author | tonyp |
Thu, 22 Jul 2010 10:27:41 -0400 | |
changeset 6248 | 2e661807cef0 |
parent 5926 | a36f90d986b6 |
child 6453 | 970dc585ab63 |
permissions | -rw-r--r-- |
1 | 1 |
/* |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
2 |
* Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
1 | 3 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 |
* |
|
5 |
* This code is free software; you can redistribute it and/or modify it |
|
6 |
* under the terms of the GNU General Public License version 2 only, as |
|
7 |
* published by the Free Software Foundation. |
|
8 |
* |
|
9 |
* This code is distributed in the hope that it will be useful, but WITHOUT |
|
10 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
11 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
12 |
* version 2 for more details (a copy is included in the LICENSE file that |
|
13 |
* accompanied this code). |
|
14 |
* |
|
15 |
* You should have received a copy of the GNU General Public License version |
|
16 |
* 2 along with this work; if not, write to the Free Software Foundation, |
|
17 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
18 |
* |
|
5547
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5533
diff
changeset
|
19 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5533
diff
changeset
|
20 |
* or visit www.oracle.com if you need additional information or have any |
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5533
diff
changeset
|
21 |
* questions. |
1 | 22 |
* |
23 |
*/ |
|
24 |
||
25 |
# include "incls/_precompiled.incl" |
|
26 |
# include "incls/_sweeper.cpp.incl" |
|
27 |
||
28 |
long NMethodSweeper::_traversals = 0; // No. of stack traversals performed |
|
5895
7127e98012e3
6956958: assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted() || is_optimized() || is_megam
never
parents:
5547
diff
changeset
|
29 |
nmethod* NMethodSweeper::_current = NULL; // Current nmethod |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
30 |
int NMethodSweeper::_seen = 0 ; // No. of nmethods we have currently processed in current pass of CodeCache |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
31 |
|
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
32 |
volatile int NMethodSweeper::_invocations = 0; // No. of invocations left until we are completed with this pass |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
33 |
volatile int NMethodSweeper::_sweep_started = 0; // Whether a sweep is in progress. |
1 | 34 |
|
35 |
jint NMethodSweeper::_locked_seen = 0; |
|
36 |
jint NMethodSweeper::_not_entrant_seen_on_stack = 0; |
|
37 |
bool NMethodSweeper::_rescan = false; |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
38 |
bool NMethodSweeper::_do_sweep = false; |
4750 | 39 |
bool NMethodSweeper::_was_full = false; |
40 |
jint NMethodSweeper::_advise_to_sweep = 0; |
|
41 |
jlong NMethodSweeper::_last_was_full = 0; |
|
42 |
uint NMethodSweeper::_highest_marked = 0; |
|
43 |
long NMethodSweeper::_was_full_traversal = 0; |
|
1 | 44 |
|
3908 | 45 |
class MarkActivationClosure: public CodeBlobClosure { |
46 |
public: |
|
47 |
virtual void do_code_blob(CodeBlob* cb) { |
|
48 |
// If we see an activation belonging to a non_entrant nmethod, we mark it. |
|
49 |
if (cb->is_nmethod() && ((nmethod*)cb)->is_not_entrant()) { |
|
50 |
((nmethod*)cb)->mark_as_seen_on_stack(); |
|
51 |
} |
|
52 |
} |
|
53 |
}; |
|
54 |
static MarkActivationClosure mark_activation_closure; |
|
55 |
||
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
56 |
void NMethodSweeper::scan_stacks() { |
1 | 57 |
assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); |
58 |
if (!MethodFlushing) return; |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
59 |
_do_sweep = true; |
1 | 60 |
|
61 |
// No need to synchronize access, since this is always executed at a |
|
62 |
// safepoint. If we aren't in the middle of scan and a rescan |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
63 |
// hasn't been requested then just return. If UseCodeCacheFlushing is on and |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
64 |
// code cache flushing is in progress, don't skip sweeping to help make progress |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
65 |
// clearing space in the code cache. |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
66 |
if ((_current == NULL && !_rescan) && !(UseCodeCacheFlushing && !CompileBroker::should_compile_new_jobs())) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
67 |
_do_sweep = false; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
68 |
return; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
