The APIs using qemu_global_mutex now follow the Big QEMU Lock (BQL)
nomenclature. It's a little strange that the actual QemuMutex variable
that embodies the BQL is called qemu_global_mutex instead of qemu_bql.
Rename it for consistency.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 system/cpus.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/system/cpus.c b/system/cpus.c
index eb24a4db8e..138720a540 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -65,7 +65,7 @@
 
 #endif /* CONFIG_LINUX */
 
-static QemuMutex qemu_global_mutex;
+static QemuMutex qemu_bql;
 
 /*
  * The chosen accelerator is supposed to register this.
@@ -389,14 +389,14 @@ void qemu_init_cpu_loop(void)
     qemu_init_sigbus();
     qemu_cond_init(&qemu_cpu_cond);
     qemu_cond_init(&qemu_pause_cond);
-    qemu_mutex_init(&qemu_global_mutex);
+    qemu_mutex_init(&qemu_bql);
 
     qemu_thread_get_self(&io_thread);
 }
 
 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
 {
-    do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
+    do_run_on_cpu(cpu, func, data, &qemu_bql);
 }
 
 static void qemu_cpu_stop(CPUState *cpu, bool exit)
@@ -428,7 +428,7 @@ void qemu_wait_io_event(CPUState *cpu)
             slept = true;
             qemu_plugin_vcpu_idle_cb(cpu);
         }
-        qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
+        qemu_cond_wait(cpu->halt_cond, &qemu_bql);
     }
     if (slept) {
         qemu_plugin_vcpu_resume_cb(cpu);
@@ -502,7 +502,7 @@ void qemu_bql_lock_impl(const char *file, int line)
     QemuMutexLockFunc bql_lock = qatomic_read(&qemu_bql_mutex_lock_func);
 
     g_assert(!qemu_bql_locked());
-    bql_lock(&qemu_global_mutex, file, line);
+    bql_lock(&qemu_bql, file, line);
     set_bql_locked(true);
 }
 
@@ -510,17 +510,17 @@ void qemu_bql_unlock(void)
 {
     g_assert(qemu_bql_locked());
     set_bql_locked(false);
-    qemu_mutex_unlock(&qemu_global_mutex);
+    qemu_mutex_unlock(&qemu_bql);
 }
 
 void qemu_cond_wait_bql(QemuCond *cond)
 {
-    qemu_cond_wait(cond, &qemu_global_mutex);
+    qemu_cond_wait(cond, &qemu_bql);
 }
 
 void qemu_cond_timedwait_bql(QemuCond *cond, int ms)
 {
-    qemu_cond_timedwait(cond, &qemu_global_mutex, ms);
+    qemu_cond_timedwait(cond, &qemu_bql, ms);
 }
 
 /* signal CPU creation */
@@ -571,7 +571,7 @@ void pause_all_vcpus(void)
     replay_mutex_unlock();
 
     while (!all_vcpus_paused()) {
-        qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
+        qemu_cond_wait(&qemu_pause_cond, &qemu_bql);
         CPU_FOREACH(cpu) {
             qemu_cpu_kick(cpu);
         }
@@ -649,7 +649,7 @@ void qemu_init_vcpu(CPUState *cpu)
     cpus_accel->create_vcpu_thread(cpu);
 
     while (!cpu->created) {
-        qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
+        qemu_cond_wait(&qemu_cpu_cond, &qemu_bql);
     }
 }
 
-- 
2.42.0

Hi Stefan,

On 29/11/23 22:26, Stefan Hajnoczi wrote:
> The APIs using qemu_global_mutex now follow the Big QEMU Lock (BQL)
> nomenclature. It's a little strange that the actual QemuMutex variable
> that embodies the BQL is called qemu_global_mutex instead of qemu_bql.
> Rename it for consistency.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   system/cpus.c | 20 ++++++++++----------
>   1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/system/cpus.c b/system/cpus.c
> index eb24a4db8e..138720a540 100644
> --- a/system/cpus.c
> +++ b/system/cpus.c
> @@ -65,7 +65,7 @@
>   
>   #endif /* CONFIG_LINUX */
>   
> -static QemuMutex qemu_global_mutex;
> +static QemuMutex qemu_bql;

I thought we were using _cond/_sem/_mutex suffixes, but
this is not enforced:

