jdk8-mips64-public/hotspot: src/cpu/sparc/vm/vm_version

src/cpu/sparc/vm/vm_version_sparc.cpp@3bfae429e2cf (annotated)

src/cpu/sparc/vm/vm_version_sparc.cpp

Mon, 03 May 2010 10:24:51 -0700

author: ysr
date: Mon, 03 May 2010 10:24:51 -0700
changeset 1873: 3bfae429e2cf
parent 1802: 9e321dcfa5b7
child 1907: c18cbe5936b8
child 1930: 3657cb01ffc5
permissions: -rw-r--r--

6948537: CMS: BOT walkers observe out-of-thin-air zeros on sun4v sparc/CMT
Summary: On sun4v/CMT avoid use of memset() in BOT updates so as to prevent concurrent BOT readers from seeing the phantom zeros arising from memset()'s use of BIS.
Reviewed-by: jmasa, johnc, minqi, poonam, tonyp

 /*
  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 # include "incls/_precompiled.incl"
 # include "incls/_vm_version_sparc.cpp.incl"
 int VM_Version::_features = VM_Version::unknown_m;
 const char* VM_Version::_features_str = "";
 bool VM_Version::is_niagara1_plus() {
   // This is a placeholder until the real test is determined.
   return is_niagara1() &&
     (os::processor_count() > maximum_niagara1_processor_count());
 }
 void VM_Version::initialize() {
   _features = determine_features();
   PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
   PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
   PrefetchFieldsAhead         = prefetch_fields_ahead();
   // Allocation prefetch settings
   intx cache_line_size = L1_data_cache_line_size();
   if( cache_line_size > AllocatePrefetchStepSize )
     AllocatePrefetchStepSize = cache_line_size;
   if( FLAG_IS_DEFAULT(AllocatePrefetchLines) )
     AllocatePrefetchLines = 3; // Optimistic value
   assert( AllocatePrefetchLines > 0, "invalid value");
   if( AllocatePrefetchLines < 1 ) // set valid value in product VM
     AllocatePrefetchLines = 1; // Conservative value
   AllocatePrefetchDistance = allocate_prefetch_distance();
   AllocatePrefetchStyle    = allocate_prefetch_style();
   assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");
   UseSSE = 0; // Only on x86 and x64
   _supports_cx8               = has_v9();
   if (is_niagara1()) {
     // Indirect branch is the same cost as direct
     if (FLAG_IS_DEFAULT(UseInlineCaches)) {
       FLAG_SET_DEFAULT(UseInlineCaches, false);
     }
 #ifdef _LP64
     // Single issue niagara1 is slower for CompressedOops
     // but niagaras after that it's fine.
     if (!is_niagara1_plus()) {
       if (FLAG_IS_DEFAULT(UseCompressedOops)) {
         FLAG_SET_ERGO(bool, UseCompressedOops, false);
       }
     }
     // 32-bit oops don't make sense for the 64-bit VM on sparc
     // since the 32-bit VM has the same registers and smaller objects.
     Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 #endif // _LP64
 #ifdef COMPILER2
     // Indirect branch is the same cost as direct
     if (FLAG_IS_DEFAULT(UseJumpTables)) {
       FLAG_SET_DEFAULT(UseJumpTables, true);
     }
     // Single-issue, so entry and loop tops are
     // aligned on a single instruction boundary
     if (FLAG_IS_DEFAULT(InteriorEntryAlignment)) {
       FLAG_SET_DEFAULT(InteriorEntryAlignment, 4);
     }
     if (is_niagara1_plus()) {
       if (AllocatePrefetchStyle > 0 && FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
         // Use BIS instruction for allocation prefetch.
         FLAG_SET_DEFAULT(AllocatePrefetchStyle, 3);
         if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
           // Use smaller prefetch distance on N2 with BIS
           FLAG_SET_DEFAULT(AllocatePrefetchDistance, 64);
         }
       }
       if (AllocatePrefetchStyle != 3 && FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
         // Use different prefetch distance without BIS
         FLAG_SET_DEFAULT(AllocatePrefetchDistance, 256);
       }
     }
 #endif
     if (FLAG_IS_DEFAULT(OptoLoopAlignment)) {
       FLAG_SET_DEFAULT(OptoLoopAlignment, 4);
