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[Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap
From: |
Liu Ping Fan |
Subject: |
[Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap |
Date: |
Tue, 11 Sep 2012 15:51:51 +0800 |
From: Liu Ping Fan <address@hidden>
The func call chain can suffer from recursively hold
qemu_mutex_lock_iothread. We introduce lockmap to record the
lock depth.
Signed-off-by: Liu Ping Fan <address@hidden>
---
cpus.c | 18 ++++++++++++++++++
qemu-thread-posix.c | 23 +++++++++++++++++++++++
qemu-thread-posix.h | 5 +++++
qemu-thread.h | 3 +++
4 files changed, 49 insertions(+), 0 deletions(-)
diff --git a/cpus.c b/cpus.c
index 4cd7f85..09f6670 100644
--- a/cpus.c
+++ b/cpus.c
@@ -736,6 +736,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
int r;
pthread_setspecific(qemu_thread_key, cpu->thread);
+ cpu->thread->lockmap.biglock = 0;
+ qemu_big_lockmap_inc();
qemu_mutex_lock(&qemu_global_mutex);
qemu_thread_get_self(cpu->thread);
env->thread_id = qemu_get_thread_id();
@@ -905,6 +907,14 @@ int qemu_cpu_is_self(void *_env)
void qemu_mutex_lock_iothread(void)
{
+ unsigned int map;
+
+ if (!qemu_thread_is_self(&io_thread)) {
+ map = qemu_big_lockmap_inc();
+ if (map > 1) {
+ return;
+ }
+ }
if (!tcg_enabled()) {
qemu_mutex_lock(&qemu_global_mutex);
} else {
@@ -920,6 +930,14 @@ void qemu_mutex_lock_iothread(void)
void qemu_mutex_unlock_iothread(void)
{
+ unsigned int map;
+
+ if (!qemu_thread_is_self(&io_thread)) {
+ map = qemu_big_lockmap_dec();
+ if (map != 0) {
+ return;
+ }
+ }
qemu_mutex_unlock(&qemu_global_mutex);
}
diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c
index f448fcb..1e07dc2 100644
--- a/qemu-thread-posix.c
+++ b/qemu-thread-posix.c
@@ -17,6 +17,7 @@
#include <signal.h>
#include <stdint.h>
#include <string.h>
+#include <glib.h>
#include "qemu-thread.h"
pthread_key_t qemu_thread_key;
@@ -158,6 +159,28 @@ void qemu_thread_key_create(void)
pthread_key_create(&qemu_thread_key, NULL);
}
+int16_t qemu_big_lockmap_inc(void)
+{
+ QemuThread *t = pthread_getspecific(qemu_thread_key);
+
+ return ++t->lockmap.biglock;
+}
+
+int16_t qemu_big_lockmap_dec(void)
+{
+ QemuThread *t = pthread_getspecific(qemu_thread_key);
+ g_assert(t->lockmap.biglock > 0);
+
+ return --t->lockmap.biglock;
+}
+
+int16_t qemu_big_lockmap_get(void)
+{
+ QemuThread *t = pthread_getspecific(qemu_thread_key);
+
+ return t->lockmap.biglock;
+}
+
bool qemu_thread_is_self(QemuThread *thread)
{
return pthread_equal(pthread_self(), thread->thread);
diff --git a/qemu-thread-posix.h b/qemu-thread-posix.h
index 2607b1c..8f9506b 100644
--- a/qemu-thread-posix.h
+++ b/qemu-thread-posix.h
@@ -10,8 +10,13 @@ struct QemuCond {
pthread_cond_t cond;
};
+typedef struct Lockmap {
+ int16_t biglock;
+} Lockmap;
+
struct QemuThread {
pthread_t thread;
+ Lockmap lockmap;
};
extern pthread_key_t qemu_thread_key;
diff --git a/qemu-thread.h b/qemu-thread.h
index 4a6427d..529850b 100644
--- a/qemu-thread.h
+++ b/qemu-thread.h
@@ -47,4 +47,7 @@ bool qemu_thread_is_self(QemuThread *thread);
void qemu_thread_exit(void *retval);
void qemu_thread_key_create(void);
+int16_t qemu_big_lockmap_inc(void);
+int16_t qemu_big_lockmap_dec(void);
+int16_t qemu_big_lockmap_get(void);
#endif
--
1.7.4.4
- [Qemu-devel] [PATCH V3 01/11] atomic: introduce atomic operations, (continued)
- [Qemu-devel] [PATCH V3 01/11] atomic: introduce atomic operations, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 02/11] qom: apply atomic on object's refcount, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 03/11] hotplug: introduce qdev_unplug_complete() to remove device from views, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 04/11] pci: remove pci device from mem view when unplug, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 05/11] memory: introduce ref, unref interface for MemoryRegionOps, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 07/11] memory: implement e1000's MemoryRegionOps ref/unref, Liu Ping Fan, 2012/09/11
- [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap,
Liu Ping Fan <=
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Avi Kivity, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, liu ping fan, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Avi Kivity, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Jan Kiszka, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Avi Kivity, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Jan Kiszka, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Avi Kivity, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Jan Kiszka, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Avi Kivity, 2012/09/11
- Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap, Jan Kiszka, 2012/09/11