Project

General

Profile

Actions

Bug #8372

open

sync and async zio-s share the same task queues

Added by Andriy Gapon about 5 years ago. Updated about 5 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
zfs - Zettabyte File System
Start date:
2017-06-12
Due date:
% Done:

0%

Estimated time:
Difficulty:
Medium
Tags:
needs-triage
Gerrit CR:

Description

ZFS VDEV queuing mechanism is designed to prioritize sync I/O requests in order to minimize their latency and to reduce the effect of async I/O on the sync I/O.
But sync and async zio-s (both read and write) share the same task queues, so async zio-s can defeat the vdev queuing at a different level.
This is especially true when the zio-s require a lot of computational resources because of compression and cryptographic checksums.
My first idea was to use the "high" task queues for the sync zio-s, but I am not sure if those are properly sized for the potential high bandwidth of such requests.

Actions #1

Updated by Matthew Ahrens about 5 years ago

I think it would be fine to resize the "high" task queues to be appropriate for this use case.

Actions

Also available in: Atom PDF