Re: [PATCH] block: fix request sorting at unplug

[Jens Axboe]

On 2011-04-02 17:37, Konstantin Khlebnikov wrote:
> Comparison function for list_sort() must be anticommutative,
> otherwise it is not sorting in ordinary meaning.
> 
> But fortunately list_sort() always check ((*cmp)(priv, a, b) <= 0)
> it not distinguish negative and zero, so comparison function can
> implement only less-or-equal instead of full three-way comparison.

Thanks, good catch! It's an optimization, so no breakage. But if you end
up often having > 1 queue plugged, it's a good optimization.

-- 
Jens Axboe

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