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    SubjectRe: [PATCH] deadline io scheduler
    On Thu, Sep 26 2002, Daniel Pittman wrote:
    > On Thu, 26 Sep 2002, Jens Axboe wrote:
    > > On Wed, Sep 25 2002, Andrew Morton wrote:
    > [...]
    > > writes_starved. This controls how many times reads get preferred over
    > > writes. The default is 2, which means that we can serve two batches of
    > > reads over one write batch. A value of 4 would mean that reads could
    > > skip ahead of writes 4 times. A value of 1 would give you 1:1
    > > read:write, ie no read preference. A silly value of 0 would give you
    > > write preference, always.
    > Actually, a value of zero doesn't sound completely silly to me, right
    > now, since I have been doing a lot of thinking about video capture
    > recently.
    > How much is it going to hurt a filesystem like ext[23] if that value is
    > set to zero while doing large streaming writes -- something like
    > (almost) uncompressed video at ten to twenty meg a second, for
    > gigabytes?

    You are going to stalll all reads indefinately :-)

    > This is a situation where, for a dedicated machine, delaying reads
    > almost forever is actually a valuable thing. At least, valuable until it
    > stops the writes from being able to proceed.

    Well 0 should achieve that quite fine

    Jens Axboe

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