Messages in this thread | | | From | Martin Steigerwald <> | Subject | Re: Documentation on CFQ iosched parameters | Date | Tue, 23 Sep 2008 11:26:51 +0200 |
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Am Dienstag, 23. September 2008 schrieb Aaron Carroll: > Martin Steigerwald wrote: > > Hi! > > > > I am searching documentation about CFQ io scheduler. I can't find it in > > linux 2.6.26 Documentation directory. > > > > I found about these in german[1]: > > > > back_seek_max:16384 > > back_seek_penalty:2 > > fifo_expire_async:250 > > fifo_expire_sync:123 > > quantum:4 > > > > But I am completely missing about these: > > > > slice_async:40 > > Base length of an asynchronous queue timeslice (that is, how long the > queue has to dispatch requests each round). The actual timeslice > length is scaled by the I/O priority.
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Thanks. As I do not find documentation about CFQ at all, I think I need to create a new file from scratch... how about Documentation/block/cfq-iosched.txt?
For that I need some more information about CFQ. I found the following resources:
- CFQ V3 aka CFQ TS: http://lwn.net/Articles/143474/, http://lwn.net/Articles/114770/ and posts by Jens, http://lwn.net/Articles/113869/
- CFQ V2: Post by Jens, http://lwn.net/Articles/101029/
- CFQ: Post by Jens, http://lwn.net/Articles/22429/
- Documentation/block/as-iosched.txt / deadline-iosched.txt (as for how an IO scheduler can be documented)
Would that be what I should read in order to write such an documentation?
How about the relevance of CFQ and CFQ v2 stuff? What of it would be good to mention? I would like to limit documentation to what is still relevant for the current implementation of the IO scheduler. Should I mention its inheritance from SFQ - maybe in a small introduction and historic overview?
Ciao, -- Martin Steigerwald - team(ix) GmbH - http://www.teamix.de gpg: 19E3 8D42 896F D004 08AC A0CA 1E10 C593 0399 AE90 [unhandled content-type:application/pgp-signature] | |