ergo.c revision 4680
4632N/A/*
4632N/A * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
4632N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4632N/A *
4632N/A * This code is free software; you can redistribute it and/or modify it
4632N/A * under the terms of the GNU General Public License version 2 only, as
4632N/A * published by the Free Software Foundation. Oracle designates this
4632N/A * particular file as subject to the "Classpath" exception as provided
4632N/A * by Oracle in the LICENSE file that accompanied this code.
4632N/A *
4632N/A * This code is distributed in the hope that it will be useful, but WITHOUT
4632N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
4632N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
4632N/A * version 2 for more details (a copy is included in the LICENSE file that
4632N/A * accompanied this code).
4632N/A *
4632N/A * You should have received a copy of the GNU General Public License version
4632N/A * 2 along with this work; if not, write to the Free Software Foundation,
4632N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
4632N/A *
4632N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
4632N/A * or visit www.oracle.com if you need additional information or have any
4632N/A * questions.
4632N/A */
4632N/A
4632N/A/* This file houses the common methods for VM ergonomics the platforms
4632N/A * are split into ergo_sparc and ergo_x86, and they could be split more
4632N/A * in the future if required. The following comments are not entirely
4632N/A * true after bifurcation of the platform specific files.
4632N/A */
4632N/A
4632N/A/*
4632N/A * The following methods (down to ServerClassMachine()) answer
4632N/A * the question about whether a machine is a "server-class"
4632N/A * machine. A server-class machine is loosely defined as one
4632N/A * with 2 or more processors and 2 gigabytes or more physical
4632N/A * memory. The definition of a processor is a physical package,
4632N/A * not a hyperthreaded chip masquerading as a multi-processor.
4632N/A * The definition of memory is also somewhat fuzzy, since x86
4632N/A * machines seem not to report all the memory in their DIMMs, we
4632N/A * think because of memory mapping of graphics cards, etc.
4632N/A *
4632N/A * This code is somewhat more confused with #ifdef's than we'd
4632N/A * like because this file is used by both Solaris and Linux
4632N/A * platforms, and so needs to be parameterized for SPARC and
4632N/A * i586 hardware. The other Linux platforms (amd64 and ia64)
4632N/A * don't even ask this question, because they only come with
4632N/A * server JVMs.
4632N/A */
4632N/A
4632N/A#include "ergo.h"
4632N/A
4632N/A/* Dispatch to the platform-specific definition of "server-class" */
4632N/Ajboolean
4632N/AServerClassMachine(void) {
4632N/A jboolean result;
4632N/A switch(GetErgoPolicy()) {
4632N/A case NEVER_SERVER_CLASS:
4632N/A return JNI_FALSE;
4632N/A case ALWAYS_SERVER_CLASS:
4632N/A return JNI_TRUE;
4632N/A default:
4632N/A result = ServerClassMachineImpl();
4632N/A JLI_TraceLauncher("ServerClassMachine: returns default value of %s\n",
4632N/A (result == JNI_TRUE ? "true" : "false"));
4632N/A return result;
4632N/A }
4632N/A}
4632N/A
#ifdef USE_GENERIC_ERGO
/* Ask the OS how many processors there are. */
static unsigned long
physical_processors(void) {
const unsigned long sys_processors = sysconf(_SC_NPROCESSORS_CONF);
JLI_TraceLauncher("sysconf(_SC_NPROCESSORS_CONF): %lu\n", sys_processors);
return sys_processors;
}
jboolean
ServerClassMachineImpl(void) {
jboolean result = JNI_FALSE;
/* How big is a server class machine? */
const unsigned long server_processors = 2UL;
const uint64_t server_memory = 2UL * GB;
const uint64_t actual_memory = physical_memory();
/* Is this a server class machine? */
if (actual_memory >= server_memory) {
const unsigned long actual_processors = physical_processors();
if (actual_processors >= server_processors) {
result = JNI_TRUE;
}
}
JLI_TraceLauncher("unix_" LIBARCHNAME "_ServerClassMachine: %s\n",
(result == JNI_TRUE ? "JNI_TRUE" : "JNI_FALSE"));
return result;
}
#endif
/* Compute physical memory by asking the OS */
uint64_t
physical_memory(void) {
const uint64_t pages = (uint64_t) sysconf(_SC_PHYS_PAGES);
const uint64_t page_size = (uint64_t) sysconf(_SC_PAGESIZE);
const uint64_t result = pages * page_size;
# define UINT64_FORMAT "%" PRIu64
JLI_TraceLauncher("pages: " UINT64_FORMAT
" page_size: " UINT64_FORMAT
" physical memory: " UINT64_FORMAT " (%.3fGB)\n",
pages, page_size, result, result / (double) GB);
return result;
}