69 |
} |
1 | 70 |
|
71 |
// Make sure CompiledIC_lock in unlocked, since we might update some |
|
72 |
// inline caches. If it is, we just bail-out and try later. |
|
73 |
if (CompiledIC_lock->is_locked() || Patching_lock->is_locked()) return; |
|
74 |
||
75 |
// Check for restart |
|
76 |
assert(CodeCache::find_blob_unsafe(_current) == _current, "Sweeper nmethod cached state invalid"); |
|
77 |
if (_current == NULL) { |
|
78 |
_seen = 0; |
|
79 |
_invocations = NmethodSweepFraction; |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
80 |
_current = CodeCache::first_nmethod(); |
1 | 81 |
_traversals += 1; |
82 |
if (PrintMethodFlushing) { |
|
83 |
tty->print_cr("### Sweep: stack traversal %d", _traversals); |
|
84 |
} |
|
3908 | 85 |
Threads::nmethods_do(&mark_activation_closure); |
1 | 86 |
|
87 |
// reset the flags since we started a scan from the beginning. |
|
88 |
_rescan = false; |
|
89 |
_locked_seen = 0; |
|
90 |
_not_entrant_seen_on_stack = 0; |
|
91 |
} |
|
92 |
||
4750 | 93 |
if (UseCodeCacheFlushing) { |
94 |
if (!CodeCache::needs_flushing()) { |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
95 |
// scan_stacks() runs during a safepoint, no race with setters |
4750 | 96 |
_advise_to_sweep = 0; |
97 |
} |
|
98 |
||
99 |
if (was_full()) { |
|
100 |
// There was some progress so attempt to restart the compiler |
|
101 |
jlong now = os::javaTimeMillis(); |
|
102 |
jlong max_interval = (jlong)MinCodeCacheFlushingInterval * (jlong)1000; |
|
103 |
jlong curr_interval = now - _last_was_full; |
|
104 |
if ((!CodeCache::needs_flushing()) && (curr_interval > max_interval)) { |
|
105 |
CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation); |
|
106 |
set_was_full(false); |
|
107 |
||
108 |
// Update the _last_was_full time so we can tell how fast the |
|
109 |
// code cache is filling up |
|
110 |
_last_was_full = os::javaTimeMillis(); |
|
111 |
||
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
112 |
log_sweep("restart_compiler"); |
4750 | 113 |
} |
114 |
} |
|
115 |
} |
|
1 | 116 |
} |
117 |
||
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
118 |
void NMethodSweeper::possibly_sweep() { |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
119 |
assert(JavaThread::current()->thread_state() == _thread_in_vm, "must run in vm mode"); |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
120 |
if ((!MethodFlushing) || (!_do_sweep)) return; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
121 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
122 |
if (_invocations > 0) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
123 |
// Only one thread at a time will sweep |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
124 |
jint old = Atomic::cmpxchg( 1, &_sweep_started, 0 ); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
125 |
if (old != 0) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
126 |
return; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
127 |
} |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
128 |
if (_invocations > 0) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
129 |
sweep_code_cache(); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
130 |
_invocations--; |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
131 |
} |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
132 |
_sweep_started = 0; |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
133 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
134 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
135 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
136 |
void NMethodSweeper::sweep_code_cache() { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
137 |
#ifdef ASSERT |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
138 |
jlong sweep_start; |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
139 |
if (PrintMethodFlushing) { |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
140 |
sweep_start = os::javaTimeMillis(); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
141 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
142 |
#endif |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
143 |
if (PrintMethodFlushing && Verbose) { |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
144 |
tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _invocations); |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
145 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
146 |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
147 |
// We want to visit all nmethods after NmethodSweepFraction |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
