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

[Zihan Yang]

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

I see. QEMU uses some glib functions, like g_new, g_free, g_hash_table ,
g_assert and g_poll, so I thought there was a trend for making more use of
glib.
I get the point now.


2018-02-14 18:13 GMT+08:00 Paolo Bonzini <address@hidden>:

> 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 <address@hidden>
>
> 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;
> >
>
>