/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "runtime/advancedThresholdPolicy.hpp"
#include "runtime/simpleThresholdPolicy.inline.hpp"
#ifdef TIERED
// Print an event.
}
// Turn on ergonomic compiler count selection
}
if (CICompilerCountPerCPU) {
// Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
}
// Some inlining tuning
#ifdef X86
if (FLAG_IS_DEFAULT(InlineSmallCode)) {
}
#endif
#ifdef SPARC
if (FLAG_IS_DEFAULT(InlineSmallCode)) {
}
#endif
}
// update_rate() is called from select_task() while holding a compile queue lock.
if (is_old(m)) {
// We don't remove old methods from the queue,
// so we can just zero the rate.
m->set_rate(0);
return;
}
// We don't update the rate if we've just came out of a safepoint.
// delta_s is the time since last safepoint in milliseconds.
jlong delta_t = t - (m->prev_time() != 0 ? m->prev_time() : start_time()); // milliseconds since the last measurement
// How many events were there since the last time?
// We should be running for at least 1ms.
if (delta_s >= TieredRateUpdateMinTime) {
// And we must've taken the previous point at least 1ms before.
m->set_prev_time(t);
} else
// If nothing happened for 25ms, zero the rate. Don't modify prev values.
m->set_rate(0);
}
}
}
// Check if this method has been stale from a given number of milliseconds.
// See select_task().
// Return true if there were no events.
return delta_e == 0;
}
return false;
}
// We don't remove old methods from the compile queue even if they have
// very low activity. See select_task().
}
}
// Apply heuristics and return true if x should be compiled before y
if (x->highest_comp_level() > y->highest_comp_level()) {
// recompilation after deopt
return true;
} else
if (x->highest_comp_level() == y->highest_comp_level()) {
return true;
}
}
return false;
}
// Is method profiled enough?
int i = mdo->invocation_count_delta();
int b = mdo->backedge_count_delta();
}
return false;
}
// Called with the queue locked and with at least one element
// Iterate through the queue and find a method with a maximum rate.
update_rate(t, method());
max_method = method;
} else {
// If a method has been stale for some time, remove it from the queue.
if (PrintTieredEvents) {
}
continue;
}
// Select a method with a higher rate
max_method = method;
}
}
}
&& is_method_profiled(max_method())) {
if (PrintTieredEvents) {
print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
}
}
return max_task;
}
return k;
}
// Call and loop predicates determine whether a transition to a higher
// compilation level should be performed (pointers to predicate functions
// are passed to common()).
// Tier?LoadFeedback is basically a coefficient that determines of
// how many methods per compiler thread can be in the queue before
// the threshold values double.
switch(cur_level) {
case CompLevel_none:
case CompLevel_limited_profile: {
return loop_predicate_helper<CompLevel_none>(i, b, k);
}
case CompLevel_full_profile: {
return loop_predicate_helper<CompLevel_full_profile>(i, b, k);
}
default:
return true;
}
}
switch(cur_level) {
case CompLevel_none:
case CompLevel_limited_profile: {
return call_predicate_helper<CompLevel_none>(i, b, k);
}
case CompLevel_full_profile: {
return call_predicate_helper<CompLevel_full_profile>(i, b, k);
}
default:
return true;
}
}
// If a method is old enough and is still in the interpreter we would want to
// start profiling without waiting for the compiled method to arrive.
// We also take the load on compilers into the account.
if (cur_level == CompLevel_none &&
int i = method->invocation_count();
int b = method->backedge_count();
double k = Tier0ProfilingStartPercentage / 100.0;
return call_predicate_helper<CompLevel_none>(i, b, k) || loop_predicate_helper<CompLevel_none>(i, b, k);
}
return false;
}
// Inlining control: if we're compiling a profiled method with C1 and the callee
// is known to have OSRed in a C2 version, don't inline it.
if (comp_level == CompLevel_full_profile ||
}
return false;
}
// Create MDO if necessary.
