Page 88 - slides.dvi

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Operating
Other
Error
key
can
e.g.
e.g.
Device
most
some
Systems
useful
Caching:
to
system
system
Spooling:
—
printer)
I/O
work
Scheduling:
I/O
for
I/O
I/O
fast
calls
recover
error
handling:
ordering
queue
with
operating
for
reservation:
Subsystem
“single
system
Issues
I/O
logs
from
both
memory
output
disk
calls
hold
user”
performance
systems
for
acquiring
reads
requests
a
try
read,
holding
or
return
via
and
problem
devices
an
copy
device
device
of
fairness.
writes
which
error
releasing
.
.
reports.
per-device
data
can
number
exclusive
queue
unavailable,
serve
or
only
code
access
one
transient
to
a
when
write
an
request
device
I/O
at
a
failures,
time
request
etc.
(careful!)
(e.g.
84
fails