Horton

Re: better atomics - v0.5

Andres Freund <andres@2ndquadrant.com>

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From: Andres Freund <andres@2ndquadrant.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Peter Geoghegan <pg@heroku.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Ants Aasma <ants@cybertec.at>
Date: 2014-07-13T19:20:23Z
Lists: pgsql-hackers 
On 2014-07-10 08:46:55 +0530, Amit Kapila wrote:
> As per my understanding of the general theory around barriers,
> read and write are defined to avoid reordering due to compiler and
> full memory barriers are defined to avoid reordering due to
> processors.

No, that's not the case. There's several processors where write/read
barriers are an actual thing on the hardware level.

Greetings,

Andres Freund

-- 
 Andres Freund	                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Avoid the use of a separate spinlock to protect a LWLock's wait queue.

  2. Improve LWLock scalability.

  3. Reduce the number of semaphores used under --disable-spinlocks.

  4. Alter the configure script to fail immediately if the C compiler does not