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6631166: CMS: better heuristics when combatting fragmentation

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Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.

Reviewed-by: jmasa
This commit is contained in:
Y. Srinivas Ramakrishna 2009-12-23 09:23:54 -08:00
parent 1383dc414b
commit 272a6d47bb
26 changed files with 1099 additions and 345 deletions
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45
hotspot/src/share/vm/runtime/arguments.cpp
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@ -948,6 +948,7 @@ static void no_shared_spaces() {
}
}
#ifndef KERNEL
// If the user has chosen ParallelGCThreads > 0, we set UseParNewGC
// if it's not explictly set or unset. If the user has chosen
// UseParNewGC and not explicitly set ParallelGCThreads we
@ -1177,8 +1178,7 @@ void Arguments::set_cms_and_parnew_gc_flags() {
// the value (either from the command line or ergonomics) of
// OldPLABSize. Following OldPLABSize is an ergonomics decision.
FLAG_SET_ERGO(uintx, CMSParPromoteBlocksToClaim, OldPLABSize);
}
else {
} else {
// OldPLABSize and CMSParPromoteBlocksToClaim are both set.
// CMSParPromoteBlocksToClaim is a collector-specific flag, so
// we'll let it to take precedence.
@ -1188,7 +1188,23 @@ void Arguments::set_cms_and_parnew_gc_flags() {
" CMSParPromoteBlocksToClaim will take precedence.\n");
}
}
if (!FLAG_IS_DEFAULT(ResizeOldPLAB) && !ResizeOldPLAB) {
// OldPLAB sizing manually turned off: Use a larger default setting,
// unless it was manually specified. This is because a too-low value
// will slow down scavenges.
if (FLAG_IS_DEFAULT(CMSParPromoteBlocksToClaim)) {
FLAG_SET_ERGO(uintx, CMSParPromoteBlocksToClaim, 50); // default value before 6631166
}
}
// Overwrite OldPLABSize which is the variable we will internally use everywhere.
FLAG_SET_ERGO(uintx, OldPLABSize, CMSParPromoteBlocksToClaim);
// If either of the static initialization defaults have changed, note this
// modification.
if (!FLAG_IS_DEFAULT(CMSParPromoteBlocksToClaim) || !FLAG_IS_DEFAULT(OldPLABWeight)) {
CFLS_LAB::modify_initialization(OldPLABSize, OldPLABWeight);
}
}
#endif // KERNEL
inline uintx max_heap_for_compressed_oops() {
LP64_ONLY(return oopDesc::OopEncodingHeapMax - MaxPermSize - os::vm_page_size());
@ -2370,22 +2386,25 @@ SOLARIS_ONLY(
"ExtendedDTraceProbes flag is only applicable on Solaris\n");
return JNI_EINVAL;
#endif // ndef SOLARIS
} else
#ifdef ASSERT
if (match_option(option, "-XX:+FullGCALot", &tail)) {
} else if (match_option(option, "-XX:+FullGCALot", &tail)) {
FLAG_SET_CMDLINE(bool, FullGCALot, true);
// disable scavenge before parallel mark-compact
FLAG_SET_CMDLINE(bool, ScavengeBeforeFullGC, false);
} else
#endif
if (match_option(option, "-XX:ParCMSPromoteBlocksToClaim=", &tail)) {
} else if (match_option(option, "-XX:CMSParPromoteBlocksToClaim=", &tail)) {
julong cms_blocks_to_claim = (julong)atol(tail);
FLAG_SET_CMDLINE(uintx, CMSParPromoteBlocksToClaim, cms_blocks_to_claim);
jio_fprintf(defaultStream::error_stream(),
"Please use -XX:CMSParPromoteBlocksToClaim in place of "
"Please use -XX:OldPLABSize in place of "
"-XX:CMSParPromoteBlocksToClaim in the future\n");
} else if (match_option(option, "-XX:ParCMSPromoteBlocksToClaim=", &tail)) {
julong cms_blocks_to_claim = (julong)atol(tail);
FLAG_SET_CMDLINE(uintx, CMSParPromoteBlocksToClaim, cms_blocks_to_claim);
jio_fprintf(defaultStream::error_stream(),
"Please use -XX:OldPLABSize in place of "
"-XX:ParCMSPromoteBlocksToClaim in the future\n");
} else
if (match_option(option, "-XX:ParallelGCOldGenAllocBufferSize=", &tail)) {
} else if (match_option(option, "-XX:ParallelGCOldGenAllocBufferSize=", &tail)) {
julong old_plab_size = 0;
ArgsRange errcode = parse_memory_size(tail, &old_plab_size, 1);
if (errcode != arg_in_range) {
@ -2398,8 +2417,7 @@ SOLARIS_ONLY(
jio_fprintf(defaultStream::error_stream(),
"Please use -XX:OldPLABSize in place of "
"-XX:ParallelGCOldGenAllocBufferSize in the future\n");
} else
if (match_option(option, "-XX:ParallelGCToSpaceAllocBufferSize=", &tail)) {
} else if (match_option(option, "-XX:ParallelGCToSpaceAllocBufferSize=", &tail)) {
julong young_plab_size = 0;
ArgsRange errcode = parse_memory_size(tail, &young_plab_size, 1);
if (errcode != arg_in_range) {
@ -2412,8 +2430,7 @@ SOLARIS_ONLY(
jio_fprintf(defaultStream::error_stream(),
"Please use -XX:YoungPLABSize in place of "
"-XX:ParallelGCToSpaceAllocBufferSize in the future\n");
} else
if (match_option(option, "-XX:", &tail)) { // -XX:xxxx
} else if (match_option(option, "-XX:", &tail)) { // -XX:xxxx
// Skip -XX:Flags= since that case has already been handled
if (strncmp(tail, "Flags=", strlen("Flags=")) != 0) {
if (!process_argument(tail, args->ignoreUnrecognized, origin)) {
@ -2727,6 +2744,7 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
return JNI_EINVAL;
}
#ifndef KERNEL
if (UseConcMarkSweepGC) {
// Set flags for CMS and ParNew. Check UseConcMarkSweep first
// to ensure that when both UseConcMarkSweepGC and UseParNewGC
@ -2744,6 +2762,7 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
set_g1_gc_flags();
}
}
#endif // KERNEL
#ifdef SERIALGC
assert(verify_serial_gc_flags(), "SerialGC unset");