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Date: Mon, 11 Oct 2004 14:42:34 -0400 (EDT)
From: Robert Watson <rwatson@FreeBSD.org>
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To: John Baldwin <jhb@FreeBSD.org>
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Subject: Re: cvs commit: src/sys/dev/random randomdev_soft.c
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On Mon, 11 Oct 2004, John Baldwin wrote:

> On Saturday 09 October 2004 06:07 pm, Robert Watson wrote:
> > On Sat, 9 Oct 2004, Robert Watson wrote:
> > >   - When reaping harvested entries from the queue, move all entries from
> > >     the queue at once, and when done with them, insert them all into a
> > >     thread-local queue for processing; then insert them all into the
> > >     empty fifo at once.  This reduces O(4n) mutex operations to O(2)
> > >     mutex operations per wakeup.
> >
> > Right now we do a slightly harmful O(2N) walk of the records to move them
> > to a thread-local queue.  It would be very nice to have an O(1) tailq (and
> > other list) "move them all" operation to move all entries to a local head.
> > This would also be useful when dealing with other work queues in worker
> > threads, such as bio queues, etc.
> 
> Like TAILQ_CONCAT? :)

Exactly like that!

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org      Principal Research Scientist, McAfee Research