Revision 46daff13 cpus.c
| b/cpus.c | ||
|---|---|---|
| 636 | 636 |
#else /* CONFIG_IOTHREAD */ |
| 637 | 637 |
|
| 638 | 638 |
QemuMutex qemu_global_mutex; |
| 639 |
static QemuMutex qemu_fair_mutex; |
|
| 639 |
static QemuCond qemu_io_proceeded_cond; |
|
| 640 |
static bool iothread_requesting_mutex; |
|
| 640 | 641 |
|
| 641 | 642 |
static QemuThread io_thread; |
| 642 | 643 |
|
| ... | ... | |
| 672 | 673 |
qemu_cond_init(&qemu_system_cond); |
| 673 | 674 |
qemu_cond_init(&qemu_pause_cond); |
| 674 | 675 |
qemu_cond_init(&qemu_work_cond); |
| 675 |
qemu_mutex_init(&qemu_fair_mutex);
|
|
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qemu_cond_init(&qemu_io_proceeded_cond);
|
|
| 676 | 677 |
qemu_mutex_init(&qemu_global_mutex); |
| 677 | 678 |
qemu_mutex_lock(&qemu_global_mutex); |
| 678 | 679 |
|
| ... | ... | |
| 755 | 756 |
qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex); |
| 756 | 757 |
} |
| 757 | 758 |
|
| 758 |
qemu_mutex_unlock(&qemu_global_mutex); |
|
| 759 |
|
|
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/* |
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* Users of qemu_global_mutex can be starved, having no chance |
|
| 762 |
* to acquire it since this path will get to it first. |
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| 763 |
* So use another lock to provide fairness. |
|
| 764 |
*/ |
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qemu_mutex_lock(&qemu_fair_mutex); |
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qemu_mutex_unlock(&qemu_fair_mutex); |
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| 767 |
|
|
| 768 |
qemu_mutex_lock(&qemu_global_mutex); |
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| 759 |
while (iothread_requesting_mutex) {
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|
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qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex); |
|
| 761 |
} |
|
| 769 | 762 |
|
| 770 | 763 |
for (env = first_cpu; env != NULL; env = env->next_cpu) {
|
| 771 | 764 |
qemu_wait_io_event_common(env); |
| ... | ... | |
| 908 | 901 |
if (kvm_enabled()) {
|
| 909 | 902 |
qemu_mutex_lock(&qemu_global_mutex); |
| 910 | 903 |
} else {
|
| 911 |
qemu_mutex_lock(&qemu_fair_mutex);
|
|
| 904 |
iothread_requesting_mutex = true;
|
|
| 912 | 905 |
if (qemu_mutex_trylock(&qemu_global_mutex)) {
|
| 913 | 906 |
qemu_cpu_kick_thread(first_cpu); |
| 914 | 907 |
qemu_mutex_lock(&qemu_global_mutex); |
| 915 | 908 |
} |
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qemu_mutex_unlock(&qemu_fair_mutex); |
|
| 909 |
iothread_requesting_mutex = false; |
|
| 910 |
qemu_cond_broadcast(&qemu_io_proceeded_cond); |
|
| 917 | 911 |
} |
| 918 | 912 |
} |
| 919 | 913 |
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