Re: spinaphore conceptual draft (was discussion of RT patch)

[Kyle Moffett <mrmacman_g4@mac.com>]

On May 29, 2005, at 09:29:37, Joe Seigh wrote:
> If you went with a bakery algorithm and could tolerate FIFO service  
> order,
> you could use the expected service time as the ticket increment value
> instead of 1.  Before a thread gets a ticket, it examines the  
> expected queue
> wait time, the difference between the current ticket and the next  
> available
> ticket, to decide which increment to be applied to the next ticket  
> value.
> The two possible increment values would be the uncontended resource  
> service
> time and that value plus thread suspend/resume overhead.  If the  
> expected
> wait time is greater than the latter, it uses the latter as the  
> increment
> value and suspends rather than spins.

Ah, interesting idea. Perhaps we ought to try implementing several of  
the
ideas and benchmarking them.  I'll work on a user-space operable  
version of
my naive spinaphores, as well as an optimized assembly version, if I can
find the time in the next day or so.

Cheers,
Kyle Moffett

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