Re: [Qemu-devel] [PATCH] RAMList: replace QemuMutex with CompatGMutex

[Paolo Bonzini <pbonzini@redhat.com>]

On 14/02/2018 09:49, Zihan Yang wrote:
> change the mutex member in RAMList structure from QemuMutex to CompatGMutex.
> qemu_mutex_init() is just deleted instead of being replaced with g_mutex_init()
> because there is no need to do initialize a mutex that is statically allocated.
> 
> Signed-off-by: Zihan Yang <whois.zihan.yang@gmail.com>

I'm not sure what is the advantage of this change.  QEMU is more or less
uniformly using QemuMutex and QemuCond.

Paolo

> ---
>  exec.c                 | 5 ++---
>  include/exec/ramlist.h | 2 +-
>  2 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index e8d7b33..90cdd05 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1423,12 +1423,12 @@ void qemu_flush_coalesced_mmio_buffer(void)
>  
>  void qemu_mutex_lock_ramlist(void)
>  {
> -    qemu_mutex_lock(&ram_list.mutex);
> +    g_mutex_lock(&ram_list.mutex);
>  }
>  
>  void qemu_mutex_unlock_ramlist(void)
>  {
> -    qemu_mutex_unlock(&ram_list.mutex);
> +    g_mutex_unlock(&ram_list.mutex);
>  }
>  
>  void ram_block_dump(Monitor *mon)
> @@ -3331,7 +3331,6 @@ void cpu_register_map_client(QEMUBH *bh)
>  
>  void cpu_exec_init_all(void)
>  {
> -    qemu_mutex_init(&ram_list.mutex);
>      /* The data structures we set up here depend on knowing the page size,
>       * so no more changes can be made after this point.
>       * In an ideal world, nothing we did before we had finished the
> diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
> index 2e2ac6c..24be5e4 100644
> --- a/include/exec/ramlist.h
> +++ b/include/exec/ramlist.h
> @@ -45,7 +45,7 @@ typedef struct {
>  } DirtyMemoryBlocks;
>  
>  typedef struct RAMList {
> -    QemuMutex mutex;
> +    CompatGMutex mutex;
>      RAMBlock *mru_block;
>      /* RCU-enabled, writes protected by the ramlist lock. */
>      QLIST_HEAD(, RAMBlock) blocks;
>