| From: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Julien Rouhaud <julien(dot)rouhaud(at)dalibo(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Josh Berkus <josh(at)agliodbs(dot)com>, "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com>, Peter Geoghegan <pg(at)heroku(dot)com>, Noah Misch <noah(at)leadboat(dot)com>, David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Magnus Hagander <magnus(at)hagander(dot)net>, Bruce Momjian <bruce(at)momjian(dot)us>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Rename max_parallel_degree? |
| Date: | 2016-09-17 06:40:24 |
| Message-ID: | CAA4eK1+6SX482mh1bGUqqOGh=N5vcoTcByD2+GOW6ovsi4FVdA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Fri, Sep 16, 2016 at 11:54 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> + /*
> + * We need a write barrier to make sure the update of
> + * parallel_terminate_count is done before the store to in_use
> + */
>
> Does the order actually matter here?
>
I think so. If slot->in_use is reordered before the check of
is_parallel_worker, then it is possible that concurrent registration
of worker can mark the is_parallel_worker as false before we check the
flag here. See explanation in previous e-mail [1].
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andreas Karlsson | 2016-09-17 09:39:35 | Re: OpenSSL 1.1 breaks configure and more |
| Previous Message | Dilip Kumar | 2016-09-17 05:56:55 | Re: Speed up Clog Access by increasing CLOG buffers |