On 21/07/2016 10:36, Sergey Fedorov wrote:
> On 20/07/16 01:27, Paolo Bonzini wrote:
>>
>> ----- Original Message -----
>>> From: "Sergey Fedorov" <serge.f...@gmail.com>
>>> To: "Paolo Bonzini" <pbonz...@redhat.com>, qemu-devel@nongnu.org
>>> Cc: "sergey fedorov" <sergey.fedo...@linaro.org>, "alex bennee"
>>> <alex.ben...@linaro.org>
>>> Sent: Tuesday, July 19, 2016 9:56:49 PM
>>> Subject: Re: [PATCH 05/10] tcg: Prepare TB invalidation for lockless TB
>>> lookup
>>>
>>> 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 <serge.f...@gmail.com>
>>>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
>>>> ---
>>>> 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"?
>> There's a hole there, we may want to move something else so I
>> used a smaller data type. Even uint8_t would do.
>
> But could simple "bool" work as well here?
sizeof(bool) is sometimes 1 sometimes 4. Since in the future we might
want to pack TranslationBlock for better locality, I thought it was
better to stick with uint*_t.
Paolo
>
>>
>> Paolo
>>>> +
>>>> void *tc_ptr; /* pointer to the translated code */
>>>> uint8_t *tc_search; /* pointer to search data */
>
> Are you sure that the hole is over there, not here?
>
> Kind regards,
> Sergey
>
>>>> /* original tb when cflags has CF_NOCACHE */
>>>>
>>> Thanks,
>>> Sergey
>>>
>
>
>
