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FS#22605 - [udev] Set scheduler for no SSD

Attached to Project: Arch Linux
Opened by Sébastien Luttringer (seblu) - Tuesday, 25 January 2011, 22:14 GMT
Last edited by Thomas Bächler (brain0) - Saturday, 29 January 2011, 06:02 GMT
Task Type Feature Request
Category Packages: Core
Status Closed
Assigned To Tobias Powalowski (tpowa)
Thomas Bächler (brain0)
Architecture All
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


I propose to add the following attached file (or content in 81-archlinux.rules) in /lib/udev/rules.d/

to set noop as scheduler for ssd and no rotational disk as explain in

This task depends upon

Closed by  Thomas Bächler (brain0)
Saturday, 29 January 2011, 06:02 GMT
Reason for closing:  Won't implement
Comment by Thomas Bächler (brain0) - Wednesday, 26 January 2011, 07:53 GMT
As far as I know, the cfq scheduler is designed to recognize SSDs and behave accordingly. Setting the noop scheduler is likely to reduce the read performance. I can't be sure, I'll have to find a reference.
Comment by Dan McGee (toofishes) - Saturday, 29 January 2011, 00:10 GMT
If you look at block/cfq-iosched.c, you'll see a few calls to blk_queue_nonrot() that "do the right thing" if they drive is non-rotational- idling is skipped, seektime is adjusted, etc. So there is no need for these changes to be an Arch default.