148 |
// invocations so divide the remaining number of nmethods by the |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
149 |
// remaining number of invocations. This is only an estimate since |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
150 |
// the number of nmethods changes during the sweep so the final |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
151 |
// stage must iterate until it there are no more nmethods. |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
152 |
int todo = (CodeCache::nof_nmethods() - _seen) / _invocations; |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
153 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
154 |
assert(!SafepointSynchronize::is_at_safepoint(), "should not be in safepoint when we get here"); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
155 |
assert(!CodeCache_lock->owned_by_self(), "just checking"); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
156 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
157 |
{ |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
158 |
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
159 |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
160 |
// The last invocation iterates until there are no more nmethods |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
161 |
for (int i = 0; (i < todo || _invocations == 1) && _current != NULL; i++) { |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
162 |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
163 |
// Since we will give up the CodeCache_lock, always skip ahead |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
164 |
// to the next nmethod. Other blobs can be deleted by other |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
165 |
// threads but nmethods are only reclaimed by the sweeper. |
5895
7127e98012e3
6956958: assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted() || is_optimized() || is_megam
never
parents:
5547
diff
changeset
|
166 |
nmethod* next = CodeCache::next_nmethod(_current); |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
167 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
168 |
// Now ready to process nmethod and give up CodeCache_lock |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
169 |
{ |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
170 |
MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
5895
7127e98012e3
6956958: assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted() || is_optimized() || is_megam
never
parents:
5547
diff
changeset
|
171 |
process_nmethod(_current); |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
172 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
173 |
_seen++; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
174 |
_current = next; |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
175 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
176 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
177 |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
178 |
assert(_invocations > 1 || _current == NULL, "must have scanned the whole cache"); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
179 |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
180 |
if (_current == NULL && !_rescan && (_locked_seen || _not_entrant_seen_on_stack)) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
181 |
// we've completed a scan without making progress but there were |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
182 |
// nmethods we were unable to process either because they were |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
183 |
// locked or were still on stack. We don't have to aggresively |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
184 |
// clean them up so just stop scanning. We could scan once more |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
185 |
// but that complicates the control logic and it's unlikely to |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
186 |
// matter much. |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
187 |
if (PrintMethodFlushing) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
188 |
tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep"); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
189 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
190 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
191 |
|
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
192 |
#ifdef ASSERT |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
193 |
if(PrintMethodFlushing) { |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
