On Tue, Sep 23 2008, Aaron Carroll wrote: > 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. > > >slice_async_rq:2 > > The base number of requests per round for asynchronous queues. Like > slice_async, the actual maximum is a function of slice_async_rq and I/O > priority. > > >slice_idle:6 > > How long to wait for processes to produce more I/O before switching > queues. This is for anticipation of sequential I/O, and more even disk > time distribution for processes doing back to back synchronous I/Os. > > >slice_sync:100 > > Same as slice_async, but for synchronous requests. Nothing further to add, Aaron nailed them. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
