Horton

Re: pg_preadv() and pg_pwritev()

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-01-11T02:59:42Z
Lists: pgsql-hackers 
On Mon, Jan 11, 2021 at 3:34 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> On Wed, Dec 23, 2020 at 12:06 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> > On Mon, Dec 21, 2020 at 11:40 AM Andres Freund <andres@anarazel.de> wrote:
> > > Can we come up with a better name than 'uio'? I find that a not exactly
> > > meaningful name.
> >
> > Ok, let's try port/pg_iovec.h.
>
> I pushed it with that name, and a couple more cosmetic changes.  I'll
> keep an eye on the build farm.

Since only sifaka has managed to return a result so far (nice CPU), I
had plenty of time to notice that macOS Big Sur has introduced
preadv/pwritev.  They were missing on Catalina[1].

[1] https://cirrus-ci.com/task/6002157537198080

Commits

  1. Improve our heuristic for selecting PG_SYSROOT on macOS.

  2. Move our p{read,write}v replacements into their own files.

  3. Don't use elog() in src/port/pwrite.c.

  4. Use vectored I/O to fill new WAL segments.

  5. Provide pg_preadv() and pg_pwritev().