Multi-threading access to device drivers.

[Poul-Henning Kamp]

Assume a device driver which is not Giant-handicapped.

Assume an I/O path which does not need Giant to get from
read(2) to the device driver.

Assume a SMP machine.

Assume a process with two threads on two CPUs, both
doing read(fd, buf, len) at the same time.

Should we let both reads into the driver at the same time ?

If so, which uio_offset do we hand them ?

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.