From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40674) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBLHS-0008Ln-F7 for qemu-devel@nongnu.org; Tue, 11 Sep 2012 03:53:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TBLHR-0007Rn-Et for qemu-devel@nongnu.org; Tue, 11 Sep 2012 03:53:10 -0400 Received: from mail-ob0-f173.google.com ([209.85.214.173]:38954) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBLHR-0007Gb-A1 for qemu-devel@nongnu.org; Tue, 11 Sep 2012 03:53:09 -0400 Received: by mail-ob0-f173.google.com with SMTP id ta14so286204obb.4 for ; Tue, 11 Sep 2012 00:53:09 -0700 (PDT) From: Liu Ping Fan Date: Tue, 11 Sep 2012 15:51:51 +0800 Message-Id: <1347349912-15611-11-git-send-email-qemulist@gmail.com> In-Reply-To: <1347349912-15611-1-git-send-email-qemulist@gmail.com> References: <1347349912-15611-1-git-send-email-qemulist@gmail.com> Subject: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jan Kiszka , Marcelo Tosatti , Avi Kivity , Anthony Liguori , Paolo Bonzini From: Liu Ping Fan 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 --- 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 #include #include +#include #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