Re: [Qemu-devel] [PATCH 05/10] tcg: Prepare TB invalidation for lockless TB lookup

[Sergey Fedorov]

On 19/07/16 11:32, Paolo Bonzini wrote:
>

It looks much better now :)

> When invalidating a translation block, set an invalid flag into the
> TranslationBlock structure first.  It is also necessary to check whether
> the target TB is still valid after acquiring 'tb_lock' but before calling
> tb_add_jump() since TB lookup is to be performed out of 'tb_lock' in
> future. Note that we don't have to check 'last_tb'; an already invalidated
> TB will not be executed anyway and it is thus safe to patch it.
>
> Suggested-by: Sergey Fedorov <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  cpu-exec.c              | 5 +++--
>  include/exec/exec-all.h | 2 ++
>  translate-all.c         | 3 +++
>  3 files changed, 8 insertions(+), 2 deletions(-)
(snip)
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index acda7b6..bc0bcc5 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -213,6 +213,8 @@ struct TranslationBlock {
>  #define CF_USE_ICOUNT  0x20000
>  #define CF_IGNORE_ICOUNT 0x40000 /* Do not generate icount code */
>  
> +    uint16_t invalid;

Why not "int"?

> +
>      void *tc_ptr;    /* pointer to the translated code */
>      uint8_t *tc_search;  /* pointer to search data */
>      /* original tb when cflags has CF_NOCACHE */
>

Thanks,
Sergey