On Thu, 18 Mar 1999 20:50:36 +0100 (CET), Ingo Molnar
<mingo@chiara.csoma.elte.hu> said:
>> Another point is that IN_ORDER seems to be called only for two requests
>> on the same device, so no idea why it compares the device numbers.
To distinguish between partition access on the same major device.
> no, all requests (for all devices) are in a single 'queue'. (Per-major
> device queues is candidate 2.3 feature, it's really simple)
No, each major has its own queue, defined either by the
blkdev[major].queue() strategy function or by
blkdev[major].current_request. As far as IN_ORDER is concerned, it will
only ever look at one such queue at a time.
You're probably thinking of the global request array "all_requests", but
that is just a global, static pool from which we allocate request
structs. Active requests are most definitely kept on separate queues
for each device.
--Stephen
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