194 |
jlong sweep_end = os::javaTimeMillis(); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
195 |
tty->print_cr("### sweeper: sweep time(%d): " INT64_FORMAT, _invocations, sweep_end - sweep_start); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
196 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
197 |
#endif |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
198 |
|
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
199 |
if (_invocations == 1) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
200 |
log_sweep("finished"); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
201 |
} |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
202 |
} |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
203 |
|
1 | 204 |
|
205 |
void NMethodSweeper::process_nmethod(nmethod *nm) { |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
206 |
assert(!CodeCache_lock->owned_by_self(), "just checking"); |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
207 |
|
1 | 208 |
// Skip methods that are currently referenced by the VM |
209 |
if (nm->is_locked_by_vm()) { |
|
210 |
// But still remember to clean-up inline caches for alive nmethods |
|
211 |
if (nm->is_alive()) { |
|
212 |
// Clean-up all inline caches that points to zombie/non-reentrant methods |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
213 |
MutexLocker cl(CompiledIC_lock); |
1 | 214 |
nm->cleanup_inline_caches(); |
215 |
} else { |
|
216 |
_locked_seen++; |
|
217 |
} |
|
218 |
return; |
|
219 |
} |
|
220 |
||
221 |
if (nm->is_zombie()) { |
|
222 |
// If it is first time, we see nmethod then we mark it. Otherwise, |
|
223 |
// we reclame it. When we have seen a zombie method twice, we know that |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
224 |
// there are no inline caches that refer to it. |
1 | 225 |
if (nm->is_marked_for_reclamation()) { |
226 |
assert(!nm->is_locked_by_vm(), "must not flush locked nmethods"); |
|
3696 | 227 |
if (PrintMethodFlushing && Verbose) { |
4750 | 228 |
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm); |
3696 | 229 |
} |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
230 |
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
1 | 231 |
nm->flush(); |
232 |
} else { |
|
3696 | 233 |
if (PrintMethodFlushing && Verbose) { |
4750 | 234 |
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm); |
3696 | 235 |
} |
1 | 236 |
nm->mark_for_reclamation(); |
237 |
_rescan = true; |
|
238 |
} |
|
239 |
} else if (nm->is_not_entrant()) { |
|
240 |
// If there is no current activations of this method on the |
|
241 |
// stack we can safely convert it to a zombie method |
|
242 |
if (nm->can_not_entrant_be_converted()) { |
|
3696 | 243 |
if (PrintMethodFlushing && Verbose) { |
4750 | 244 |
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm); |
3696 | 245 |
} |
1 | 246 |
nm->make_zombie(); |
247 |
_rescan = true; |
|
248 |
} else { |
|
249 |
// Still alive, clean up its inline caches |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
250 |
MutexLocker cl(CompiledIC_lock); |
1 | 251 |
nm->cleanup_inline_caches(); |
252 |
// we coudn't transition this nmethod so don't immediately |
|
253 |
// request a rescan. If this method stays on the stack for a |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
254 |
// long time we don't want to keep rescanning the code cache. |
1 | 255 |
_not_entrant_seen_on_stack++; |
256 |
} |
|
257 |
} else if (nm->is_unloaded()) { |
|
258 |
// Unloaded code, just make it a zombie |
|
3696 | 259 |
if (PrintMethodFlushing && Verbose) |
4750 | 260 |
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (unloaded) being made zombie", nm->compile_id(), nm); |
3696 | 261 |
if (nm->is_osr_method()) { |
1 | 262 |
// No inline caches will ever point to osr methods, so we can just remove it |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
263 |
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
1 | 264 |
nm->flush(); |
265 |
} else { |
|
266 |
nm->make_zombie(); |
|
267 |
_rescan = true; |
|
268 |
} |
|
269 |
} else { |
|
270 |
assert(nm->is_alive(), "should be alive"); |
|
4750 | 271 |
|
272 |
if (UseCodeCacheFlushing) { |
|
273 |
if ((nm->method()->code() != nm) && !(nm->is_locked_by_vm()) && !(nm->is_osr_method()) && |
|
274 |
(_traversals > _was_full_traversal+2) && (((uint)nm->compile_id()) < _highest_marked) && |
|
275 |
CodeCache::needs_flushing()) { |
|
276 |
// This method has not been called since the forced cleanup happened |
|
277 |
nm->make_not_entrant(); |
|
278 |
} |
|
279 |
} |
|
280 |
||
1 | 281 |
