Describing how you use the file to the kernel

Posted Dec 9, 2024 23:10 UTC (Mon) by andresfreund (subscriber, #69562)
In reply to: Describing how you use the file to the kernel by NYKevin
Parent article: The return of RWF_UNCACHED

Agreed, there's lots of cases where this is legitimate. Even for longer lived files.

E.g. postgres won't fsync data files until a checkpoint, as all modifications would be performed again in case the system / the database crashes and performs journal replay. It'd cause a major performance regression to always fsync modified files before a process exits (PG is multi process for now, each connection can have an FD open for a file).