Re: [Qemu-devel] [patch v5 5/8] memory: introduce local lock for address space

[Avi Kivity <avi@redhat.com>]

On 10/29/2012 01:48 AM, Liu Ping Fan wrote:
> For those address spaces which want to be able out of big lock, they
> will be protected by their own local.
> 
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> ---
>  memory.c |   11 ++++++++++-
>  memory.h |    5 ++++-
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/memory.c b/memory.c
> index 2f68d67..ff34aed 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1532,9 +1532,15 @@ void memory_listener_unregister(MemoryListener *listener)
>      QTAILQ_REMOVE(&memory_listeners, listener, link);
>  }
>  
> -void address_space_init(AddressSpace *as, MemoryRegion *root)
> +void address_space_init(AddressSpace *as, MemoryRegion *root, bool lock)


Why not always use the lock?  Even if the big lock is taken, it doesn't
hurt.  And eventually all address spaces will be fine-grained.

>  {
>      memory_region_transaction_begin();
> +    if (lock) {
> +        as->lock = g_new(QemuMutex, 1);
> +        qemu_mutex_init(as->lock);
> +    } else {
> +        as->lock = NULL;
> +    }
>      as->root = root;
>      as->current_map = g_new(FlatView, 1);
>      flatview_init(as->current_map);
> @@ -1553,6 +1559,9 @@ void address_space_destroy(AddressSpace *as)
>      QTAILQ_REMOVE(&address_spaces, as, address_spaces_link);
>      address_space_destroy_dispatch(as);
>      flatview_destroy(as->current_map);
> +    if (as->lock) {
> +        g_free(as->lock);
> +    }
>      g_free(as->current_map);
>  }
>  
> diff --git a/memory.h b/memory.h
> index 79393f1..12d1c56 100644
> --- a/memory.h
> +++ b/memory.h
> @@ -22,6 +22,7 @@
>  #include "cpu-common.h"
>  #include "targphys.h"
>  #include "qemu-queue.h"
> +#include "qemu-thread.h"
>  #include "iorange.h"
>  #include "ioport.h"
>  #include "int128.h"
> @@ -164,6 +165,7 @@ typedef struct AddressSpace AddressSpace;
>   */
>  struct AddressSpace {
>      /* All fields are private. */
> +    QemuMutex *lock;
>      const char *name;
>      MemoryRegion *root;
>      struct FlatView *current_map;
> @@ -801,8 +803,9 @@ void mtree_info(fprintf_function mon_printf, void *f);
>   *
>   * @as: an uninitialized #AddressSpace
>   * @root: a #MemoryRegion that routes addesses for the address space
> + * @lock: if true, the physmap protected by local lock, otherwise big lock
>   */
> -void address_space_init(AddressSpace *as, MemoryRegion *root);
> +void address_space_init(AddressSpace *as, MemoryRegion *root, bool lock);
>  
>  
>  /**
> 


-- 
error compiling committee.c: too many arguments to function