tree 26a75dbdbcb6f442e999dcd8980cd81f19d42e5a
parent a6940a9e28bffeddf810af64c01026071244631b
author Barret Rhoden <brho@cs.berkeley.edu> 1502718321 -0400
committer Barret Rhoden <brho@cs.berkeley.edu> 1502744540 -0400

cons: Clamp the amount written to the console

Large writes to the console take a long time.  Serial writes of about a
page take O(100ms).  Our kernel is currently non-preemptive, which is
based on a model of syscalls not taking too long.

Limiting the write sizes to 80 (the width of an ancient console, which
Ron will love) cuts the syscall time down to a few ms, which is within
the quantum of a process.

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>