"Also sprach ptb:"
> 4) what the network device driver wants to do is be able to identify
> the difference between primary requests and retries, and delay
> retries (or repeat them internally) with some reasonable backoff
> scheme to give them more chance of working in the face of a
> brownout, but it has no way of doing that. You can make the problem
> go away by delaying retries yourself (is there a timedue field in
> requests, as well as a timeout field? If so, maybe that can be used
> to signal what kind of a request it is and how to treat it).
If one could set the
unsigned long start_time;
field in the outgoing retry request to now + 1 jiffy, that might be
helpful. I can't see a functionally significant use of this field at
present in the kernel ... ll_rw_blk rewrites the field when merging
requests and end_that_request then uses it for the accounting stats
(duration) __disk_stat_add(disk, ticks[rw], duration) which will add a
minus 1 at worst.
Shame there isn't a timedue field in the request struct.
Silly idea, maybe.
Peter
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