}
}
/*
* Method states:
* 0 - interpreter (CompLevel_none)
* 1 - pure C1 (CompLevel_simple)
* 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
* 3 - C1 with full profiling (CompLevel_full_profile)
* 4 - C2 (CompLevel_full_optimization)
*
* Common state transition patterns:
* a. 0 -> 3 -> 4.
* The most common path. But note that even in this straightforward case
* profiling can start at level 0 and finish at level 3.
*
* b. 0 -> 2 -> 3 -> 4.
* This case occures when the load on C2 is deemed too high. So, instead of transitioning
* into state 3 directly and over-profiling while a method is in the C2 queue we transition to
* level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
*
* c. 0 -> (3->2) -> 4.
* In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
* to enable the profiling to fully occur at level 0. In this case we change the compilation level
* of the method to 2, because it'll allow it to run much faster without full profiling while c2
* is compiling.
*
* d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
* After a method was once compiled with C1 it can be identified as trivial and be compiled to
* level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
*
* e. 0 -> 4.
* This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
* or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
* the compiled version already exists).
*
* Note that since state 0 can be reached from any other state via deoptimization different loops
* are possible.
*
*/
// Common transition function. Given a predicate determines if a method should transition to another level.
CompLevel AdvancedThresholdPolicy::common(Predicate p, methodOop method, CompLevel cur_level, bool disable_feedback) {
int i = method->invocation_count();
int b = method->backedge_count();
if (is_trivial(method)) {
} else {
switch(cur_level) {
case CompLevel_none:
// If we were at full profile level, would we switch to full opt?
} else if ((this->*p)(i, b, cur_level)) {
// C1-generated fully profiled code is about 30% slower than the limited profile
// code that has only invocation and backedge counters. The observation is that
// if C2 queue is large enough we can spend too much time in the fully profiled code
// while waiting for C2 to pick the method from the queue. To alleviate this problem
// we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
// we choose to compile a limited profiled version and then recompile with full profiling
// when the load on C2 goes down.
} else {
}
}
break;
if (is_method_profiled(method)) {
// Special case: we got here because this method was fully profiled in the interpreter.
} else {
if (mdo->would_profile()) {
(this->*p)(i, b, cur_level))) {
}
} else {
}
}
}
break;
case CompLevel_full_profile:
{
if (mdo->would_profile()) {
}
} else {
}
}
}
break;
}
}
}
// Determine if a method should be compiled with a normal entry point at a different level.
// If OSR method level is greater than the regular method level, the levels should be
// equalized by raising the regular method level in order to avoid OSRs during each
// invocation of the method.
}
} else {
}
return next_level;
}
// Determine if we should do an OSR compilation of a given method.
if (cur_level == CompLevel_none) {
// If there is a live OSR method that means that we deopted to the interpreter
// for the transition.
if (osr_level > CompLevel_none) {
return osr_level;
}
}
return next_level;
}
// Update the rate and submit compile
void AdvancedThresholdPolicy::submit_compile(methodHandle mh, int bci, CompLevel level, JavaThread* thread) {
}
// Handle the invocation event.
}
if (next_level != level) {
}
}
}
// Handle the back branch event. Notice that we can compile the method
// with a regular entry from here.
}
// Check if MDO should be created for the inlined method
}
if (is_compilation_enabled()) {
// At the very least compile the OSR version
}
// Use loop event as an opportunity to also check if there's been
// enough calls.
if (max_osr_level == CompLevel_full_optimization) {
// The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
bool make_not_entrant = false;
if (nm->is_osr_method()) {
// This is an osr method, just make it not entrant and recompile later if needed
make_not_entrant = true;
} else {
if (next_level != CompLevel_full_optimization) {
// next_level is not full opt, so we need to recompile the
// enclosing method without the inlinee
make_not_entrant = true;
}
}
if (make_not_entrant) {
if (PrintTieredEvents) {
}
nm->make_not_entrant();
}
}
// Fix up next_level if necessary to avoid deopts
}
if (cur_level != next_level) {
}
}
} else {
}
}
}
}
#endif // TIERED