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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-08-03 13:16:15 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:43:55 -0700 |
| commit | 0d8ee37e2fcb7b77b9c5dee784beca5a215cad4c (patch) | |
| tree | 6e7661bf5231b4c48a6681a9fa8e8ede7915d0a7 /kernel/sched | |
| parent | 1331e7a1bbe1f11b19c4327ba0853bee2a606543 (diff) | |
rcu: Disallow callback registry on offline CPUs
Posting a callback after the CPU_DEAD notifier effectively leaks
that callback unless/until that CPU comes back online. Silence is
unhelpful when attempting to track down such leaks, so this commit emits
a WARN_ON_ONCE() and unconditionally leaks the callback when an offline
CPU attempts to register a callback. The rdp->nxttail[RCU_NEXT_TAIL] is
set to NULL in the CPU_DEAD notifier and restored in the CPU_UP_PREPARE
notifier, allowing _call_rcu() to determine exactly when posting callbacks
is illegal.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/sched')
0 files changed, 0 insertions, 0 deletions