Horton

Re: AIO v2.5

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Noah Misch <noah@leadboat.com>
Cc: Antonin Houska <ah@cybertec.at>, pgsql-hackers@postgresql.org, Thomas Munro <thomas.munro@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Robert Haas <robertmhaas@gmail.com>, Jakub Wartak <jakub.wartak@enterprisedb.com>, Jelte Fennema-Nio <postgres@jeltef.nl>
Date: 2025-03-25T01:40:47Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. aio: Fix assertion, clarify README

  2. aio: Fix reference to outdated name

  3. aio: Fix possible state confusions due to interrupt processing

  4. aio: Improve debug logging around waiting for IOs

  5. aio: Fix crash potential for pg_aios views due to late state update

  6. Increase BAS_BULKREAD based on effective_io_concurrency

  7. localbuf: Add Valgrind buffer access instrumentation

  8. aio: Make AIO more compatible with valgrind

  9. aio: Avoid spurious coverity warning

  10. tests: Fix incompatibility of test_aio with *_FORCE_RELEASE

  11. tests: Cope with WARNINGs during failed CREATE DB on windows

  12. aio: Add errcontext for processing I/Os for another backend

  13. aio: Add README.md explaining higher level design

  14. aio: Minor comment improvements

  15. aio: Add test_aio module

  16. aio: Add pg_aios view

  17. docs: Add acronym and glossary entries for I/O and AIO

  18. Enable IO concurrency on all systems

  19. read_stream: Introduce and use optional batchmode support

  20. docs: Reframe track_io_timing related docs as wait time

  21. bufmgr: Use AIO in StartReadBuffers()

  22. bufmgr: Implement AIO read support

  23. aio: Add WARNING result status

  24. Let caller of PageIsVerified() control ignore_checksum_failure

  25. pgstat: Allow checksum errors to be reported in critical sections

  26. Add errhint_internal()

  27. localbuf: Track pincount in BufferDesc as well

  28. aio, bufmgr: Comment fixes/improvements

  29. Fix mis-attribution of checksum failure stats to the wrong database

  30. aio: Implement support for reads in smgr/md/fd

  31. aio: Add io_method=io_uring

  32. aio: Add liburing dependency

  33. aio: Rename pgaio_io_prep_* to pgaio_io_start_*

  34. aio: Pass result of local callbacks to ->report_return

  35. aio: Be more paranoid about interrupts

  36. Redefine max_files_per_process to control additionally opened files

  37. aio: Change prefix of PgAioResultStatus values to PGAIO_RS_

  38. bufmgr: Improve stats when a buffer is read in concurrently

  39. aio: Add io_method=worker

  40. aio: Infrastructure for io_method=worker

  41. aio: Add core asynchronous I/O infrastructure

  42. aio: Basic subsystem initialization

  43. tests: Expand temp table tests to some pin related matters

  44. localbuf: Introduce FlushLocalBuffer()

  45. localbuf: Introduce TerminateLocalBufferIO()

  46. localbuf: Fix dangerous coding pattern in GetLocalVictimBuffer()

  47. localbuf: Introduce StartLocalBufferIO()

  48. localbuf: Introduce InvalidateLocalBuffer()

  49. Allow lwlocks to be disowned

  50. Make jsonb casts to scalar types translate JSON null to SQL NULL.

  51. bufmgr/smgr: Don't cross segment boundaries in StartReadBuffers()

  52. Use aux process resource owner in walsender

  53. bufmgr: Return early in ScheduleBufferTagForWriteback() if fsync=off

Hi,

On 2025-03-23 09:32:48 -0700, Noah Misch wrote:
> Another candidate description string:
> 
> AIO_COMPLETED_SHARED	"Waiting for another process to complete IO."

I liked that one and adopted it.


> > A more minimal change would be to narrow AIO_IO_URING_COMPLETION to
> > "execution" or something like that, to hint at a separation between the raw IO
> > being completed and the IO, including the callbacks completing.
> 
> Yes, that would work for me.

I updated both the name and the description of this one to EXECUTION, but I'm
not sure I like it for the name...


> > > > --- a/doc/src/sgml/config.sgml
> > > > +++ b/doc/src/sgml/config.sgml
> > > > @@ -2710,6 +2710,12 @@ include_dir 'conf.d'
> > > >              <literal>worker</literal> (execute asynchronous I/O using worker processes)
> > > >             </para>
> > > >            </listitem>
> > > > +          <listitem>
> > > > +           <para>
> > > > +            <literal>io_uring</literal> (execute asynchronous I/O using
> > > > +            io_uring, if available)
> > >
> > > I feel the "if available" doesn't quite fit, since we'll fail if unavailable.
> > > Maybe just "(execute asynchronous I/O using Linux io_uring)" with "Linux"
> > > there to reduce surprise on other platforms.
> > 
> > You're right, the if available can be misunderstood. But not mentioning that
> > it's an optional dependency seems odd too. What about something like
> > 
> >            <para>
> >             <literal>io_uring</literal> (execute asynchronous I/O using
> >             io_uring, requires postgres to have been built with
> >             <link linkend="configure-option-with-liburing"><option>--with-liburing</option></link> /
> >             <link linkend="configure-with-liburing-meson"><option>-Dliburing</option></link>)
> >            </para>
> 
> I'd change s/postgres to have been built/a build with/ since the SGML docs
> don't use the term "postgres" that way.  Otherwise, that works for me.

Went with that.

Greetings,

Andres Freund