On Wed, May 11, 2016 at 4:54 PM, Dmitry Stogov <dmitry@zend.com> wrote:
> Hi,
>
>
> Nikita, please review the patch
> https://gist.github.com/dstogov/06116f1610f45f8152ine3a9927c6c243ac
>
> It's the next attempt to use the single stack for all generators.
>
> Now I don't see any problems or BC breaks.
>
>
> In case "yield" is used as an expression in context of function call. e.g.
> var_dump(yield), engine backups and then restores active call frame chain.
>
>
> Bob tested the patch on application that intensively uses generators, and
> reported:
>
> 15% less L2 cache loads
>
> 20% less cycle stalls due to memory subsystem
>
> 3% more CPU_CLOCK_UNHALTED due to additional freeze/restore.
>
>
> I'm going to commit this patch tomorrow.
>
The patch looks fine to me.
From my own testing with a "Hello World" Aerys server, after multiple
benchmark runs it previously started to mmap+munmap two new MM segments on
each request, leading to a decline from 50k rps to 5k. With the patch this
no longer occurs and the rps is stable at > 50k rps. (Though that may be
more luck than anything.)
Nikita
