Re: AIO v2.5

Ranier Vilela <ranier.vf@gmail.com>

From: Ranier Vilela <ranier.vf@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Noah Misch <noah@leadboat.com>, 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>, Antonin Houska <ah@cybertec.at>
Date: 2025-04-03T16:46:39Z
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 aio: Fix reference to outdated name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.

Em qua., 2 de abr. de 2025 às 08:58, Andres Freund <andres@anarazel.de>
escreveu:

> Hi,
>
> I've pushed fixes for 1) and 2) and am working on 3).
>
Coverity has one report about this.

CID 1596092: (#1 of 1): Uninitialized scalar variable (UNINIT)
13. uninit_use_in_call: Using uninitialized value result_one. Field
result_one.result is uninitialized when calling pgaio_result_report.

Below not is a fix, but some suggestion:

diff --git a/src/backend/storage/buffer/bufmgr.c
b/src/backend/storage/buffer/bufmgr.c
index 1c37d7dfe2..b0f9ce452c 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -6786,6 +6786,8 @@ buffer_readv_encode_error(PgAioResult *result,
  else
  result->status = PGAIO_RS_WARNING;

+ result->result = 0;
+
  /*
  * The encoding is complicated enough to warrant cross-checking it against
  * the decode function.
@@ -6868,8 +6870,6 @@ buffer_readv_complete_one(PgAioTargetData *td, uint8
buf_off, Buffer buffer,
  /* Check for garbage data. */
  if (!failed)
  {
- PgAioResult result_one;
-
  if (!PageIsVerified((Page) bufdata, tag.blockNum, piv_flags,
  failed_checksum))
  {
@@ -6904,6 +6904,8 @@ buffer_readv_complete_one(PgAioTargetData *td, uint8
buf_off, Buffer buffer,
  */
  if (*buffer_invalid || *failed_checksum || *zeroed_buffer)
  {
+ PgAioResult result_one;
+
  buffer_readv_encode_error(&result_one, is_temp,
   *zeroed_buffer,
   *ignored_checksum,


1. I couldn't find the correct value to initialize the *result* field.
2. result_one can be reduced scope.

best regards,
Ranier Vilela