Re: [PATCH 2/2] cfq-iosched: Take care of corner cases of group losing share due to deletion

From: Jeff Moyer
Date: Wed Dec 09 2009 - 14:06:27 EST


Vivek Goyal <vgoyal@xxxxxxxxxx> writes:

> Reported-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>

> + /*
> + * If think times is less than a jiffy than ttime_mean=0 and above
> + * will not be true. It might happen that slice has not expired yet
> + * but will expire soon (4-5 ns) during select_queue(). To cover the

4-5ns? I'm not sure why you chose these numbers. Is that what you saw
in testing? Anyway, I'm ok with the change, I dislike the reference to
time when a single jiffy could be up to 10ms.

Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
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