     }
     // When using CMS, we cannot use memset() in BOT updates because
     // the sun4v/CMT version in libc_psr uses BIS which exposes
     // "phantom zeros" to concurrent readers. See 6948537.
     if (FLAG_IS_DEFAULT(UseMemSetInBOT) && UseConcMarkSweepGC) {
       FLAG_SET_DEFAULT(UseMemSetInBOT, false);
     }
   }
   // Use hardware population count instruction if available.
   if (has_hardware_popc()) {
     if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
       FLAG_SET_DEFAULT(UsePopCountInstruction, true);
     }
   }
   char buf[512];
   jio_snprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s%s%s%s%s",
                (has_v8() ? ", has_v8" : ""),
                (has_v9() ? ", has_v9" : ""),
                (has_hardware_popc() ? ", popc" : ""),
                (has_vis1() ? ", has_vis1" : ""),
                (has_vis2() ? ", has_vis2" : ""),
                (is_ultra3() ? ", is_ultra3" : ""),
                (is_sun4v() ? ", is_sun4v" : ""),
                (is_niagara1() ? ", is_niagara1" : ""),
                (is_niagara1_plus() ? ", is_niagara1_plus" : ""),
                (!has_hardware_mul32() ? ", no-mul32" : ""),
                (!has_hardware_div32() ? ", no-div32" : ""),
                (!has_hardware_fsmuld() ? ", no-fsmuld" : ""));
   // buf is started with ", " or is empty
   _features_str = strdup(strlen(buf) > 2 ? buf + 2 : buf);
 #ifndef PRODUCT
   if (PrintMiscellaneous && Verbose) {
     tty->print("Allocation: ");
     if (AllocatePrefetchStyle <= 0) {
       tty->print_cr("no prefetching");
     } else {
       if (AllocatePrefetchLines > 1) {
         tty->print_cr("PREFETCH %d, %d lines of size %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
       } else {
         tty->print_cr("PREFETCH %d, one line", AllocatePrefetchDistance);
       }
     }
     if (PrefetchCopyIntervalInBytes > 0) {
       tty->print_cr("PrefetchCopyIntervalInBytes %d", PrefetchCopyIntervalInBytes);
     }
     if (PrefetchScanIntervalInBytes > 0) {
       tty->print_cr("PrefetchScanIntervalInBytes %d", PrefetchScanIntervalInBytes);
     }
     if (PrefetchFieldsAhead > 0) {
       tty->print_cr("PrefetchFieldsAhead %d", PrefetchFieldsAhead);
     }
   }
 #endif // PRODUCT
 }
 void VM_Version::print_features() {
   tty->print_cr("Version:%s", cpu_features());
 }
 int VM_Version::determine_features() {
   if (UseV8InstrsOnly) {
     NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-V8");)
     return generic_v8_m;
   }
   int features = platform_features(unknown_m); // platform_features() is os_arch specific
   if (features == unknown_m) {
     features = generic_v9_m;
     warning("Cannot recognize SPARC version. Default to V9");
   }
   if (UseNiagaraInstrs) {
     if (is_niagara1(features)) {
       // Happy to accomodate...
     } else {
       NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Niagara");)
       features = niagara1_m;
     }
   } else {
     if (is_niagara1(features) && !FLAG_IS_DEFAULT(UseNiagaraInstrs)) {
       NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Not-Niagara");)
       features &= ~niagara1_unique_m;
     } else {
       // Happy to accomodate...
     }
   }
   return features;
 }
 static int saved_features = 0;
 void VM_Version::allow_all() {
   saved_features = _features;
   _features      = all_features_m;
 }
 void VM_Version::revert() {
   _features = saved_features;
 }
 unsigned int VM_Version::calc_parallel_worker_threads() {
   unsigned int result;
   if (is_niagara1_plus()) {
     result = nof_parallel_worker_threads(5, 16, 8);
   } else {
     result = nof_parallel_worker_threads(5, 8, 8);
   }
   return result;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/cpu/sparc/vm/vm_version_sparc.cpp@3bfae429e2cf (annotated)

src/cpu/sparc/vm/vm_version_sparc.cpp