SRC_NODE_LARGE_PAGE_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+
+namespace node {
+  bool IsLargePagesEnabled();
+  int MapStaticCodeToLargePages();
+}  // namespace node
+
+#endif  // NODE_WANT_INTERNALS
+#endif  // SRC_NODE_LARGE_PAGE_H_
+