Re: [Qemu-devel] [PATCH v3 27/29] memory: replace cpu_physical_memory_reset_dirty() with test-and-clear

[Aurelien Jarno]

On 2015-05-26 18:55, Paolo Bonzini wrote:
> From: Stefan Hajnoczi <address@hidden>
> 
> The cpu_physical_memory_reset_dirty() function is sometimes used
> together with cpu_physical_memory_get_dirty().  This is not atomic since
> two separate accesses to the dirty memory bitmap are made.
> 
> Turn cpu_physical_memory_reset_dirty() and
> cpu_physical_memory_clear_dirty_range_type() into the atomic
> cpu_physical_memory_test_and_clear_dirty().
> 
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> Message-Id: <address@hidden>
> Reviewed-by: Fam Zheng <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  cputlb.c                |  4 ++--
>  exec.c                  | 23 +++++++++++++++++------
>  include/exec/ram_addr.h | 33 ++++++++++-----------------------
>  memory.c                | 11 ++++-------
>  4 files changed, 33 insertions(+), 38 deletions(-)

...

> diff --git a/exec.c b/exec.c
> index 4cd18ff..7552363 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -856,16 +856,27 @@ static void tlb_reset_dirty_range_all(ram_addr_t start, 
> ram_addr_t length)
>  }
>  
>  /* Note: start and end must be within the same ram block.  */
> -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length,
> -                                     unsigned client)
> +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
> +                                              ram_addr_t length,
> +                                              unsigned client)
>  {
> -    if (length == 0)
> -        return;
> -    cpu_physical_memory_clear_dirty_range_type(start, length, client);
> +    unsigned long end, page;
> +    bool dirty;
> + 

   ^

git am complains about the above added space.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
address@hidden                 http://www.aurel32.net