Re: [Qemu-devel] [PATCH v3 00/17] tcg: tb_lock removal redux v3

[Alex Bennée]

Emilio G. Cota <address@hidden> writes:

> On Wed, May 30, 2018 at 16:05:14 -0700, Richard Henderson wrote:
>> On 05/30/2018 03:46 PM, Richard Henderson wrote:
>> > Thanks.  Queued to tcg-next.
>> Hmph.  Unqueued, at least for now.
>>
>> ERROR:/home/rth/work/qemu/qemu/accel/tcg/translate-all.c:615:page_unlock__debug:
>> assertion failed: (page_is_locked(pd))
>
> Gaah, sorry. In v3 forgot to call the lock__debug function from
> a successful trylock. I tested v3 on aarch64, which explains why
> I didn't catch the bug. Fixed now:
>
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -704,6 +704,7 @@ static bool page_entry_trylock(struct page_entry *pe)
>      if (!busy) {
>          g_assert(!pe->locked);
>          pe->locked = true;
> +        page_lock__debug(pe->pd);
>      }
>      return busy;
>  }
>
> I also added the following, which cannot hurt:
>
> diff --git a/exec.c b/exec.c
> index afc37e0..e874d67 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2493,6 +2493,7 @@ void memory_notdirty_write_complete(NotDirtyInfo *ndi)
>  {
>      if (ndi->pages) {
>          page_collection_unlock(ndi->pages);
> +        ndi->pages = NULL;
>      }
>
> (Note that calling page_collection_unlock twice on that pointer
> would blow up.)
>
> The above two one-liners are the only code changes between v3 and v4.
> I also added Alex's R-b tag for the qht patch.
>
> I've boot-tested v4 on aarch64, arm, x86_64-softmmu, riscv64, sh4,
> sparc, s390x, ppc64 and or1k, with and without TCG debug.
>
> You can fetch v4 from:
>   https://github.com/cota/qemu/tree/tb-lock-removal-redux-v4

I've just spun up v4 and it still works on aarch64 and now also passes
the coldfire test rich passed me. So have a:

Tested-by: Alex Bennée <address@hidden>

For those two.

>
> Thanks,
>
>               Emilio


--
Alex Bennée