• Vivek Goyal's avatar
    cfq-iosched: Add documentation about idling · 4931402a
    Vivek Goyal authored
    There are always questions about why CFQ is idling on various conditions.
    Recent ones is Christoph asking again why to idle on REQ_NOIDLE. His
    assertion is that XFS is relying more and more on workqueues and is
    concerned that CFQ idling on IO from every workqueue will impact
    XFS badly.
    
    So he suggested that I add some more documentation about CFQ idling
    and that can provide more clarity on the topic and also gives an
    opprotunity to poke a hole in theory and lead to improvements.
    
    So here is my attempt at that. Any comments are welcome.
    Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
    Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
    4931402a
cfq-iosched.txt 5.66 KB