// Clean-up all inline caches that points to zombie/non-reentrant methods |
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
282 |
MutexLocker cl(CompiledIC_lock); |
1 | 283 |
nm->cleanup_inline_caches(); |
284 |
} |
|
285 |
} |
|
4750 | 286 |
|
287 |
// Code cache unloading: when compilers notice the code cache is getting full, |
|
288 |
// they will call a vm op that comes here. This code attempts to speculatively |
|
289 |
// unload the oldest half of the nmethods (based on the compile job id) by |
|
290 |
// saving the old code in a list in the CodeCache. Then |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
291 |
// execution resumes. If a method so marked is not called by the second sweeper |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
292 |
// stack traversal after the current one, the nmethod will be marked non-entrant and |
4750 | 293 |
// got rid of by normal sweeping. If the method is called, the methodOop's |
294 |
// _code field is restored and the methodOop/nmethod |
|
295 |
// go back to their normal state. |
|
296 |
void NMethodSweeper::handle_full_code_cache(bool is_full) { |
|
297 |
// Only the first one to notice can advise us to start early cleaning |
|
298 |
if (!is_full){ |
|
299 |
jint old = Atomic::cmpxchg( 1, &_advise_to_sweep, 0 ); |
|
300 |
if (old != 0) { |
|
301 |
return; |
|
302 |
} |
|
303 |
} |
|
304 |
||
305 |
if (is_full) { |
|
306 |
// Since code cache is full, immediately stop new compiles |
|
307 |
bool did_set = CompileBroker::set_should_compile_new_jobs(CompileBroker::stop_compilation); |
|
308 |
if (!did_set) { |
|
309 |
// only the first to notice can start the cleaning, |
|
310 |
// others will go back and block |
|
311 |
return; |
|
312 |
} |
|
313 |
set_was_full(true); |
|
314 |
||
315 |
// If we run out within MinCodeCacheFlushingInterval of the last unload time, give up |
|
316 |
jlong now = os::javaTimeMillis(); |
|
317 |
jlong max_interval = (jlong)MinCodeCacheFlushingInterval * (jlong)1000; |
|
318 |
jlong curr_interval = now - _last_was_full; |
|
319 |
if (curr_interval < max_interval) { |
|
320 |
_rescan = true; |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
321 |
log_sweep("disable_compiler", "flushing_interval='" UINT64_FORMAT "'", |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
322 |
curr_interval/1000); |
4750 | 323 |
return; |
324 |
} |
|
325 |
} |
|
326 |
||
327 |
VM_HandleFullCodeCache op(is_full); |
|
328 |
VMThread::execute(&op); |
|
329 |
||
330 |
// rescan again as soon as possible |
|
331 |
_rescan = true; |
|
332 |
} |
|
333 |
||
334 |
void NMethodSweeper::speculative_disconnect_nmethods(bool is_full) { |
|
335 |
// If there was a race in detecting full code cache, only run |
|
336 |
// one vm op for it or keep the compiler shut off |
|
337 |
||
338 |
debug_only(jlong start = os::javaTimeMillis();) |
|
339 |
||
340 |
if ((!was_full()) && (is_full)) { |
|
341 |
if (!CodeCache::needs_flushing()) { |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
342 |
log_sweep("restart_compiler"); |
4750 | 343 |
CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation); |
344 |
return; |
|
345 |
} |
|
346 |
} |
|
347 |
||
348 |
// Traverse the code cache trying to dump the oldest nmethods |
|
349 |
uint curr_max_comp_id = CompileBroker::get_compilation_id(); |
|
350 |
uint flush_target = ((curr_max_comp_id - _highest_marked) >> 1) + _highest_marked; |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
351 |
log_sweep("start_cleaning"); |
4750 | 352 |
|
353 |
nmethod* nm = CodeCache::alive_nmethod(CodeCache::first()); |
|
354 |
jint disconnected = 0; |
|
355 |
jint made_not_entrant = 0; |
|
356 |
while ((nm != NULL)){ |
|
357 |
uint curr_comp_id = nm->compile_id(); |
|
358 |
||
359 |
// OSR methods cannot be flushed like this. Also, don't flush native methods |
|
360 |
// since they are part of the JDK in most cases |
|
361 |
if (nm->is_in_use() && (!nm->is_osr_method()) && (!nm->is_locked_by_vm()) && |
|
362 |
(!nm->is_native_method()) && ((curr_comp_id < flush_target))) { |
|
363 |
||
364 |
if ((nm->method()->code() == nm)) { |
|
365 |
// This method has not been previously considered for |
|
366 |
// unloading or it was restored already |
|
367 |
CodeCache::speculatively_disconnect(nm); |
|
368 |
disconnected++; |
|
369 |
} else if (nm->is_speculatively_disconnected()) { |
|
370 |
// This method was previously considered for preemptive unloading and was not called since then |
|
371 |
nm->method()->invocation_counter()->decay(); |
|
372 |
nm->method()->backedge_counter()->decay(); |
|
373 |
nm->make_not_entrant(); |
|
374 |
made_not_entrant++; |
