Horton

Re: pread() and pwrite()

Jesper Pedersen <jesper.pedersen@redhat.com>

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From: Jesper Pedersen <jesper.pedersen@redhat.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@2ndquadrant.com>, Magnus Hagander <magnus@hagander.net>, Oskari Saarenmaa <os@ohmu.fi>, Pg Hackers <pgsql-hackers@postgresql.org>, Tobias Oberstein <tobias.oberstein@gmail.com>
Date: 2018-11-07T14:03:27Z
Lists: pgsql-hackers

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Hi,

On 11/7/18 7:26 AM, Jesper Pedersen wrote:
> On 11/6/18 4:04 PM, Thomas Munro wrote:
>> On Wed, Nov 7, 2018 at 4:42 AM Jesper Pedersen
>> Thanks!  Pushed.  I'll keep an eye on the build farm to see if
>> anything breaks on Cygwin or some other frankenOS.
>>
> 
> There is [1] on Andres' skink setup. Looking.
> 

Attached is a reproducer.

Adding the memset() command for the page makes valgrind happy.

Thoughts on how to proceed with this ? The report in [1] shows that 
there are a number of call sites where the page(s) aren't fully initialized.

[1] 
https://www.postgresql.org/message-id/3fe1e38a-fb70-6260-9300-ce67ede21c32%40redhat.com

Best regards,
  Jesper

Commits

  1. Use pg_pread() and pg_pwrite() for data files and WAL.

  2. Provide pg_pread() and pg_pwrite() for random I/O.

  3. Convert some long lists in configure.in to one-line-per-entry style.