| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Andres Freund <andres(at)anarazel(dot)de> |
| Cc: | Sokolov Yura <funny(dot)falcon(at)postgrespro(dot)ru>, Robert Haas <robertmhaas(at)gmail(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, Jesper Pedersen <jesper(dot)pedersen(at)redhat(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Fix performance of generic atomics |
| Date: | 2017-09-06 19:54:20 |
| Message-ID: | 9878.1504727660@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
I wrote:
> Ah. I was not thinking of touching pg_atomic_read_u32/u64_impl,
> although now that you mention it, it's not clear to me why we
> couldn't simplify
> - return *(&ptr->value);
> + return ptr->value;
Just to check, I applied that change to pg_atomic_read_u32_impl and
pg_atomic_read_u64_impl, and recompiled. I get bit-for-bit the
same backend executable. Maybe it would have an effect on some
other compiler, but I doubt it, except perhaps at -O0.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2017-09-06 20:03:56 | Re: why not parallel seq scan for slow functions |
| Previous Message | Robert Haas | 2017-09-06 19:53:03 | Re: why not parallel seq scan for slow functions |