|
375 |
} |
|
376 |
||
377 |
if (curr_comp_id > _highest_marked) { |
|
378 |
_highest_marked = curr_comp_id; |
|
379 |
} |
|
380 |
} |
|
381 |
nm = CodeCache::alive_nmethod(CodeCache::next(nm)); |
|
382 |
} |
|
383 |
||
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
384 |
log_sweep("stop_cleaning", |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
385 |
"disconnected='" UINT32_FORMAT "' made_not_entrant='" UINT32_FORMAT "'", |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
386 |
disconnected, made_not_entrant); |
4750 | 387 |
|
5533
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
388 |
// Shut off compiler. Sweeper will start over with a new stack scan and |
e8d9ff82ec62
6950075: nmethod sweeper should operate concurrently
never
parents:
4750
diff
changeset
|
389 |
// traversal cycle and turn it back on if it clears enough space. |
4750 | 390 |
if (was_full()) { |
391 |
_last_was_full = os::javaTimeMillis(); |
|
392 |
CompileBroker::set_should_compile_new_jobs(CompileBroker::stop_compilation); |
|
393 |
} |
|
394 |
||
395 |
// After two more traversals the sweeper will get rid of unrestored nmethods |
|
396 |
_was_full_traversal = _traversals; |
|
397 |
#ifdef ASSERT |
|
398 |
jlong end = os::javaTimeMillis(); |
|
399 |
if(PrintMethodFlushing && Verbose) { |
|
400 |
tty->print_cr("### sweeper: unload time: " INT64_FORMAT, end-start); |
|
401 |
} |
|
402 |
#endif |
|
403 |
} |
|
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
404 |
|
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
405 |
|
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
406 |
// Print out some state information about the current sweep and the |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
407 |
// state of the code cache if it's requested. |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
408 |
void NMethodSweeper::log_sweep(const char* msg, const char* format, ...) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
409 |
if (PrintMethodFlushing) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
410 |
ttyLocker ttyl; |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
411 |
tty->print("### sweeper: %s ", msg); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
412 |
if (format != NULL) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
413 |
va_list ap; |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
414 |
va_start(ap, format); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
415 |
tty->vprint(format, ap); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
416 |
va_end(ap); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
417 |
} |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
418 |
tty->print_cr(" total_blobs='" UINT32_FORMAT "' nmethods='" UINT32_FORMAT "'" |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
419 |
" adapters='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
420 |
CodeCache::nof_blobs(), CodeCache::nof_nmethods(), CodeCache::nof_adapters(), CodeCache::unallocated_capacity()); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
421 |
} |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
422 |
|
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
423 |
if (LogCompilation && (xtty != NULL)) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
424 |
ttyLocker ttyl; |
5926 | 425 |
xtty->begin_elem("sweeper state='%s' traversals='" INTX_FORMAT "' ", msg, (intx)traversal_count()); |
5924
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
426 |
if (format != NULL) { |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
427 |
va_list ap; |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
428 |
va_start(ap, format); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
429 |
xtty->vprint(format, ap); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
430 |
va_end(ap); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
431 |
} |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
432 |
xtty->print(" total_blobs='" UINT32_FORMAT "' nmethods='" UINT32_FORMAT "'" |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
433 |
" adapters='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
434 |
CodeCache::nof_blobs(), CodeCache::nof_nmethods(), CodeCache::nof_adapters(), CodeCache::unallocated_capacity()); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
435 |
xtty->stamp(); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
436 |
xtty->end_elem(); |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
437 |
} |
dc9d04930c82
6965184: possible races in make_not_entrant_or_zombie
never
parents:
5895
diff
changeset
|
438 |
} |