Horton

Re: Non-reproducible AIO failure

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Konstantin Knizhnik <knizhnik@garret.ru>
Cc: Dmitry Mityugov <dmitry.mityugov@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Nico Williams <nico@cryptonector.com>, Alexander Lakhin <exclusion@gmail.com>, Daniel Gustafsson <daniel@yesql.se>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, rmt@lists.postgresql.org
Date: 2025-09-03T19:42:06Z
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: Stop using enum bitfields due to bad code generation

  2. amcheck: Fix posting tree checks in gin_index_check()

  3. aio: Add missing memory barrier when waiting for IO handle

Hi,

On 2025-09-03 21:50:42 +0300, Konstantin Knizhnik wrote:
> On 03/09/2025 8:37 PM, Dmitry Mityugov wrote:
> Size of PgAioHandle is144 bytes. I wonder how critical for us is to save 9
> bytes for it (3 bytes vs 3 integers)?

Not that it makes that huge a difference, but due to alignment considerations
the size increase would be 12 bytes, not 9. Maybe that could be addressed by
more reordering though.


> Why not to use normal enums instead of bitfields and uint8 with type casts?

There are a lot of PgAioHandles when max_connections is large. In addition,
some workloads (e.g. network attached storage), one might need to increase
io_max_concurrency to actually be able to saturate storage.  An ~8% increase
in size isn't nothing when the baseline isn't small.

Greetings,

Andres Freund