tree 52782cc1d78c24030d627f719cdaa29846c42efb
parent 0361e02342f60b64a7075755d5851ed4e6f98c7d
author Robert Richter <robert.richter@amd.com> 1286219376 +0200
committer Robert Richter <robert.richter@amd.com> 1286897106 +0200

oprofile: disable write access to oprofilefs while profiler is running

Oprofile counters are setup when profiling is disabled. Thus, writing
to oprofilefs has no immediate effect. Changes are updated only after
oprofile is reenabled.

To keep userland and kernel states synchronized, we now allow
configuration of oprofile only if profiling is disabled.  In this case
it checks if the profiler is running and then disables write access to
oprofilefs by returning -EBUSY. The change should be backward
compatible with current oprofile userland daemon.

Acked-by: Maynard Johnson <maynardj@us.ibm.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>