$ git grep -hE 'Qemu(Cond|Mutex|Semaphore) [a-zA-Z]' \
   | sed -e 's/static //' -e 's/extern //' -e 's/^ *//' \
   | sort -u
QemuCond comp_done_cond;
QemuCond cond;
QemuCond decomp_done_cond;
QemuCond event_complete_cond;
QemuCond exclusive_cond;
QemuCond exclusive_resume;
QemuCond fwnmi_machine_check_interlock_cond;
QemuCond handle_apdu_cond;
QemuCond init_done_cond;    /* is thread initialization done? */
QemuCond key_cond;
QemuCond mutex_cond;
QemuCond page_cond;
QemuCond page_request_cond;
QemuCond qemu_cpu_cond;
QemuCond qemu_pause_cond;
QemuCond qemu_work_cond;
QemuCond request_cond;
QemuCond reset_cond;
QemuCond thr_cond;
QemuCond thread_cond;
QemuCond worker_stopped;
QemuMutex active_timers_lock;
QemuMutex aio_context_list_lock;
QemuMutex bitmap_mutex;
QemuMutex blkio_lock;
QemuMutex chr_write_lock;
QemuMutex cmdq_mutex;
QemuMutex colo_compare_mutex;
QemuMutex comp_done_lock;
QemuMutex counts_mutex;
QemuMutex decomp_done_lock;
QemuMutex dirty_bitmap_mutex;
QemuMutex dirtylimit_mutex;
QemuMutex error_mutex;
QemuMutex event_list_mutex;
QemuMutex event_mtx;
QemuMutex evlock;
QemuMutex free_page_lock;
QemuMutex global_mutex;
QemuMutex gnt_lock;
QemuMutex handle_apdu_mutex;
QemuMutex handlers_mutex;
QemuMutex init_done_lock;
QemuMutex intp_mutex; /* protect the intp_list IRQ state */
QemuMutex io_mutex;
QemuMutex iommu_lock;
QemuMutex irq_level_lock[REMOTE_IOHUB_NB_PIRQS];
QemuMutex job_mutex;
QemuMutex key_mutex;
QemuMutex kml_slots_lock;
QemuMutex lock;
QemuMutex m;
QemuMutex map_client_list_lock;
QemuMutex migration_threads_lock;
QemuMutex mon_fdsets_lock;
QemuMutex mon_lock;
QemuMutex monitor_lock;
QemuMutex mutex;
QemuMutex output_mutex;
QemuMutex page_mutex;
QemuMutex page_request_mutex;
QemuMutex pending_out_mutex;
QemuMutex port_lock;
QemuMutex postcopy_prio_thread_mutex;
QemuMutex qemu_cpu_list_lock;
QemuMutex qemu_file_lock;
QemuMutex qemu_global_mutex;
QemuMutex qemu_sigp_mutex;
QemuMutex qjack_shutdown_lock;
QemuMutex qmp_queue_lock;
QemuMutex queue_mutex;
QemuMutex queued_requests_lock; /* protects queued_requests */
QemuMutex ram_block_discard_disable_mutex;
QemuMutex rcu_registry_lock;
QemuMutex rcu_sync_lock;
QemuMutex readdir_mutex_L;
QemuMutex reqs_lock;
QemuMutex requests_lock;
QemuMutex rp_mutex;    /* We send replies from multiple threads */
QemuMutex rsp_mutex;
QemuMutex rx_queue_lock;
QemuMutex sigbus_mutex;
QemuMutex sint_routes_mutex;
QemuMutex src_page_req_mutex;
QemuMutex start_lock;
QemuMutex target_fd_trans_lock;
QemuMutex thr_mutex;
QemuMutex thread_lock;
QemuMutex vdev_mutex;
QemuMutex vmstop_lock;
QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
QemuMutex work_mutex;
QemuMutex xen_timers_lock;
QemuMutex yank_lock;
QemuSemaphore channels_ready;
QemuSemaphore colo_exit_sem;
QemuSemaphore colo_incoming_sem;
QemuSemaphore init_done_sem; /* is thread init done? */
QemuSemaphore pause_sem;
QemuSemaphore postcopy_pause_sem;
QemuSemaphore postcopy_pause_sem_dst;
QemuSemaphore postcopy_pause_sem_fast_load;
QemuSemaphore postcopy_pause_sem_fault;
QemuSemaphore postcopy_qemufile_dst_done;
QemuSemaphore postcopy_qemufile_src_sem;
QemuSemaphore rate_limit_sem;
QemuSemaphore rp_pong_acks;
QemuSemaphore rp_sem;
QemuSemaphore sem;
QemuSemaphore sem_sync;
QemuSemaphore sem_thread;
QemuSemaphore wait_unplug_sem;

So:
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

On Thu, Nov 30, 2023 at 02:44:07PM +0100, Philippe Mathieu-Daudé wrote:
> Hi Stefan,
> 
> On 29/11/23 22:26, Stefan Hajnoczi wrote:
> > The APIs using qemu_global_mutex now follow the Big QEMU Lock (BQL)
> > nomenclature. It's a little strange that the actual QemuMutex variable
> > that embodies the BQL is called qemu_global_mutex instead of qemu_bql.
> > Rename it for consistency.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >   system/cpus.c | 20 ++++++++++----------
> >   1 file changed, 10 insertions(+), 10 deletions(-)
> > 
> > diff --git a/system/cpus.c b/system/cpus.c
> > index eb24a4db8e..138720a540 100644
> > --- a/system/cpus.c
> > +++ b/system/cpus.c
> > @@ -65,7 +65,7 @@
> >   #endif /* CONFIG_LINUX */
> > -static QemuMutex qemu_global_mutex;
> > +static QemuMutex qemu_bql;
> 
> I thought we were using _cond/_sem/_mutex suffixes, but
> this is not enforced:

I'm open to alternative names. Here are some I can think of:
- big_qemu_lock (although grepping for "bql" won't find it)
- qemu_bql_mutex

If there is no strong feeling about this then let's leave it at
qemu_bql. Otherwise, please discuss.

Thanks,
Stefan

On 11/29/23 22:26, Stefan Hajnoczi wrote:
> The APIs using qemu_global_mutex now follow the Big QEMU Lock (BQL)
> nomenclature. It's a little strange that the actual QemuMutex variable
> that embodies the BQL is called qemu_global_mutex instead of qemu_bql.
> Rename it for consistency.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>


Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.